The Journal for Equine Nutrition - Summer '21

First Issue The Journal for Equine Nutrition Professor Jo-Anne Murray, PhD, MSc, PgDip, PgCert, BSc (Hons), BHSII, RNutr, PFHEA, FRSB University of Glasgow Dr. Simon Daniels, PhD, PgCert, BSc (Hons), SFHEA, R.Anim.Sci Senior Lecturer at Royal Agricultural University Dr. Stephanie Wood, PhD Equine Nutrition, PgDip, BSc (Hons), RNutr (Animal), R.Anim.Tech Director of Science and Nutrition at Feedmark Abigail Malone, BSc Senior Nutritionist at Feedmark PB 1The Journal for Equine Nutrition is FREE. To get every edition of The JEN to your inbox for free, SIGN UP HERE You will receive no marketing literature, and you will be the first to receive The JEN! Editor Contact us Dr Stephanie Wood 01986 782368 [email protected] [email protected] Feedmark Ltd, Church Farm, St Cross South Contributors Elmham, Harleston, Norfolk, IP20 0NY With special thanks to Professor Jo-Anne Murray, Dr. Simon Daniels, and Abigail Malone. Whilst every care has been taken in compiling this publication The JEN shall not be made liable for any inaccuracies therein. Production & Design The opinions expressed in this publication are not necessarily Penny Church those of the Editor/Publisher. [email protected] 2 3Welcome Welcome to the Journal for Equine Nutrition, or as arrivals and the clip clop of tiny hooves. Talking of hooves, we like to call it, the JEN! We have developed the JEN Abigail also provides information on the key nutrients for so we can help you to do what you do best, provide your strong healthy hoof development in the article Nutrition for horses, ponies and donkeys with the best care. We believe hoof health. in helping you develop your knowledge and understanding The final section is a Research Roundup which of equine nutrition, health, and feed science, so you can highlights the key points from the 10th European Equine make the most appropriate decisions for the animals in Health & Nutrition Congress, which took place virtually your care. The JEN will include articles from our own this year. As part of Feedmark’s commitment to developing team of nutritionists and from equine specialists working products based on science and that align with the research in industry and in the fields of academia, research, and and academic communities’ views on equine health and veterinary science. nutrition, it was important for myself and our Senior Nutritionist to attend this congress. We not only heard the This first issue contains an overview of equine latest research, but were also part of a number of discussion gastrointestinal anatomy and function by Professor Jo- sessions on developing feedstuffs to support a forage-based Anne Murray from the University of Glasgow, which RE diet, forage options for different horses, trace element provides the foundation of understanding how we should PA sources and supply, and managing grass intake. To find feed and manage our horses. This is followed by a very P D out more see Research Roundup: Highlights from the 10th timely article on the feeding value of grass by Dr Simon ELC European Equine Health & Nutrition Congress. Daniels from the Royal Agricultural University. Dr Daniels YC picks apart why we need to account for the nutritional value E On behalf of the Feedmark team, I hope you enjoy R of grass in our horse’s diet. This is followed by an article I % reading the JEN and find the information useful. Further 00 have written on options for managing grass intake, which 1 issues will be published periodically throughout the year again is timely as the grass is now growing. The next article N and will be available digitally and in print. O opens up the subject of Boswellia, a very popular herb DE that has beneficial properties that we can use to support TNI our horse’s health and performance. Feedmark’s Senior RP Nutritionist, Abigail Malone, then outlines nutritional and dietary considerations for broodmares during foaling and Dr Stephanie Wood lactation, a very important article for those expecting new Editor Contents 4 24 Your horse’s gut: Nutrition of the mare gastrointestinal structure and function during foaling and lactation 7 31 Fuel or filler? Nutrition for hoof health What is the real nutrient content of grass for horses? 36 11 Research Roundup: Highlights from the 10th European Managing our horse’s grass intake Equine Health & Nutrition Congress 18 39 Ingredient Spotlight: Boswellia Glossary 2 3Your horse’s gut: gastrointestinal structure and function Professor Jo-Anne Murray, PhD, MSc, PgDip, PgCert, BSc (Hons), BHSII, RNutr, PFHEA, FRSB University of Glasgow Your horse’s gut plays such an important role in similar to the pre-caecal digestive system of a monogastric maintaining health and wellbeing. The gastrointestinal tract animal, such as the dog, man or pig. The second section, works hard digesting feedstuffs, making essential nutrients the hindgut, is more like the rumen of a cow. The stomach that the horse cannot produce on its own, protecting your of the horse contributes only eight percent to the total horse from disease, and even shaping the behaviour of digestive tract weight, with a capacity of approximately your horse. Thus, it is vital to maintain gut health and to eight litres in a mature 500kg horse. The small intestine ensure you are managing your horse in a way that promotes is comprised of three functional regions: the duodenum, gut health, through an understanding of the anatomy and the jejunum and the ileum, which together account for physiology of the equine gastrointestinal tract. around 30% of the total tract mass, but 75% of its total length. The large intestine consists of the caecum, and the OVERVIEW OF THE GASTROINTESTINAL TRACT large and small colons. The large intestine makes up 60% The horse is classified anatomically as a non-ruminant of the gastrointestinal tract volume and is proportionally herbivore and has a digestive tract that consists of three the largest hindgut of any domestic animal. The hindgut functional regions; the stomach and the small intestine, of the horse is anatomically specialised to accommodate collectively termed the foregut, and the large intestine, often micro-organisms capable of degrading and fermenting the referred to as the hindgut. The first section, the foregut, is structural polysaccharides (fibrous fraction) of plants. Professor Jo-Anne Murray, PhD, MSc, PgDip, PgCert, BSc (Hons), BHSII, RNutr, PFHEA, FRSB Professor Jo-Anne Murray has a PhD in Equine Nutrition, a MSc in e-learning, a PgDip in Animal Nutrition, a PgCert in University Teaching, and a degree in Equine Science. She is Principal Fellow of the Higher Education Academy, Registered Nutritionist with the Association for Nutrition and Fellow of the Royal Society of Biology. Jo-Anne has a record of outstanding achievement in leading education. Jo-Anne led the highly acclaimed MOOC in Equine Nutrition, with over 70,000 participants from across the globe. Jo-Anne also led the first online distance learning programme in Animal Nutrition. Jo-Anne has a dual portfolio of research in animal nutrition and education. Her nutrition work is focused on: (i) improving diet digestibility; (ii) the role of diet on the gut microbiome; (iii) the gut-brain axis; and (iv) the role of supplements/feed processing on gut health, the microbiome and behaviour. Jo-Anne has established collaborations with industrial and academic partners in the UK and internationally. Jo-Anne’s education research has evaluated MOOCs, mobile apps and virtual worlds. She has also evaluated horse owners’ feeding practices/knowledge of nutrition and veterinarians’ perceptions/knowledge of nutrition. She has published over 130 peer reviewed articles, numerous lay articles/blogs, is a journal editor (Animal) and reviewer, and invited speaker. 4 5THE FOREGUT of this part of the stomach is susceptible to damage if the The digestive process begins in the mouth. The incisor pH reduces and becomes acidic, which can result in gastric teeth (n=12) bite the vegetation selected by the upper lip. ulcers forming. The lower part of the stomach has a much The pre-molar (n=12) and molar teeth (n=12) then grind the lower pH (between 1.5 and 2) and the lining of this area is food to facilitate a reduction in particle size, whilst mixing protected by a mucous layer. There is evidence to show that it with saliva secreted as a direct response to chewing. horses left for longer than 3 hours without access to forage Saliva appears to have little or no digestive enzyme activity are at greater risk of developing gastric ulcers. Horses in the horse, unlike many other species (Frape, 2010). fed large amounts of cereal grains, which take less time to However, its mucus content allows it to act as a lubricant for the passage of the feed bolus down the oesophagus into the stomach, via a process known as peristalsis, and its inorganic salt content enables it to act as a buffer to the acidic conditions present in the stomach. Chewing is such an important aspect of digestion as a) the reduction in feed particle size improves the digestibility of the nutrients in the feed and b) horses only produce saliva as a direct result R of chewing and therefore if the horse is not chewing then EPA no saliva is being produced, which can impact on the health P D of your horse’s stomach. Horses chew four times as much, EL Figure 2. Fibrous foods are essential in the equine diet as they require with a two-fold increase in saliva production, when eating CY more chewing which stimulates secretion of saliva that buffers the acidic C forages compared to when eating concentrates (Meyer et stomach and helps to protect against gastric ulcers. ER al., 1985). %00 chew, and lower amounts of forage, are also much more 1 N likely to develop gastric ulcers. In fact, reports suggest O D that as many as 85% of racehorses may have gastric ulcers ET (Begg & O’Sullivan, 2003). In addition, exercise can also NIR impact on this as there can be ‘splashing’ of acidic contents P from the lower part of the stomach to the sensitive upper part of the stomach, resulting in the formation of ulcers. Digesta leaving the stomach enters the small intestine where it is mixed with intestinal secretions that maintain a neutral environment (pH 7) and break down fats, proteins and non-structural carbohydrates (starch and sugars). There are a few important things to be aware of in terms of the small intestine; firstly, only the protein digested here Figure 1. The average horse’s gastrointestinal tract is 30m long with an enlarged hindgut developed to process a high fibre diet is of direct benefit to the horse, any undigested protein travels to the hindgut and is used as a substrate by the microbiota (bacteria, fungi and protozoa, also referred to The stomach of the horse has two main areas; the upper as microbes). Secondly, the horse has a limited capacity part referred to as the non-glandular region, and the lower for starch digestion and any starch not digested in the small part referred to as the glandular region. The upper part of intestine will also travel to the hindgut where it will be the stomach relies on the saliva swallowed with the food, fermented by the microbes. Moreover, cereal grains (oats, to maintain a neutral pH of between 6 and 7. The lining 4 5barley, maize) need to be processed in some way otherwise fermented by microbes in the hindgut as the horse lacks the endogenous enzymes required to digest these plant the starch present in these grains is less digestible in the constituents. In fact, the hindgut is designed to digest fibre small intestine. Finally, the horse does not produce enzymes and it is when non-fibrous substrates, such as starch and to break down fructan in the small intestine. Fructan is a fructan, enter the hindgut that problems can arise. The by- non-structural carbohydrate (NSC) present in grass, and products of this fermentation process are the volatile fatty since this cannot be digested in the small intestine it travels acids (VFA) acetate, propionate and butyrate, and the gases to the hindgut and is used as a substrate by the microbes. carbon dioxide (CO2) and methane (CH4). The VFAs are High levels of starch and/or fructan entering the hindgut then absorbed across the gut wall and are used as an energy of the horse can disrupt the hindgut environment and elicit source by the horse (Hintz et al., 1971). The microbial the onset of various disorders, such as hindgut acidosis, populations in your horse’s gut are incredibly sensitive laminitis and colic (Bailey et al., 2004). Consequently, to change. Any change in diet or management can have it is recommended that no more than 1g starch per kg a significant impact on microbial populations, which can bodyweight is fed per meal (Harris & Dunnett, 2018), lead to a disturbance in the gastrointestinal tract and an which, for a 500kg horse, is no more than 500g or 0.5kg increased risk of colic (Garber et al., 2020). Therefore, it is of starch per meal. In practical terms, if concentrate feed important to make any changes to the diet gradually to help contains 25% starch then no more than 2kg of that feed maintain gastrointestinal health. should be fed per meal. SUMMARY THE HINDGUT • Feed a high-fibre diet, with a forage-first approach In contrast to the small intestine, the mucosa of the and then add in any additional feedstuffs only where large intestine contains only mucus-secreting glands that required. do not produce any digestive enzymes. Instead, digestion • Only if required, feed high-starch concentrate feeds and absorption in the hindgut is dependent on microbial little and often and avoid large bucket feeds of starchy fermentation of undigested feed residues leaving the small foodstuffs. intestine. It is only in recent years that we have begun • Make any changes to the diet gradually over a period to understand more about the microbes that reside in our of two weeks. horse’s gut. Bacteria, protozoa and fungi all inhabit the horse’s gut, but bacteria appear to be present in the largest • Maintain a healthy weight and condition in your numbers and have been the primary focus of most research horse(s) and monitor on a regular basis. studies looking at gut microbes in horses. ement changes gradually, e.g. amount • Make any manag of time in the stable or at pasture. Structural carbohydrates, i.e. those within the plant cell wall (fibrous fraction of the plant – see Fuel or filler? • the use of supplements that can help maintain Consider What is the real nutrient content of grass for horses?), are gastrointestinal health. REFERENCES Bailey, S.R., Marr, C.M., & Elliott, J. (2004). Current research and theories on the pathogenesis of actute laminitis in the horse. Equine Veterinary Journal, 167: 129-142. doi:10.1016/S1090-0233(03)00120-5 Begg, L.M., & O’Sullivan, C.B. (2003). The prevalence and distribution of gastric ulceration in 345 racehorses. Australian Veterinary Journal, 81(4): 199-201. doi.org/10.1111/j.1751-0813.2003.tb11469.x Frape, D. (2010). Equine Nutrition and Feeding, 4th Ed. Wiley-Blackwell, UK. Garber, A., Hastie, P., & Murray, J.-A. (2020). Factors influencing equine gut microbiota: current knowledge. Journal of Equine Veterinary Science, 88: 102943. doi: 10.1016/j.jevs.2020.102943 Harris, P., & Dunnett, C. (2018). Nutritional tips for veterinarians. Equine Veterinary Education, 30 (9): 486-496. doi.org/10.1111/eve.12657 Hintz, H.F., Argenzio, R.A., & Schryver, H.F. (1971). Digestion coefficients, blood glucose levels and molar percentage of volatile acids in intestinal fluid of ponies fed varying forage-grain ratios. Journal of Animal Science, 33(5): 992-995. doi: 10.2527/jas1971.335992x Meyer, H., Coenen, M., & Gurer, C. (1985). Investigations of saliva production and chewing in horses fed various feeds. Proceedings of the Nineth Equine Nutrition and Physiology Society, East Lansing, Michigan, UK: 38-41. 6 7Fuel or filler? What is the real nutrient content of grass for horses? Dr. Simon Daniels, PhD, PgCert, BSc (Hons), SFHEA, R.Anim.Sci, Senior Lecturer at Royal Agricultural University As horse managers we are aware that time at grass than we need, we store excess either as glycogen in our is important for our equine companions. Grass turnout muscles and liver, or as fat. Well plants have a similar allows horses to demonstrate natural behaviours, be that of mechanism whereby they store additional sugars produced trickle feeding or social interaction. But how many horse via photosynthesis as water soluble carbohydrates (WSC), managers really consider the nutrient content of the grass which includes glucose, fructose, sucrose and fructans their horses are eating? I still come across people referring (Undersander, 2013). Fructans are a storage molecule, to fibre as “bulk” or “filler” without considering it as a a mammalian example would be glycogen whereby we source of nutrients. convert glucose to a storage molecule to save it until we need it, then we transfer it back to glucose to metabolise PLANT NUTRIENTS it when we need it. Within the plant excess simple R In the spring the environmental conditions are generally EP sugars e.g. glucose and fructose, are joined together by A ideal for grass to start growing. There is moisture in the P beta (β) glycosidic bonds to form fructan. Water soluble D ground from the winter, the air temperature is increasing EL carbohydrates are stored within the stem of the plant as C which warms the soil and the hours of daylight start to Y reserves for times when the plant is not producing enough CE lengthen. Plants convert sunlight into soluble carbohydrates, R sugar for growth. Fructan cannot be digested in the small % these sugars are the energy source the plant uses for growth 0 intestine because mammals do not possess the enzymes 01 and they are also the energy sources our horses metabolise needed to break the β glycosidic bonds that link the NO into useful energy (McDonald et al., 2011). We are all glucose and fructose molecules together. Lots of fructans DE aware that in mammals when we eat more carbohydrates entering the large intestine can be problematic to the TNIRP Dr Simon Daniels, PhD, PgCert, BSc (Hons), SFHEA, R.Anim.Sci Simon is a Senior lecturer at the Royal Agricultural University in Equine Science. Simon studied Equine and Animal Science at the University of Lincoln, after graduating he worked for a horse feed manufacturer as part of the nutrition team before moving on to work for the University of Liverpool on a parasitology project within the School of Veterinary Medicine. Simon went on to complete a PhD in equine anthelmintics, efficacy and effects on intestinal health with Prof Chris Proudman at the University of Surrey School of Veterinary Medicine and Science. Simon has been lecturing in higher education since 2012, and joined the RAU in 2014. Simon’s research interests remain within equine gastrointestinal health and disease including both parasitology and nutrition and their effect on normal gut function. Gut health is directly influenced by diet and nutrition and therefore Simon is also interested in the management of grasslands and how both fresh and conserved forage can influence gut heath. 6 7matures and lignin increases, the digestibility decreases horse (Ince et al., 2013), as fructans are readily fermented (Cuddeford, 1996). by bacteria in the horse’s hindgut, specifically by “sugar loving” saccharolytic bacteria (Shirazi-Beechey, 2008). Fibre is formed by joining β glucose molecules together, Fructan is converted into a volatile fatty acid (VFA) that similar to forming fructans, but in this case in much longer feeds into the glucose pathway, but it is also converted into chains forming the structural carbohydrate cellulose lactate. The production of significant amounts of lactate (McDonald et al., 2011). To digest fibre we need to break decreases the pH in the horse’s hindgut ecosystem, altering the glycosidic bonds between these β glucose molecules the conditions which the fibre loving bacteria that reside to be able to make use of these carbohydrates. However, here need to survive (Daly et al., 2012) (see Your horse’s mammals do not possess the enzymes, principally cellulase, gut: gastrointestinal structure and function for more needed to break down the bonds in the β glucose molecules information on the equine digestive tract and importance of which form cellulose, in the same way that they cannot the hindgut). Practically we see this on a scale, from horses digest fructan (Frape, 2010). However, microbiota that producing loose droppings at the subtle end of the scale, reside in the horse’s hindgut and in the rumen of cows and to colic and laminitis at the severe end, and thus stability sheep, do produce cellulase, meaning these microbiota can of microbiota in the horse’s hindgut is essential for horse break down fibre through fermentation. The younger the health. This is why we avoid grazing laminitic animals plant is in the growth cycle the more fibre can be digested when fructan in the grass is likely to be high. (Cuddeford, 1996). Of the cell wall contents the most digestible component is hemicellulose. Other digestible As the growing season continues the grass continues to fibre sources are pectins which are found between two plant grow and the leaves become more mature. We are all aware cells and act as glue to stick cells together. that fresh spring leaves tend to flop to the ground but if we leave grass to grow e.g. for hay, then as it matures it stands Plant protein is found inside the plant cells, and is made upright. As the plant matures the cell wall increases in up of sequences of amino acids. Some amino acids can be thickness to give the plant structure (Cuddeford, 1996). We synthesised within the body (termed non-essential amino acids) but others must be sourced within the diet (termed essential amino acids) and are essential nutrients for normal body function. Lysine is an essential amino acid that is also the first limiting amino acid, meaning it is the first to become deficient. Therefore, when considering protein content in the diet we have to consider if we can meet the horse’s amino acid requirements from our grass. The next consideration for protein within grass is the digestibility, as the horse can only make use of protein that is digested and absorbed within the small intestine (Frape, 2010). As Figure 1. Plant cells under magnification, showing the insoluble, fibrous the plant matures and the cell wall becomes more lignified cell wall (dark green outline) and soluble inner cell contents then the amount of protein digestion in the small intestine is reduced. In more mature lignified grass the protein is refer to this cell wall as structural carbohydrates, which are liberated from the plant cells in the horse’s hindgut where the elements of the plant which make up the fibre content. billions of microbiota ferment the plant material. However Fibre is essential for the horse’s diet and fibre digestibility protein that is digested in the hindgut is not bioavailable to is also influenced by the grass growth cycle as not all fibres the horse, instead the microbiota make use of this protein are digestible. The plant cell wall which allows the plant to themselves. So as the growing season progresses the protein stand tall is made of lignin which is found in all plants but digestibility of mature grass within the horse decreases. unfortunately it cannot be digested, therefore as the plant 8 9The crude protein (CP) content varies by season, being The fat content of grass is limited, but fat is present approximately 300g/kg DM in the spring, 100-140g/kg consisting of waxes and includes essential omega-3 fatty DM in the summer, 140-200g/kg DM in the autumn and acids. The vitamin and mineral content will be influenced less than 100g/kg DM in the winter. Applying this to the by the soil and the management of the grass, but much of scenario above, in theory the crude protein requirement the major mineral requirement of horses should be covered would be met all year. However this does not factor in by grass (Cuddeford, 1996). protein quality, availability, digestibility in the small NUTRIENT REQUIREMENTS OF HORSES intestine nor the amino acid profile. Working to the If initially we assume the nutrient requirements at digestibility profile above (60%), when there is less than maintenance for a mature 500 kg animal are approximately 120g/kg of CP available in the grass and the grass is 70 mega joules (Mj) of digestible energy (DE) per day, a mature, we are unlikely to meet the daily requirement of breakdown of the key nutrient requirements can be seen in our scenario animal as a proportion of this protein will table 1 below. be degraded in the hindgut. Equally, the digestibility will decrease as the plant matures as the protein become less Table 1. Key nutrient requirements of a 500kg horse at maintenance bioavailable. Minerals and trace minerals in well managed Nutrient 500kg Horse grass should meet the nutrient requirements with possible slight deficiencies in copper and selenium by 2 and 0.5 mg/ DE (Mj) 69.68 REP kg respectively, but this will depend on the individual CP (g) 630 AP soil profile. D Lys (g) 27 EL PASTURE SUITABILITY C Ca (g) 20 YC So theoretically we should be able to meet the E P (g) 14 R maintenance nutrient requirement of horses from pasture %0 Na (g) 10 alone, although this will depend on the individual animal’s 01 requirements. If we consider a Thoroughbred racehorse N Cl (g) 40 O then the nutrient requirement will be much higher than that D K (g) 25 ET of a native pony type, even at maintenance. We also need to DE: Digestible energy, CP: Crude protein, Lys: Lysine, Ca: Calcium, NI P: Phosphorus, Na: Sodium, Cl: Chloride, K: Potassium. R consider how we manage our grass as agricultural practices P for cattle often produce grass with too much WSC for our The energy content of grass will obviously be variable horses (Longland, 2012). Sometimes horse managers can depending on time of year, weather conditions, location, be guilty of neglecting pastures and they become “horse and management, but for meadow pasture the DE content sick” (Figure 2). It is important that we manage our grass to is approximately 8-10 Mj/kg on a dry matter (DM) basis. avoid this. Many of the weeds flourish because the grass is However, some ryegrasses with high water soluble content over grazed, not fertilised and the soil pH is not optimum. can be up to 14 Mj/kg DM. We generally assume that on a Many horse managers worry about using fertiliser on their dry matter basis that horses at pasture full time will eat over grass as they do not want excess grass growth. However, 15 hours around 1kg of dry matter per hour. We work to the the grass plants need both phosphorus and potassium for basis that grass is roughly 20% dry matter and therefore the good root development. If the roots are deep and well fresh matter intake of grass per day will be considerably developed, they will seek water and nutrients from further greater as we allow for the moisture content. Working on into the ground, helping the plants become resilient to those assumptions, the average 500kg horse can consume “horse traffic”. Shallow rooted plants will not thrive and it 135 Mj on the basis of eating 15kg dry matter. On the is easier for poaching to occur, therefore it is important to assumption that the digestibility of good pasture is around feed the roots with a fertiliser appropriate for your pasture 60%, on average we exceed the daily energy requirement. type and requirements. 8 9Over grazing grass down to very fine stubble also causes weight per day in dry matter, in comparison to horses who the plant stress. To aid recovery the plant will store more at maximum can eat 3% of their body weight per day in WSC e.g. fructans which help it recover. This can be dry matter. Going back to cows briefly, a dairy cow needs problematic for weight management and animals prone to approximately 62 Mj of energy a day for maintenance, yet laminitis (Watts, 2010). This is the same at times of drought for milk production she needs three times that for a low and frost, and is the reason why you may have come across milk yield, or five and a half times that for a high yield. advice not to graze frosty grass. So our cob type, needing approximately 70 Mj DE per day for maintenance and grazing 5% of its body weight in dry matter, can consume four times its daily maintenance energy requirement per day. This is why grazing designed for cattle does not work for horses, especially good doers and ponies, and it is easy to see how they can become obese by eating four times their maintenance energy requirement per day! Another management problem with native types is they are designed to store reserves for the winter, therefore they gain weight in the summer to lose in the winter. However the use of rugs, feeding concentrates and stabling mean that these native types and good doers just continually gain weight. Figure 2. Allowing fields to be extensively grazed enables weeds to take over and the pasture to become ‘horse sick’, reducing its value as a feed TAKE HOME MESSAGE source There is huge potential in our grass, however sometimes Often with horses we have grazing extremes, either it can under deliver on essential minerals and nutrients such poorly managed grasslands that become horse sick, or as protein, and over supply energy contributing to equine grasses that are managed for agricultural purposes e.g. obesity. It is really important that we manage our grass for cattle. High productivity cows are often managed on high horses, so we can have healthy pasture and healthy horses. WSC pastures to ensure plenty of energy is available for Making use of mineral licks/supplements or balancers can growth or milk production. These pastures tend to be be a way of ensuring you provide the protein and minerals unsuitable for horses who do not need high WSC diets. without providing additional calories, and as for weight The problems are greatest with our ponies and cob types management of horses, well that is a whole other topic which have been recorded eating up to 5% of their body in itself! REFERENCES Bott, R.C., Greene, E.A., Koch, K., Martinson, K.L., Siciliano, P.D., Williams, C., Trottier, N.L., Burk, A., & Swinker, A. (2013). Production and Environmental Implications of Equine Grazing. Journal of Equine Veterinary Science. 33: 1031-1043. doi.org/10.1016/j.jevs.2013.05.004 Cuddeford, D. (1996). Equine Nutrition. The Crowood Press Ltd. Daly, K., Proudman, C. J., Duncan, S.H., Flint, H.J., Dyer, J., & Shirazi-Beechey, S. (2012). Alterations in microbiota and fermentation products in equine large intestine in response to dietary variation and intestinal disease. British Journal of Nutrition, 107(7): 989-995. doi:10.1017/S0007114511003825 Frape, D. (2010). Equine Nutrition and Feeding, 4th Ed. Wiley-Blackwell, UK. Ince, J.C., Longland, A.C., Moore-Colyer, M.J.S., & Harris, P.A. (2013). In vitro degradation of grass fructan by equid gastrointestinal digesta. Grass and Forage Science, 69(3): 514-523. https://doi.org/10.1111/gfs.12061 Longland, A.C. (2012). Nutritional assessment of forage quality. In: Saastamoinen M., Fradinho M.J., Santos A.S., Miraglia N. (eds) Forages and grazing in horse nutrition, vol 132. Wageningen Academic Publishers, Wageningen. McDonald, P., Edwards, R.A., Greenhalgh, J.D.F., Morgan, C.A., Sinclair, L.A. & Wilkinson, R.G. (2011). Animal Nutrition, 7th Ed. Pearson Education Ltd. Shirazi-Beechey, S.P. (2008). Molecular insights into dietary induced colic in the horse. Equine Veterinary Journal, 40(4): 414-421. doi:10.2746/042516408X314075 Undersander, D. (2013). Grass Varieties for Horses. Journal of Equine Veterinary Science, 33: 315-320. doi.org/10.1016/j.jevs.2013.03.008 Watts, K. (2010). Pasture management to minimise the risk of equine laminitis. Veterinary Clinics of North America: Equine Practice, 26(2): 361-369. doi.org/10.1016/j.cveq.2010.04.007 10 11Managing our horse’s grass intake Dr. Stephanie Wood, PhD Equine Nutrition, PgDip, BSc (Hons), RNutr (Animal), R.Anim.Tech As you might expect, the amount of time our horses taken at a certain point in time, so may not be applicable spend in the field varies with the seasons, with more to all parts of your pasture or to grass at a different growth horses living out in summer as the days get longer and the stage (Martinson et al., 2017). Despite these limitations, weather and ground conditions improve, and more horses testing for nutrient content is advised as it is better than not being completely stabled in winter primarily to avoid fields having any information on the grass your horse is eating. becoming poached (Ireland et al., 2011). Regardless of the Determining how much grass your horse eats when turned time of year, most owners report giving their horses daily out is the other challenge making it difficult to account for access to pasture, even if only for a few hours (Ireland et al., grass intake in your horse’s diet. In the research setting, 2011; Wylie et al., 2013). Time in the field allows horses to measuring the amount of grass before horses graze and move freely, interact with their surroundings, interact with then again after grazing, enables estimates of how much other horses visually if in separate fields, and physically if grass is consumed (Martinson et al., 2017). This method RE they can touch, and to perform grazing behaviour that is is relatively straight forward but is only an estimate due PA so important to them for maintaining mental and physical to sampling small sections of grass, meaning variations in P D health (see Your horse’s gut: gastrointestinal structure and grass cover are not accounted for. This method also does ELC function). As discussed in the article Fuel or filler? What not account for the selective grazing behaviour of horses YC is the real nutrient content of grass for horses? time in who will eat certain plant species and completely ignore ER the field also supplies nutrients and should be accounted others (Archer, 1973). It is also only suitable for estimating %00 for when developing and managing your horse’s diet. intake over a short period of time (hours) as it does not 1 N Accounting for the energy (calories), protein, fatty acids, account for grass growth over the grazing period. O D vitamins, and minerals horses obtain from grass is not E A more accurate estimate of grass intake can be gained T always the primary consideration by owners, as it is easy NI from information on the digestibility (amount of nutrients R to view the field as a place where horses exercise and enjoy P absorbed by the animal) of the grass consumed and the time being a horse, and not as a self-service buffet. Not amount of faeces produced. Markers are used to gain accounting for grass as a source of nutrients and energy can such information, and are substances that are indigestible lead to horses consuming an unbalanced diet that affects to the horse, meaning they can be tested for in the faeces their condition, health and performance. (Dove & Mayes, 1991; Martinson et al., 2017). The use of markers is generally more accurate than measuring grass Accounting for the grass our horses consume is not before and after grazing, however it is only suitable for use straight forward. Energy and nutrient content change with in the research setting due to the requirement for chemical grass stage of growth, and determining how much your markers and laboratory equipment. horse eats when in the field is particularly challenging. The only real way of knowing the nutrient content of the Due to the difficulties in determining our horses’ grass specific grass your horse is eating is to analyse for its intake, and the potential for grass to trigger laminitis in nutrient content. Commercial premises producing high some equids, we need practical methods to account for value horses are more likely to undertake grass nutrient energy and nutrients gained from grass. We also need analysis, although analysis of grazing for horses is still not practical methods to manage grass intake, whether this is common practice. One potential reason for limited testing limiting the amount of grass consumed for those animals of grass is that the results gained are specific to the sample prone to laminitis, insulin dysregulation and weight gain, 10 11or optimising grass intake for growing animals and those vitamins and minerals) or a balancer (vitamins, minerals needing to gain weight. For healthy horses, the easiest and protein source), as these are low in starch and sugars way of accounting for grass intake in the diet is to monitor and can be fed either on their own if pelleted, or with a their weight and fat stores. Monitoring body weight and fat small amount of chaff if powdered. stores by regularly weigh taping and fat scoring your horses LIMITING GRASS INTAKE is straight forward, quick and non-invasive, and indicates Many owners find they need to limit the amount of grass if more or less energy is required (Figure 1). If all other their horse or pony consumes due to them being prone parts of your horse’s diet, exercise and management remain to weight gain or susceptible to metabolic issues such as the same and they are gaining weight then they must be laminitis or insulin dysregulation. How best to control gaining more energy from the grass, and vice versa if they the amount of grass your horse eats will depend on the are losing weight. You can then review your horse’s diet to facilities available to you and the amount of flexibility you identify what changes are needed to enable them continued have using those facilities. The main methods of limiting access to the field whilst keeping them at a healthy body grass intake are; weight. Reviewing the diet as a whole (grass, preserved 1. reduce the amount of time with access to grass 2. reduce the amount of grass your horse has access to 3. reduce your horse’ s ability to consume the grass 1) Reduce the amount of time with access to grass: Reducing the amount of time your horse has access to grass requires them to spend more time in an alternative environment. For many owners the only other place they can keep their horses is in the stable. Ideally, we want to reduce the stabling period as it reduces their physical movement and time they can interact with other horses, increases their exposure to stable dust which can negatively impact respiratory health (Hotchkiss, 2019), and increases bedding and forage costs. There are times when horses have to be stabled rather than out in the field, e.g. due to ill-health, injury, or to reduce exposure to biting midges Figure 1. Regularly assessing your horse’s weight and fat stores and flies that irritate the skin, but we would ideally not is important for determining if their diet or management requires stable them for extended periods of time to just reduce adjustment, with weigh tapes offering an easy way of estimating body weight grass intake. An alternative is to provide access to a dry lot, or fenced area with an alternative ground surface. Such forage, concentrate feeds and supplements) is important as setups prevent grazing whilst allowing movement, social fat scoring does not account for intake of other nutrients, interaction, and fresh air. If using such a setup, access to although it does provide an indication of the potential water and shelter are still required and it is recommended nutritional quality of your grass. Ideally you want to utilise to provide a form of low energy preserved forage so horses the grass as a nutrient source and minimise the amount can continue trickle feeding but without consuming too of concentrate feed you are providing as this will help to many calories. maintain gastrointestinal and mental health, and is one of the Reducing time in the field may not always lead to cheapest forms of feed available. One of the easiest ways of reduced grass intake. The amount of grass consumed, ensuring your horse is receiving all the nutrients it requires measured as dry matter intake (DMI), is a result of bite rate is to feed a vitamin and mineral supplement (concentrated 12 13(number of bites per minute) and bite size (amount of grass to 8-, 12- and 23-hours grazing access ate similar amounts per bite), with these factors being influenced by animal of grass as there was no benefit to donkeys grazing for size and the amount of grass available (Fleurance et al., longer due to such sparse pasture. When grass availability 2009). Equids respond to variations in grass availability increased the donkeys with 23-hours access were at an by increasing or decreasing these bite parameters, with advantage, able to consume more than those with 12- or a balance being required to maintain DMI. When ample 8-hours grazing (Wood et al., 2012). Such results do not grass is available larger bites can be taken, however these mean that restricting time in the field is unsuitable for require more chewing and can result in a lower bite rate, limiting grass intake, but they do show that the effect of whereas when grass availability is limited, smaller, more grazing time on your horse’s intake may not be easy to frequent bites can be taken (Naujeck & Hill, 2003; Edouard predict and will be affected by the amount of grass available et al., 2009). As bite rate increases, selectivity decreases, and your individual horse’s response. When the amount of meaning that when food resources are limited equids have grass available is limited, bite size and bite rate can only a feeding strategy of maintaining DM and energy intake, increase by so much, meaning that in these circumstances rather than selecting for higher nutrient plants (Friend & they cannot compensate for reduced time at grass, leading Nash, 2000; Wood et al., 2012). This feeding strategy leads to a lower DMI from grass whilst allowing all the benefits to variations in individual nutrient intakes and their balance of time in the field previously discussed. R within the diet. E Overnight grazing PAP When limiting grazing time studies have shown that Another option available to owners is to allow access DE horses, ponies, and donkeys increase bite rate and/or bite to pasture overnight and to stable or keep horses on dry LC size, leading to a faster DMI. Ince et al. (2011) restricted lots during the day. Equids graze less intensively overnight YCE ponies to 3-hours grazing per day over a 6-week period (Doreau et al., 1980; Wood, 2010) so only turning out R % and found that the amounts of grass consumed increased overnight may help to reduce intake and is more suitable 001 over the six weeks, with ponies consuming almost double for some animals affected by biting insects or sunburn. The N the amount they consumed at the start of the study. These amount of grass available should still be considered in these O D results indicate that the ponies became accustomed to the circumstances as some equids will adapt to a night grazing ETN management routine and short grazing time, increasing routine and simply eat an equivalent amount as they would IRP their intake rate to maximise the amount of grass they could during the day. eat. Similar results were reported by Glunk et al. (2013) 2) Reduce the amount of grass your horse has access to: restricting mature horses to either 3-, 6-, 9- or 24-hours An alternative to restricting the amount of time your grazing. These authors found that intake rate increased horse has access to grass is to influence the amount of with decreasing grazing time, being fastest when horses grass. Shorter grass tends to have lower herbage mass had three hours grazing time and slowest when they had (g DM/hectare) than taller grass, however taller grass is 24-hour access to grass. This faster DMI allows equids more fibrous and of lower nutritional value, meaning there to compensate for shorter grazing periods, potentially is no simple answer to what length grass is optimum for neutralising any effect of reduced grazing time, although horses. The height of grass has been shown to influence bite this is dependent on the amount of grass available. In the parameters, and therefore grass intake, by horses, ponies study by Glunk et al. (2013), the amount of grass available and donkeys. When grazing shorter grass, smaller, more prevented horses compensating for the shorter grazing frequent bites that require less chewing are utilised, allowing times, leading to significantly less grass being eaten when equivalent amounts to be consumed as when grazing restricted to six hours grazing or less, compared to when taller grass (McMeniman, 2003; Fleurance et al., 2010). allowed 24 hours access. In a study using donkeys where Increased time spent grazing combined with increased bite grass availability was extremely limited, donkeys restricted rate can compensate for shorter grass, meaning that limiting 12 13one, or both, of these compensatory options (grazing time Strip grazing or grass height) has the potential for reducing grass intake. Controlling the amount of fresh, ungrazed pasture your Harrison & Murray (2016) found that limiting ponies to horse accesses daily using strip grazing is a practical option very short grass (1-2cm) did effectively limit the amount of for many owners, being relatively quick, simple and cheap grass they could consume, however having such short grass to setup using electric fencing. Strip grazing using a single may damage the pasture and underlying soil structure. Increased stocking density Increasing the number of animals on the grass is another option for decreasing herbage mass per animal (g DM/ animal), although there are a number of factors to consider before choosing this option. With an increased number of equids in a field there will be increased competition for food, water and shelter resources. The increased competition for food is positive if wanting to reduce grass intake, however increased competition for water and shelter will increase animal interactions and potentially the risk of injury (Owen et al., 2012). You also need to ensure that there are no harmful plants, such as ragwort or bracken, that could be consumed if horses become hungry and seek alternative food sources. The effect on pasture quality should also be considered, as over-grazing can cause weeds to proliferate and takeover. Increased weeds are also seen in areas where horses defecate, leading to a greater proportion of the field being left ungrazed due to weeds and toilet areas, which also reduce pasture quality. A final consideration is the increased potential for parasite transmission between animals. Reducing parasite burdens require the life cycle of the parasite to be broken (Corbett et al., 2014; Rendle et al., 2019). This is achieved by identifying infected animals and providing effective treatment, and by removing faeces from the pasture, which can be difficult when large numbers of equids are in the same field. Grazing with non-equine species such as sheep, overcomes some of these issues whilst reducing herbage mass per animal. Sheep and horses tend to graze different parts of the field, resulting in a more uniform pasture. Figure 2. Options for strip grazing equids. Setup A uses a single, lead Sheep and horses are also less likely to cause injury to each fence. Setup B uses a lead fence and a back fence to maintain the same size grazing area. other, however fencing required to keep sheep in the field is usually not safe for horses due to the risk of their legs moving fence (Figure 2, Setup A) limits the amount of becoming caught. Grazing with sheep also increases the ungrazed grass your horse can eat, however the total grazing risk of liver fluke in equines (Howell et al., 2020) therefore area increases in size over time. As animals preferentially it is important to assess and manage this risk. graze the fresh grass, the grass in the remainder of the field 14 15has opportunity to grow. This can lead to the beneficial reduce this sudden rapid intake. What was very positive in effects of strip grazing being reduced as the overall herbage the study by Longland et al. (2021) is that both methods of mass per animal increases. Strip grazing using two fences strip grazing lead to ponies maintaining a relatively stable (Figure 2, Setup B) has a lead fence that moves to allow body weight over the study period compared to ponies with access to fresh, ungrazed grass, and a back fence that is access to the whole grazing area who gained weight and moved the same distance as the lead fence, that keeps the increased fat stores. Such results show that strip grazing grazing area size the same. Using two fences not only helps is a useful option for limiting grass intake whilst allowing to control herbage mass per animal, but also enables areas access to the field. of the field to be rested without having to remove animals 3) Reduce your horse’s ability to consume the grass: from the area completely. Reducing your horse’s ability to consume grass can be achieved by using grazing muzzles (Figure 3). Various Over a 28-day period, Longland et al. (2021) studied muzzle designs are available, all aiming to reduce your the effect of strip grazing on grass intake by ponies with horse’s bite size, although many equids also seem less 23-hours access to grass. The study compared the effect motivated to graze when they are wearing a grazing of strip grazing using a single lead fence (setup A), strip muzzle, suggesting that the effort required to eat may not be grazing using a lead and a back fence (setup B), and no worth the small amount of grass gained. The effectiveness strip grazing where ponies had access to a grazing area RE of grazing muzzles on reducing grass intake ranged from of equivalent size and herbage mass. Ponies consumed PAP 83% in ponies grazing over a 3-hour period (Longland et significantly less grass when managed using the strip DE al., 2011) to 30% in horses grazing over a 4-hour period grazing systems compared to those with no strip grazing, LC (Glunk et al., 2014). The differences between these figures Y despite the same overall grazing area. The lowest intakes CE reflects the differences in methods used to estimate intakes were recorded for ponies managed with a lead and back R % and differences in grass height. In the study by Longland fence due to them having a smaller grazing area and lower 001 et al. (2011) the ponies were grazing grass 8-15cm tall, herbage mass per animal. In the first two weeks of the study N whereas in the study by Glunk et al. (2014) the grass was O the ponies in the strip grazing groups grazed all parts of the DE fresh grass, leaving very little ungrazed grass. This indicated TNI they were not selectively grazing and were focusing on RP consuming whatever fresh grass they could access. This was opposite to the ponies with access to the whole pasture area who selectively grazed, most likely at a slower rate. A concern by some owners is that horses, ponies, and donkeys managed using strip grazing, excessively gorge on the fresh grass once access is provided. Such a concern is valid as sudden intakes of fresh, lush grass can lead to gastrointestinal upset. Research by Dowler et al. (2012) Figure 3. Muzzles are one option for limiting the amount of grass horses who limited adult horses to 8-hours grazing per day and can consume whilst allowing them time in the field monitored grass DMI over this period, found that the rate of grass intake was greatest (almost double) in the first four 15-20cm tall. It is thought that grass that is too short cannot hours of grazing than in the second four hours of grazing. If reach through grazing muzzles, leaving animals frustrated utilising strip grazing, it is worth considering when to allow and likely to dig up short pastures in an attempt to eat access to the fresh pasture. If practical, offering fresh grass something. In contrast, grass that is too long can be difficult after animals have already been grazing for several hours, to sever and chew when wearing muzzles, potentially or overnight if managed with 24-hour grazing, may help to reducing intake. The form of the grass can also influence the 14 15effectiveness of muzzles. Grasses that grow upright easily OPTIMISING GRASS INTAKE poke through the muzzle giving the animal something to The phrase ‘Doctor Green’ relates to the nutrients eat, whereas grasses that have a wider growth pattern are grass can supply to our horses and the beneficial effects of not as easily accessible. Muzzles seem most appropriate these nutrients. As discussed in Fuel or filler? What is the for use when grass is 3-20cm tall, although this will vary real nutrient content of grass for horses? grass can be an with grass species and your individual horse, pony or excellent source of nutrients, and for some horses, is the donkey’s response. food that makes them look and feel at their best. For these animals, the main aim is optimising intake and balancing All of these factors need considering when deciding the diet. whether to use grazing muzzles. They can certainly help to reduce grass intake however they should not be left on Optimising intake is about correct pasture management. all day, and therefore horses may simply compensate for Ensuring there is adequate herbage mass per animal and reduced intake due to being muzzled, by eating rapidly appropriate grass species for the type of animal, type of when unmuzzled (Longland et al., 2016; Davis et al., soil and weather conditions is important. Discussing your 2020). Such compensatory responses indicate that grazing specific requirements with an agronomist with an interest muzzles are helpful in managing grass intake if used in equine pastures is the best option for achieving a suitable alongside other practices, such as limiting grazing time or pasture that will have longevity. More immediate actions strip grazing. you can take are to ensure you provide appropriate shelter from inclement weather and the sun. Flies and midges are Animals must be acclimatised to wearing muzzles and also deterred from entering dark areas so a shaded area will checks made that they know how to drink otherwise they help to reduce irritation from biting insects. Clean, fresh risk dehydration. Some animals refuse to drink whilst water with enough access space for multiple horses at once wearing muzzles which is one reason they should not is also essential. be worn 24-hours a day. As previously mentioned, some equids are reluctant to even try to graze when wearing One of the most important actions you can take is to a muzzle and spend their time just standing in the field. create a clean grazing area by regularly removing faeces Whilst this is preferable to standing in a stable, long periods from the field. This has multiple benefits, including of time without consuming any food are not advised. increasing grazing area per animal, breaking the parasite Dr Stephanie Wood, PhD, PgDip, BSc (Hons), RNutr (Animal), R.Anim.Tech Stephanie has many years’ experience managing horses in both a private and professional capacity. During her time caring for different horses she developed a keen interest in nutrition which lead her to gain her undergraduate degree in Equine Science from Aberystwyth University, followed by a PhD in Equine Nutrition from the Royal (Dick) School of Veterinary Studies at the University of Edinburgh. These academic achievements are recognised in her certifications as a Registered Animal Nutritionist and Registered Animal Technologist. Stephanie has a passion for helping others to learn and understand which was utilised in her positions as Senior Equine Technologist where she developed training and educational material for the equine industry, and as Senior Lecturer where she tutored the next generation of equine professionals. Stephanie’s passion for helping others combined with her hands-on industry experience and technical knowledge enable her to support owners with practical advice and guidance in her role as Director of Science and Nutrition at Feedmark. 16 17individual animal’s requirements. For some equids this life cycle, reducing weed development and not attracting flies. It is important that collected faeces are removed from may mean reducing time in the field and increasing time in the field and not piled in the field corner as this simply a dry lot, arena, or stable, whilst for others a grazing muzzle concentrates the issues of flies, parasites, and weeds in one is the perfect tool for limiting grass intake. For those who place. By creating a pleasant environment for your animals seem to blossom when Doctor Green is here then providing to graze they are more likely to be settled and enjoy being clean, hygienic grass should be the focus. When not in the field, taking their time to forage and exhibit their grazing, providing a suitable preserved forage will enable natural grazing behaviour. trickle feeding to continue and optimise gastrointestinal and mental health. A vitamin and mineral supplement or SUMMARY balancer further supports health and ensures optimum Grass is an extremely useful resource for most equids so long as the amount consumed is managed to match the nutrient intake. REFERENCES Archer, M. (1973). The species preferences of grazing horses. Journal of the British Grassland Society, 28: 123-128. doi.org/10.1111/j.1365-2494.1973. tb00732.x Corbett, C.J., Love, S., Moore, A., Burden, F.A., Matthews, J.B., & Denwood, M.J. (2014). The effectiveness of faecal removal methods of pasture management to control the cyathostomin burden of donkeys. Parasite & Vectors, 7:48. doi:10.1186/1756-3305-7-48 Davis, K.M., Iwaniuk, M.E., Dennis, R.L., Harris, P.A., & Burk, A.O. (2020). Effects of grazing muzzles on behavior and physiological stress of individually housed grazing miniature horses. Applied Animal Behaviour Science, 231: 105067. doi.org/10.1016/j.applanim.2020.105067 RE Doreau, M., Martin-Rosset, W., & Petit, D. (1980). Activités alimentaires nocturnes du cheval au pâturage. Annales de Zootechnique, 29: 299-304. P Dove, H., & Mayes, R.W. (1991). The use of plant wax alkanes as marker substances in studies of the nutrition of herbivores: A review. Australian AP Journal of Agricultural Research, 42: 913-952. doi.org/10.1071/AR9910913 Dowler, L.E., Siciliano, P.D., Pratt-Phillips, S.E., & Poore, M. (2012). Determination of Pasture Dry Matter Intake Rates in Different Seasons and DE Their Application in Grazing Management. Journal of Equine Veterinary Science, 32: 85-92. doi:10.1016/j.jevs.2011.06.006 L Edouard, N., Fleurance, G., Dumont, B., Baumont, R., & Duncan, P. (2009). Does sward height affect feeding patch choice and voluntary intake in CY horses? Applied Animal Behaviour Science, 119:219-228. doi:10.1016/j.applanim.2009.03.017 C Fleurance, G., Duncan, P., Fritz, H., Gordon, I.J., & Grenier-Loustalot, M.-F. (2010). Influence of sward structure on daily intake and foraging ER behaviour by horses. Animal, 4: 480-485. doi:10.1017/S1751731109991133 Fleurance, G., Fritz, H., Duncan, P., Gordon, I.J., Edouard, N., & Vial, C. (2009). Instantaneous intake rate in horses of different body sizes: influence %0 of sward biomass and fibrousness. Applied Animal Behaviour Science, 117: 84-92. doi.org/10.1016/j.applanim.2008.11.006 01 Friend, M.A., & Nash, D. (2000). Pasture intake by grazing horses. Canberra, Australia, Rural Industries Research & Development Corporation. Glunk, E.C., Pratt-Phillips, S.E., & Siciliano, P.D. (2013). Effect of Restricted Pasture Access on Pasture Dry Matter Intake Rate, Dietary Energy NO Intake, and Fecal pH in Horses. Journal of Equine Veterinary Science, 39: 421-426. doi.org/10.1016/j.jevs.2012.07.014 Glunk, E.C., Sheaffer, C.C., Hathaway, M.R., & Martinson, K.L. (2014). Interaction of Grazing Muzzle Use and Grass Species on Forage Intake of DE Horses. Journal of Equine Veterinary Science, 34: 930-933. doi.org/10.1016/j.jevs.2014.04.004 T Harrison, R., & Murray, J.M.D. (2016). A preliminary study of grazing intakes of ponies with and without a history of laminitis. Livestock Science, NI 186: 2-5. doi.org/10.1016/j.livsci.2015.08.012 RP Hotchkiss, J.W. (2019). Equine asthma: managing the environment. UK-Vet Equine, 3(3). doi.org/10.12968/ukve.2019.3.3.78 Howell, A.K., Malalana, F., Beesley, N.J., Hodgkinson, J.E., Rhodes, H., Sekiya, M., Archer, D., Clough, H.E., Gilmore, P., & Williams, D.J.L. (2020). Fasciola hepatica in UK horses. Equine Veterinary Journal, 52: 194-199. doi: 10.1111/evj.13149 Ince, J., Longland, A.C., Newbold, J.C., & Harris, P.A. (2011). Changes in proportions of dry matter intakes by ponies with access to pasture and haylage for 3 and 20 hours per day respectively, for six weeks. Journal of Equine Veterinary Science, 31: 283. doi.org/10.1016/j.jevs.2011.03.106 Ireland, J.L., Clegg, P.D., McGowan, C.M., McKane, S.A., & Pinchbeck, G.L. (2011). A cross-sectional study of geriatric horses in the United Kingdom. Part 1: Demographics and management practices. Equine Veterinary Journal, 43(1): 30-36. doi:10.1111/j.2042-3306.2010.00145.x Longland, A.C., Barfoot, C., & Harris, P.A. (2011). The effect of wearing a grazing muzzle vs not wearing a grazing muzzle on pasture dry matter intake by ponies. Journal of Equine Veterinary Science, 31 (5-6): 282–283. doi.org/10.1016/j.jevs.2011.03.105 Longland, A.C., Barfoot, C., & Harris, P.A. (2016). Efficacy of Wearing Grazing Muzzles for 10 Hours per Day on Controlling Bodyweight in Pastured Ponies. Journal of Equine Veterinary Science, 45: 22-27. doi.org/10.1016/j.jevs.2016.04.015 Longland, A.C., Barfoot, C., & Harris, P.A. (2021). Strip-grazing: Reduces pony dry matter intakes and changes in bodyweight and morphometrics. Equine Veterinary Journal, 00: 1–8. doi: 10.1111/evj.13416 Martinson, K.L., Siciliano, P.D., Sheaffer, C.C., McIntosh, B.M., Swinker, A.M., & Williams, C.A. (2017). A Review of Equine Grazing Research Methodologies. Journal of Equine Veterinary Science, 51: 92-104. doi.org/10.1016/j.jevs.2017.01.002 McMeniman, N.P. (2003). Pasture intake by young horses. Canberra, Australia, Rural Industries Research & Development Corporation. Naujeck, A., & Hill, J. (2003). Influence of sward height on bite dimensions of horses. Animal Science, 77: 95-100. doi:10.1017/S1357729800053698 Owen, K.R., Singer, E.R., Clegg, P.D., Ireland, J.L., & Pinchbeck, G.L. (2012). Identification of risk factors for traumatic injury in the general horse population of north-west England, Midlands and north Wales. Equine Veterinary Journal, 387: 143-148. doi:10.1111/j.2042-3306.2011.00387.x Rendle, D., Austin, C., Bowen, M., Cameron, I., Furtado, T., Hodgkinson, J., McGorum, B., & Matthews, J. (2019). Equine de-worming: a consensus on current best practice. UK-Vet Equine, 3(1): 1-14. doi.org/10.12968/ukve.2019.3.S.3 Wood, S.J. (2010). Some factors affecting the digestible energy requirements and dry matter intake of mature donkeys and a comparison with normal husbandry practices (PhD Thesis). Retrieved from http://hdl.handle.net/1842/4817 Wood, S.J., Smith, D.G., Morris, C.J., & Cuddeford, D. (2012). The effect of pasture restriction on dry matter intake of foraging donkeys in the United Kingdom. In: Saastamoinen M., Fradinho M.J., Santos A.S., Miraglia N. (eds) Forages and grazing in horse nutrition, vol 132. Wageningen Academic Publishers, Wageningen. doi.org/10.3920/978-90-8686-755-4_17 Wylie, C.E., Ireland, J.L., Collins, S.N., Verheyen, K.L.P., & Newton, J.R. (2013). Demographics and management practices of horses and ponies in Great Britain: A cross-sectional study. Research in Veterinary Science, 95: 410-417. doi.org/10.1016/j.rvsc.2013.05.004 16 17Ingredient Spotlight: Boswellia Dr. Stephanie Wood, PhD Equine Nutrition, PgDip, BSc (Hons), RNutr (Animal), R.Anim.Tech The use of plants for medicinal purposes stretches back BOSWELLIA THE BOTANIC since records began, predominantly focusing on human Boswellia is one genus within the Burseraceae family health, but over recent years there has been growing interest of plants. Within the Boswellia genus there are 28 species in how certain plants can support animal health. One such names currently accepted (WFO, 2021), although there are plant is Boswellia, which is now extremely popular with names that are synonymous with accepted names, which horse owners and is available on its own and incorporated can lead to confusion on what species are available or into formulated products. This popular ingredient triggers included in products (Table 1). Boswellia species are native to tropical America, Africa and Asia, with specific species grown in specific locations (Daly et al., 2011; Iram et al., 2017). Table 1. Organisation of key Boswellia species Family Burseraceae Genera Boswellia Species of B. serrata B. sacra Flueck interest (Frankincense) B. balsamifera Spreng. Figure 1. Boswellia serrata tree that produces resin (insert) within B. carteri Birdw. B. glabra Roxb. its trunk and branches which is harvested for its anti-inflammatory B. bhaw-dajiana properties B. thurifera Synonymous Birdw. Roxb. ex names B. Fleming. extensive debate amongst owners, primarily focusing on undulatocrenata Chloroxylon (Engl.) Engl. the level of boswellic acids. This debate is valid since dupada Buch.- Ham. boswellic acids are the components of the plant that have been shown to have health benefitting properties (Ammon, America Yemen 2010; Daly et al., 2011; Roy et al., 2019; Al-Harrasi et al., Origins India Oman 2021), however it is not the only consideration. Here at Somalia India Feedmark we openly acknowledge that the research to date has not provided a minimum boswellic acid requirement The reference to Boswellia serrata that is commonly for humans or animals, or a recommended boswellic acid cited in equine information and product pages relates to a level, and therefore we should not focus solely on the level specific Boswellia species found in India, and which can of boswellic acids in products. Boswellic acid profile, be correctly referred to as Indian Frankincense (Figure feeding level and feeding form are important factors that 1). However, the terms Boswellia serrata and Indian also need to be considered when wanting our horses to Frankincense are often mistakenly used as a generic term benefit from Boswellia. 18 19for all Boswellia species, most likely due to Boswellia BOSWELLIC ACIDS serrata being the most abundant of Boswellia species and As already highlighted, medicinal properties have been the one that seems to be harvested the most for its resin, attributed to boswellic acids, however research has shown and not because it is superior compared to other Boswellia that certain boswellic acids have greater effect than others species. Boswellia sacra, also known as Boswellia carteri, (Roy et al., 2019), hence the need to consider the boswellic is a lesser known Boswellia species that has been shown to acid profile. Research has identified multiple types of contain high levels of boswellic acids and have the same boswellic acids in Boswellia resins, with up to 12 acids medicinal properties as the more well-known Boswellia being identified within the resin of Boswellia serrata and serrata (Daly et al., 2011; Mannino et al., 2016). Boswellia carteri species (Al-Harrasi et al., 2018; Roy et al., 2019). Six of these boswellic acids have been identified Plants in the Boswellia genus are generally in the form as the main acids associated with inhibiting the enzymes of trees and shrubs which have canals within their trunk involved in inflammation, although the different acids and branch structures. Within these canals is resin, also vary in their contribution to the total boswellic acid referred to as oleo-gum resin, or simply gum-resin (Daly content (Table 2). et al., 2011). The resin is harvested from the Boswellia trees by either slicing or boring into the bark, then dried Table 2. Contribution of boswellic acids to the total boswellic R and processed for use in products. The species from acid content in resin from Boswellia serrata and Boswellia carteri EP associated with inhibiting inflammation A which the resin originates influences its composition and P D Boswellic acid appearance, which can range from clear to milky in colour E Contribution towards L (abbreviation shown in C and from watery to gum-like in consistency (Daly et al., boswellic acid content Y brackets) CE 2011). Reports on the composition of Boswellia resins R α-boswellic acid (BA) % vary, with the lipophilic parts (fat-loving compounds that 10 - 21% 00 β-boswellic acid (BA) 1 dissolve or combine well with fat) of the resin being the N Acetylated α-boswellic O most important as these are rich in terpenoids (Al-Harrasi acid (ABA) D 0.05 - 6% E et al., 2018). Al-Harrasi et al. (2018) report that resin from T Acetylated β-boswellic NI Boswellia carteri grown in Oman and in its natural state, acid (ABA) RP contained 55-65% lipophilic compounds, whilst Mannino 11-keto-β-boswellic acid 2.5 - 7.5% (KBA) et al. (2016) found total lipophilic compounds averaged 3-O-acetyl-11-keto-β- 55% in Boswellia serrata and 60% in Boswellia carteri. 0.1 - 3% boswellic acid (AKBA) So you may be wondering what terpenoids are and why they are important. They are important because boswellic In vitro (laboratory based) research indicates that KBA acids comprise of terpenoids, specifically pentacyclic and AKBA are the most potent and effective boswellic triterpene molecules, and boswellic acids have been shown acids at down-regulating inflammatory enzymes, thought to have medicinally important qualities and so can be to be due to the presence of the 11-keto group (Roy et thought of as the active part of triterpenes within Boswellia al., 2019). However, some studies indicate that boswellic resin. However, the lipophilic part of Boswellia resin is acids are relatively poorly absorbed and metabolised by the not all boswellic acids as it contains other terpenes such body. The potential limited absorption of boswellic acids as mono-, di- and other triterpenes, not just the pentacyclic is something that is not acknowledged or discussed, yet it forms found in boswellic acids. Therefore, any products is paramount, as having high levels of boswellic acids in reporting just the lipophilic component of Boswellia resin a product means very little if those acids are not absorbed by the animal. In vitro studies into the ability of boswellic will be overestimating boswellic acid levels. 18 19acids to cross a simulated intestinal wall are inconclusive, to consumption of the acids alone (Sterk et al., 2004). with some studies finding low permeability for AKBA, Such findings offer potential for increasing boswellic acid and moderate permeability for a Boswellia serrata extract absorption in horses as the feeding of fat in the equine diet (Krϋger et al., 2009), whilst another in vitro study found is relatively common and is easily achieved. Piperine, a both KBA and AKBA were very permeable (Gerbeth et compound found in Black Pepper (Piper nigrum L.) and al., 2013). The variability in these results shows more Long Pepper (Piper longum L.), has been shown to improve research is required to determine the ability of boswellic boswellic acid absorption in rabbits, and so offers another acids to cross the intestinal wall, and raises the question; potential method of increasing boswellic acid utilisation can boswellic acid absorption be increased in any way? (Vijayarani et al., 2020), although further research is needed to determine the true picture of boswellic acid absorption in horses. Until such research takes place, we should focus WHAT ARE TERPENOIDS/TERPENES? on using the most effective sources of boswellic acids and • Terpenoids are constituents of essential oils and are feeding appropriate amounts. mostly organic compounds consisting of only carbon PHYSIOLOGICAL ACTIONS OF BOSWELLIC ACID and hydrogen elements (hydrocarbons). Despite the lack of research to demonstrate the beneficial • The building blocks of terpenoids are 5-carbon effects of Boswellia in horses, there is a demand for Boswellia isoprene units which have a formula containing 5 equine products, indicating that owners are seeing benefits to carbons and 8 hydrogens, or C5H8 [CH2=C(CH3)- feeding this herb. These benefits are mainly due to the anti- CH+CH2]. inflammatory and immune-supporting actions of Boswellia which have been demonstrated in laboratory studies, human • Terpene hydrocarbons have the formula (C5H8)n, trials (Sengupta et al., 2008) and in dogs (Reichling et al., with the n dictating how many units of isoprene are 2004). General literature states that boswellic acids can involved. modulate enzymes involved in the inflammatory process, • Terpene hydrocarbons are classified according to the namely growth factors, kinases, and transcription factors number of isoprene units: (Ammon, 2010; Roy et al., 2019). Literature also promotes 2 isoprene units = 10 carbons Monoterpenes = that boswellic acids can stimulate apoptosis (cell death), Sesquiterpenes = 3 isoprene units = 15 carbons which has focused research in humans on the anti-cancer Diterpenes = 4 isoprene units = 20 carbons effects of Boswellia. Cancers are relatively rare in equids 6 isopr 30 carb Triterpenes = ene units = ons compared to other conditions therefore Boswellia is not fed 8 isoprene units = 40 carbons Tetraterpenes = for this reason, however the anti-inflammatory properties • Triterpenes are further classified, with pentacyclic of Boswellia make it an attractive ingredient for supporting triterpenes being one of these groups. joint function (Figure 2). Joint issues and mobility support Osteoarthritis is the most common joint issue affecting The lipophilic nature of boswellic acids limits their humans, horses and dogs (Carmona & Prades, 2009). solubility in water but increases their ability to combine with The condition is characterised by progressive cartilage fats, therefore it was hypothesised that feeding the acids deterioration, subchondral bone remodelling (changes to the alongside fat could increase their absorption. Research in bone under the cartilage), loss of joint space, development of humans indicates that administering boswellic acids orally bony projections or spurs (osteophytosis) and pain, leading with a meal containing fat increases absorption of the acids, based on a greater increase in plasma boswellic acid to reduced function and mobility (Schlueter & Orth, 2004). levels after consumption with a fat-based meal compared Regardless of the cause of osteoarthritis, the condition is 20 21Table 3. Key molecules involved in osteoarthritis in equids associated with inflammation caused by proinflammatory substances which induce degradation of cartilage and the Key molecules involved in inflammation and physiological changes described previously. osteoarthritis in equids Interleukin -1 (IL-1) At the molecular level, osteoarthritis results from an IL-1β imbalance of substances that promote synthesis of the Catabolic cytokines IL-6 extracellular matrix (ECM) of articular cartilage, and Tumor necrosis factor-α substances that induce remodelling of these components (TNF-α) (Table 3) (Schlueter & Orth, 2004; Carmona & Prades, Matrix 2009). To counteract normal degradation (catabolism) of metalloproteinases (MMPs) tissue, the body also produces anabolic molecules which Extracellular matrix Serine proteases degrading enzymes function to counteract this degradation and promote growth Aspartic proteases or repair of tissues. Anabolic molecules are produced Cysteine proteases to counteract the catabolic effects of joint wear and Prostaglandins E2 osteoarthritis however the effects of the catabolic molecules (PGE2) Eicosanoids tend to dominate (Schlueter & Orth, 2004; Carmona & Leukotrienes R Prades, 2009). E Inflammatory mediator Nitric oxide PAP Key anabolic molecules associated with D osteoarthritis in equids ELC IGF-1 Insulin-like growth YC factors E IGF-2 R Transforming growth factor-β (TGF-β) %001 NO used in a double-blind, randomised placebo-controlled Figure 2. The anti-inflammatory properties of boswellic acids are DE beneficial for supporting mobility and joint function trial. TNIR Boswellia extracts and boswellic acids inhibit • P Research into the effects of Boswellic acids on the synthesis of leukotrienes which are key pro- inflammation associated with osteoarthritis has shown that inflammatory molecules, with the presence of the 11- they can inhibit and stimulate various molecules. Several of keto group thought to be a requirement for this inhibitory these studies are highlighted below: action (Roy et al., 2019), explaining the greater effects • Extracts of specific boswellic acids, AKBA and seen with KBA and AKBA. This inhibitory action acetyl α-boswellic acid, inhibited the generation of is due to boswellic acids inhibiting 5-lipoxygenase proinflammatory TNFα in vitro, with AKBA being the (5-LOX), the key enzyme in leukotriene synthesis most active component (Syrovets et al., 2005). (Siemoneit et al., 2009). However, these results were gained in vitro along with results that indicated that • Boswellia extract containing 30% AKBA (5-Loxin®) albumin cancels out this inhibitory effect, as albumin prevented TNFα induced expression of MMPs in vitro binds to 11-keto-boswellic acids. Albumin is a key using human cells (Roy et al., 2005). The same extract component of blood therefore boswellic acids may has also been shown to reduce knee pain and improve not be effective in reducing leukotriene synthesis due function within seven days in humans suffering from osteoarthritis who were administered a daily oral dose to being bound to albumin once absorbed. Further research is required to confirm such findings. of 100mg and 250mg (Sengupta et al., 2008) when 20 21The inhibitory effect of boswellic acids on leukotrienes • A study feeding a Boswellia serrata extract containing >50% triterpenes (actual boswellic acid levels not is also associated with the respiratory supporting qualities disclosed) at a dose of 400mg extract/10kg body of Boswellia (Ammon, 2010). Leukotrienes are known weight, to 29 dogs with inflammatory joint and spinal to induce bronchoconstriction and mucus secretion disease, found that clinical signs greatly improved (Ammon, 2010) which reduce respiratory efficiency and over a 6-week period (Reichling et al., 2004). No make breathing even harder for those with sensitivities to pharmacological tests were performed so there certain particles such as dust or pollens. Scientific studies was no data on absorption or possible modes of to support the use of Boswellia for respiratory health in action, however clinical assessment of lameness and animals are lacking however the lack of studies indicating movement by a veterinary professional indicated much any negatives of giving respiratory sensitive animals improvement in the dogs. Boswellia indicates it is safe to feed for such issues. Gastric, respiratory and immune support SUMMARY Boswellic acids have been shown to increase antibody Boswellia is a herb with many qualities that are beneficial production when administered at low doses (25mg/kg BW) to mice, giving them an immunostimulatory action to our horses, with its anti-inflammatory action offering at low doses (Ammon, 2010). However, when given at the most potential for a range of issues. This review has higher doses (50-200mg/kg BW) this effect is thought to be highlighted that the boswellic acid profile, boswellic reversed, having an immune-depressing action (Ammon, acid level and mode of feeding should all be considered, 2010; Roy et al., 2019). Such effects could be deleterious with the feeding of fat and Piperine offering potential to depending on the situation, for example conditions caused increase absorption. The feeding of Boswellia extracts is by over activity of the immune system could be perpetuated one option for providing the important boswellic acids, if low doses of boswellic acids are given, whereas feeding however there is no recommended minimum boswellic a similarly low dose to rundown horses could stimulate acid level. Feeding 20g of a dried boswellia resin which immunity with beneficial effects. For these reasons it is contains 35% boswellic acids provides more boswellic important to discuss your horse’s requirements, and the acids than feeding 10g of a boswellia extract containing potential for Boswellia to support your horse, with your vet 65% boswellic acids, and unless stated the boswellic acid if they have immune related issues. profile is unlikely to be known. Use of products that have Boswellic acids are also promoted for their a high percentage of total boswellic acids and specifically gastroprotective and calming properties and are proposed AKBA, the most potent inflammatory inhibiting boswellic as support for inflammatory bowel disease and diarrhoea acid, will provide excellent support to your horses, although (Ammon, 2010; Roy et al., 2019). Studies in rats show such concentrated boswellic acids are more costly, meaning that boswellic acids have an antispasmodic action which the decision as to which form of boswellia you feed has calms the digestive tract, reduces motility leading to a slowing of digesta passage and reduced diarrhoea (Borrelli another factor to consider. et al., 2006). In addition, boswellic acids are thought to There is criticism about the lack of supporting research protect against gastric ulcers in rats due to their inhibitory for herbal supplements, however we believe owners know effect on 5-LOX, thus inhibiting the synthesis of pro- their horses the best and can make informed decisions on inflammatory leukotrienes (Ammon, 2010). This link has what works for their horses. Boswellia resin and Boswellia not been established in horses but certainly warrants further extracts do have research supporting their actions, although investigation due to the prevalence of gastric ulcers in we would always like studies conducted on horses. horses, particularly performance horses. 22 23REFERENCES Al-Harrasi, A., Khan, A.L., Rehman, N.U., & Csuk, R. (2021). Biosynthetic diversity in triterpene cyclization within the Boswellia genus. Phytochemistry, 184: 112660. doi.org/10.1016/j.phytochem.2021.112660 Al-Harrasi, A., Rehman, N.U., Khan, A.L., Al-Broumi, M., Al-Amri, I., Hussain, J., Hussain, H., & Csuk, R. (2018). Chemical, molecular and structural studies of Boswellia species: β-Boswellic Aldehyde and 3-epi-11β-Dihydroxy BA as precursors in biosynthesis of boswellic acids. PLoS ONE, 13(6): e0198666. doi.org/10.1371/journal.pone.0198666 Ammon, H.P.T. (2010). Modulation of the immune system by Boswellia serrata extracts and boswellic acids. Phytomedicine, 17: 862-867. doi:10.1016/j.phymed.2010.03.003 Borrelli, F., Capasso, F., Capasso, R., Ascione, V., Aviello, G., Longo, R., & Izzo, A.A. (2006). Effect of Boswellia serrata on intestinal motility in rodents: inhibition of diarrhoea without constipation. British Journal of Pharmacology, 148(4): 553-560. doi:10.1038/sj.bjp.0706740 Carmona, J., & Prades, M. (2009). Pathophysiology of Osteoarthritis. Compendium Equine, January/February: 28-39. Daly, D.C., Harley, M.M., Martínez-Habibe, M.-C., & Weeks, A. (2011). Burseraceae. In: Kubitzki, K. (ed) The Families and Genera of Vascular Plants ,Volume X Flowering Plant Eudicots. Springer, Berlin, Germany. Gerbeth, K., Hϋsch, J., Fricker, G., Werz, O., Schubert-Zsilavecz, M., & Abdel-Tawab, M. (2013). In vitro metabolism, permeation, and brain availability of six major boswellic acids from Boswellia serrata gum resins. Fitoterapia, 84: 99-106. doi.org/10.1016/j.fitote.2012.10.009 Iram, F., Khan, S.A., & Husain, A. (2017). Phytochemistry and potential therapeutic actions of Boswellic acids: A mini-review. Asian Pacific Journal of Tropical Biomedicine, 7(6): 513-523. doi.org/10.1016/j.apjtb.2017.05.001 Krüger, P., Kanzer, J., Hummel, J., Fricker, G., Schubert-Zsilavecz, M., & Abdel-Tawab, M. (2006). Permeation of Boswellia extract in the Caco-2 model and possible interactions of its constituents KBA and AKBA with OATP1B3 and MRP2. European Journal of Pharmaceutical Sciences, 36(2- 3): 275-284. doi:10.1016/j.ejps.2008.10.005 Mannino, G., Occhipinti, A., & Maffei, M.E. (2016). Quantitative Determination of 3-O-Acetyl-11-Keto--Boswellic Acid (AKBA) and Other Boswellic Acids in Boswellia sacra Flueck (syn. B. carteri Birdw) and Boswellia serrata Roxb. Molecules, 21(10): 1329. doi.org/10.3390/molecules21101329 Reichling, J., Schmökel, H., Fitzi, J., Bucher, S., & Saller, R. (2004). Dietary support with Boswellia resin in canine inflammatory joint and spinal disease. Schweiz Arch Tierheilkd, 146(2): 71-79. doi: 10.1024/0036-7281.146.2.71 Roy, N,K., Parama, D., Banik, K., Bordoloi, D., Devi, A.K., Thakur, K.K., Padmavathi, G., Shakibaei, M., Fan, L., Sethi, G., Kunnumakkara, A.B. RE (2019). An Update on Pharmacological Potential of Boswellic Acids against Chronic Diseases. International Journal of Molecular Science, 20 (17): P 4101. doi.org/10.3390/ijms20174101 AP Roy, S., Khanna, S., Shah, H., Rink, C., Phillips, C., Preuss, H., Subbaraju, V.G., Trimurtulu, G., Krishnaraju, A.V., Bagchi, M., Bagchi, D., & Sen, D C.K. (2005). Human Genome Screen to Identify the Genetic Basis of the Anti-inflammatory Effects of Boswellia in Microvascular Endothelial Cells. EL DNA and Cell Biology, 24(4): 244-255. C Schlueter, A.E., & Orth, M.W. (2004). Equine osteoarthritis: a brief review of the disease and its causes. Equine and Comparative Exercise Physiology, YC 1(4): 221-231. doi:10.1079/ECEP200428 E Sengupta, K., Alluri, K.V., Satish, A.R., Mishra, S., Golakoti, T., Sarma, K.V.S., Dey, D., & Raychaudhuri, S.P. (2008). A double blind, randomized, R placebo controlled study of the efficacy and safety of 5-Loxin® for treatment of osteoarthritis of the knee. Arthritis Research & Therapy, 10(4): R85. %0 doi.org/10.1186/ar2461 01 Siemoneit, U., Pergola, C., Jazzar, B., Northoff, H., Skarke, C., Jauch, J., & Werz, O. (2009). On the interference of boswellic acids with 5-lipoxygenase: N Mechanistic studies in vitro and pharmacological relevance. European Journal of Pharmacology, 606: 246-254. doi:10.1016/j.ejphar.2009.01.044 O Sterk, V., Büchele, B., & Simmet, T. (2004). Effect of food intake on the bioavailability of boswellic acids from a herbal preparation in healthy D volunteers. Planta Med, 70(12): 1155-1160. doi: 10.1055/s-2004-835844 ET Syrovets, T., Büchele, B., Krauss, C., Laumonnier, Y., & Simmet, T. (2005). Acetyl-Boswellic Acids Inhibit Lipopolysaccharide-Mediated TNF-α NI Induction in Monocytes by Direct Interaction with IκB Kinases. The Journal of Immunology, 174(1): 498-506. doi.org/10.4049/jimmunol.174.1.498 R Vijayarani, K.R., Govindarajulu, M., Ramesh, S., Alturki, M., Majrashi, M., Fujihashi, A., Almaghrabi, M., Kirubakaran, N., Ren, J., Babu, R.J., Smith, P F., Moore, T., & Dhanasekaran, M. (2020). Enhanced Bioavailability of Boswellic Acid by Piper longum: A Computational and Pharmacokinetic Study. Frontiers in Pharmacology, 11: 551911. doi:10.3389/fphar.2020.551911 WFO (2021). World Flora Online: Boswellia. Published on the Internet; http://www.worldfloraonline.org. Accessed 29 March 2021. Do YOU have anything you would like our Scientists to research? If you have any specific topics that you would like us to feature in The JEN, please email us at: [email protected] 22 23Nutrition of the mare during foaling and lactation Abigail Malone, BSc month that it is due. For example, a foal that is expected to It can be a nerve-racking time when breeding horses, have a racing career is likely to be due earlier in the foaling with many management and nutritional factors to consider season than a sport or leisure horse, as those with racing along the way. Factors generic to all broodmares and their careers begin training much sooner and so will be more foals need to be considered in the context of the individual developed if they are born earlier. Some more commercial animal’s requirements to allow appropriate decisions to be broodmares may have a foal every year, making the first made that support the health and welfare needs of the mare month after having the previous foal incredibly crucial to and her foal. set her up within a short time period for her next pregnancy. The gestation period averages 340 days (11 months) Studies have shown that day length can affect foaling dates but can vary between 320 and 380 days (Satué et al., (Cilek, 2009) with longer gestation lengths decreasing 2011). Gestation length, and therefore foaling date is the possibility of mares coming back into oestrus within influenced by environmental, foetal, and most importantly the same covering season (Dicken et al., 2012). Although maternal factors (Satué et al., 2011). Environmental factors many breeders will know the due date of the foal, a vet can influencing gestation length include seasonal conditions help determine this more accurately using blood tests and or climate, the amount of sunlight the mare receives each scans, to ensure you are ready for the birth. day (also known as photoperiod), and when the mare was All of these factors must be considered when predicting mated within the season. Many studies including one by the date that the mare is due to foal and begin lactating. Cilek (2009) found that gestation length was significantly Feeding requirements are not only different as the pregnancy reduced when mares were mated at the end of the season and lactation period progresses (Lewis, 1995), but are also (July to November) compared to at the start (January dependent on the time of year and weather conditions as the and February). Foetal factors include genetics, the sex nutritional quality of grazing will vary (see Fuel or filler? of the foetus, and the type of pregnancy, with research What is the real nutrient content of grass for horses?) and showing that male foetuses tend to lead to slightly longer poor weather increases the mare’s energy requirements. pregnancies, whilst in the case of twins, if the pregnancy The mare can start lactating early, up to a month before is successful, the gestation period tends to be much shorter foaling, or wait until only a few hours before giving birth (Satué et al., 2011). Maternal factors such as nutritional before she produces any milk (Thomas, 2020). Lactation state, age, breed and number of births the broodmare has will continue until the foal is weaned or until approximately had, if any, will effect gestation length. Older mares may 6 months after giving birth. Lactation is a critical period have decreased nutritional efficiency of their uterus and in the mares breeding cycle as it is the most nutritionally placenta, meaning that gestation length is increased as the demanding period for the mare as she provides nutrients to growth process becomes slower (Wilsher & Allen, 2003), the growing foal (Lawrence, 2013). Milk yields can range and mares who receive optimal nutrition, rather than just a from 2 to 3% of the mare’s body weight per day, so for a maintenance diet, have been seen to have shorter gestation 500kg mare this equates to her producing 10-15 litres of lengths (Satué et al., 2011). milk daily. Such demands make it easy to understand why her nutritional needs are at maximum during the lactation What the foal is being bred for is likely to determine the 24 25period. Providing a diet that meets the mare’s nutrient and to differentiate between signs of labour and those of colic energy requirements will allow her to adequately nurse her (Chenier & Whitehead, 2009). Colic is common amongst foal whilst remaining healthy herself. heavily pregnant and newly birthed mares, therefore close monitoring of the mare is needed (Steel & Gibson, 2002). CONSIDERATIONS DURING FOALING Whilst foaling may be unexpected, many signs are clear Making the mare as comfortable as possible is key, so by and round the clock observations can ensure help can be keeping the mare in a regular routine and keeping her calm provided quickly if any problems occur. Many births occur leading up to, during, and immediately after the birth will during the evenings and early morning, although there is aid the chances of the mare’s survival and a safer delivery always the chance of a daytime birth (Dicken et al., 2012). of her foal. Maintaining her routine includes what she is Monitor the mare’s mammary gland for when she begins fed as sudden dietary changes can increase the risk of colic bagging up (Figure 1), which usually occurs two to three (Lawrence, 2013). Providing a feed that can be gradually weeks before foaling whilst waxing often appears in the increased in quantity when needed, rather than completely last few days of pregnancy (Thomas, 2020). Behavioural changing the feed type or brand, is preferable. The diet signs such as the mare seeming unsettled, restless, or should be palatable to encourage eating and optimise intake and based on an ample supply of suitable forage. REP The nutritional needs of the mare change throughout AP her gestation period as placental growth takes place during DEL early pregnancy and the final three to four months is when CY the majority of foetal growth takes place. From the fifth CER month of gestation onwards the mare’s energy and crude %0 protein requirements increase, therefore an increase in dry 01 matter intake (DMI) is likely needed (Lawrence, 2013). NO Kubiak et al. (1989) found that providing excess energy DE in late gestation did increase the mare's body weight and TNI condition but did not increase the foal's birth weight, RP however horses that have their late gestation period in the winter months may have increased energy requirements due to more energy being needed to maintain body temperature (Lawrence, 2013). Ideally the pregnant mare’s diet will contain 16% crude protein (CP), with a good supply of Lysine, the first limiting amino acid making it an essential amino acid. The Lysine requirement can be calculated by multiplying the CP requirement by 4.3%, therefore high- Figure 1. Mare with an enlarged udder, also known as ‘bagging up’, due quality protein must be provided in the diet (NRC, 2007). to the production of milk in preparation for birth of the foal Cereal grains are often low in essential amino acids and therefore provide low-quality forms of protein, whereas stressed, and abnormal movements can indicate labour high-quality protein can be found in feedstuffs such as Soya has begun. Defecating and urinating little and often, and bean meal, Brewer’s Yeast and Alfalfa. not wanting to eat as much as normal are further signs of Vitamin A and E requirements are higher than that for imminent labour, however these signs are similar to those maintenance throughout pregnancy whilst Calcium and exhibited by horses with colic, meaning it can be difficult 24 25Phosphorus needs increase a small amount in months 7-8 NUTRITIONAL REQUIREMENTS and larger amounts in months 9-11. Copper and Iodine The lactation period brings about the most sudden requirements also increase in months 9-11 but there are changes in nutrient requirements and this is when the no increased needs for Iron, Manganese, Zinc or Selenium broodmare’s nutritional needs increase the most. Providing (Lawrence, 2013). From this information it is easy to see the mare with optimum nutrition will enable her to produce why increasing a general vitamin and mineral supplement enough high-quality milk for her foal. In the first month could meet the increased requirements of certain nutrients, of lactation a 500kg mare will produce an estimated but oversupply other nutrients. Feed or supplements 16.3 litres per day of milk (Table 1), with this amount specifically designed for breeding animals is advised to reaching maximum when the foal reaches about 6 weeks ensure requirements are met in the correct balance. of age (NRC, 2007). After this period the amount of milk gradually reduces, coinciding with a slowing of the foal’s The addition of prebiotics and probiotics can be rate of growth (average daily gain in body weight measured helpful in supporting the normal function of the mare’s in kg). By the sixth month of lactation the same mare would gastrointestinal tract, although these should be incorporated be producing only 10.9 litres of milk per day (NRC, 2007). into her normal diet prior to the physically demanding labour. Turning the mare and the new-born foal out to pasture as soon as possible helps to keep the mare moving Table 1. Average milk production (litres/day) for a 500kg mare during months 1, 3 and 6 of lactation, and the average growth rate and grazing, and may also reduce the risk of colic. of a foal at months 1, 3, and 6 of age Month 1 Month 3 Month 6 CONSIDERATIONS DURING LACTATION Pasture is the most desirable source of forage for the Mare’s average milk production 16.3 15.0 10.9 lactating mare as it provides a better source of energy, (litres/day) protein, vitamins and minerals compared to preserved Foal’s average forages such as hay (Lawrence, 2013). Despite being such daily gain (kg/ 1.1 1.0 0.8 a good food source, pasture may not necessarily provide all day) nutrients the mare requires as its nutrient content depends on various factors such as the grass species, soil type, climate, and time of year that the mare is grazing. Analysing soil The nutritional needs of the mare vary in response to her and grass can be helpful but can prove expensive and might maintenance requirements and stage of lactation, with early not always be accurate. Providing a feed or supplement lactation classed as up to 12 weeks and late lactation being specifically designed for breeding mares is advised to ensure from 12 weeks onwards (Lawrence, 2013). Maintenance all nutrient demands are met. Mares that are to be stabled requirements are the amount of nutrients the mare requires more frequently will also require additional vitamins and to maintain her own body and normal functions, which minerals through a concentrate feed or supplement. The increase by approximately 10% in lactating mares. Mares better the quality of forage the mare receives, the lower managed outside will have higher maintenance requirements the amount of concentrate feed she will need to be fed, as they generally spend more time moving and also have however not all vitamin and mineral requirements may be to regulate their own temperature in different weather met if feeding less than the recommended daily amount of conditions. In addition to maintenance requirements, the feed, meaning supplementation is likely to be needed. If mare also requires specific nutrients for milk production, mares are kept as a group at pasture, it may be difficult to with the higher milk production in early lactation requiring feed individually and ensure they are receiving the desired higher nutrient intakes compared to requirements during nutrients, so feeding in individual stables or pens can late lactation when milk production is less (NRC, 2007). ensure the correct amounts are received. 26 27Table 2. Daily nutrient requirements of a 500kg broodmare in the first and sixth month of lactation Month 1 of Month 6 of % change from NRC requirements lactation lactation month 1 to month 6 Digestible Energy (Mj) 133 114 -14% Crude Protein (g) 1535 1265 -18% Amino Acids Lysine (g) 85 67 -21% Macro Minerals Calcium (g) 59 37 -37% Phosphorus (g) 38 23 -39% Sodium (g) 13 12 -8% Chloride (g) 46 46 0% Potassium (g) 48 34 -29% Magnesium (g) 17 8.7 -49% Sulphur (g) 15 15 0% Trace Elements RE Cobalt (mg) 0.5 0.5 0% PA Copper (mg) 125 125 0% P D Iodine (mg) 3.5 3.5 0% ELC Iron (mg) 500 500 0% YC Manganese (mg) 400 400 0% ER Zinc (mg) 400 400 0% %00 Selenium (mg) 1 1 0% 1 N Vitamins O Vitamin A (IU) 30000 30000 0% DET Vitamin D (IU) 3300 3300 0% NIR Vitamin E (IU) 1000 1000 0% P B1 - Thiamine (mg) 37.5 37.5 0% B2 - Riboflavin (mg) 25 25 0% Calculations based on NRC (2007) recommendations Table 2 shows the nutrient requirements of a 500kg mare in foal. Table 2 shows how the energy demand at six months lactation is reduced, although it still remains considerably her first and sixth month of lactation, respectively. higher than the energy requirement of even mares at the end ENERGY of their pregnancy. The mare is able to convert about 60% The energy requirements of the lactating mare are of her digestible energy into milk energy (Lawrence, 2013) almost double that of a mare at maintenance or in the early and providing a diet of good quality forage can reduce the stages of pregnancy. As energy demand is associated with need for concentrates to be fed to meet energy requirements the amount of work the body has to do to produce milk, (Doreau et al., 1988). Sufficient good quality grazing and the highest energy demands for the mare are during early hay are likely to be able to meet the broodmare’s energy lactation (Lewis, 1995; NRC, 2007) due to her having to needs, however all horses will greatly vary so must be produce large volumes of milk for her rapidly growing reviewed individually, with assessment of their fat stores 26 27nutritional demands of lactation, as the mare would the easiest way of determining if your mare requires more or need to consume large amounts of feed to satisfy protein less energy, as energy consumed in excess of requirements demands which would likely result in too much energy will be stored as fat. It is possible that feeding a mare on a being consumed and an increase in fat stores. The mare’s forage only diet throughout her gestation, whilst meeting requirements for protein are greatly increased due the vast her energy requirements, could reduce the risk of her foal amount of protein passing from her to the milk. Mares developing osteochondrosis by eight times compared to are able to convert approximately 35-40% of their crude those fed concentrates during gestation (Chavatte-Palmer protein intake into milk protein, depending on the protein et al., 2017). It should also be noted that providing the quality, and so a good balance of amino acids and highly mare with excess energy will not increase the growth rate digestible protein should be provided (Lawrence, 2013). of the foal and may even produce higher quantities of less Insufficient protein in the diet over a prolonged time will concentrated milk (Pagan & Hintz, 1986). decrease milk production and cause the mare to lose muscle and topline, whilst a diet containing protein comprising non-essential amino acids (known as low quality protein) results in a reduced milk yield (Lawrence, 2013). We can see from Table 2 that in the early stages of lactation, a 500kg mare requires 85g of the essential amino acid Lysine and so over 5% of her crude protein intake must contain Lysine. Due to the requirement for essential amino acids in the body, it is more important to meet the amino acid requirements of the mare than the overall crude protein needs. Achieving this may mean that the amount of protein in the diet is increased to meet the amino acid demand (Lawrence, 2013). VITAMINS AND MINERALS Figure 2. A balanced diet is essential for the mare to ensure her milk can Whilst some vitamins and minerals may have a greater provide the nutrients the foal needs for correct growth and development influence than others, it is not only the quantities that they are supplied in the diet that must be considered. Some If the mare’s diet is severely deficient in energy, especially nutrients should be fed in the diet in specific ratios to aid if she has a low body condition score prior to foaling, then correct utilisation and avoid them competing for absorption she will likely lose weight and this can reduce foal birth or influencing the uptake of other nutrients, especially when weight and growth (Doreau et al., 1988; Chavatte-Palmer et al., 2017). If only in moderate energy deficit (80% of some are provided in excess (NRC, 2007). energy requirements met) it is unlikely to have any effect CALCIUM AND PHOSPHORUS of foetus growth or the foal’s growth after birth due the The Calcium to Phosphorus ratio in the horse’s skeleton placental adaptation (Chavatte-Palmer et al., 2017). is 2:1, and 1.7:1 within the whole body (Frape, 2010). PROTEIN AND PROTEIN QUALITY Calcium is the mineral that creates a strong skeletal Protein requirements for a mare in early lactation are system and therefore the lactating mare has an increased triple those of the mare when she is not pregnant (NRC, demand to ensure that her suckling foal receives sufficient 2007). This considerable increase in protein requirements quantities for its skeleton to growth and develop. Calcium shows how simply feeding more feed is unlikely to meet requirements for lactating mares are 1.8 to 2.8 times higher 28 29than a horse at maintenance, with the highest levels during Vitamin E is a well-known antioxidant crucial to support the horse’s immune system and can often be seen paired in the early stages of lactation (months 1 to 3) (NRC, 2007). supplements with Selenium. Whilst toxicity of Vitamin E Providing insufficient Calcium increases the chances is unlikely, inadequate intake of Vitamin E and Selenium of bone demineralisation, yet over-supplementing does during the mare’s pregnancy and lactation period has a not provide any additional benefit to the foal’s skeletal direct effect, causing deficiency in her foal from birth to development (Lawrence, 2013). The NRC (2007) also one month of age (Lawrence, 2013). A study by Bondo shows that Phosphorus requirements increase by similar and Jensen (2011) found that supplementing mares with amounts (1.7 to 2.7 times maintenance requirements), with Vitamin E during the late gestation period resulted in the highest levels during early lactation. higher levels of immunoglobulins in their milk and their foals were found to have improved immunoglobulin levels OTHER NUTRIENTS and Vitamin E status. Iodine is highly digestible (Frape, 2010) and is vital for the synthesis of thyroid hormones such as thyroxine and The mare will also have an increased need for water with triiodothyronine, which are needed to regulate the horse’s studies showing that broodmares require 1.8 to 2.5 times basal metabolic rate (energy expenditure at rest) (NRC, more water than is needed for a horse at maintenance. Keep 2007). Selenium also aids thyroid hormone metabolism R clean fresh water available at all times, ensuring troughs do EP as well as acting as an antioxidant (NRC,2007). The trace A not freeze if outside. Monitoring the mare's water intake P nutrients Iodine and Selenium play an important role and D just prior and during labour can indicate potential problems. EL should be balanced in the diet as these trace elements can CYC affect the mare’s fertility and viability of her foal, whether MONITORING BODY CONDITION AND FAT STORES ER Monitoring the fat stores of the mare is a simple yet the mares diet is providing excess or deficient amounts %00 effective way of adjusting the amount of energy being (Frape, 2010). 1 NO DE Abigail Malone, BSc, Senior TNI Nutritionist at Feedmark RP Abigail has worked as the Senior Nutritionist at Feedmark for almost two years. Abigail studied International Agriculture and Equine Business Management at the Royal Agricultural University in Cirencester where she took her final year electives in Equine Nutrition and Equine Health. After leaving university Abigail went on to work in a variety of equine industries in Europe and Australia, including stud farms, racetracks, and eventing yards where she worked bringing on young horses. Over the years Abigail has brought on her own young horses to event, leading to her keen interest in performance horse nutrition. By combining her practical and technical knowledge, Abigail provides accurate and practical advice to horse owners. 28 29consumed as it allows the breeder to visually monitor the in optimal condition before foaling. A mare with excessive mare with little stress or change in routine. Maintaining weight and a mare that is underweight can both cause issues optimum fat stores is key throughout the pregnancy and during foaling and there can be ongoing implications for crucial during lactation as some mares prone to weight the mare’s health. gain, such as heavy breeds or ponies, will require close SUMMARY monitoring and an appropriate feeding regime to reduce Caring for the broodmare can seem daunting as there are excess fat accumulating. Excess body weight also increases many factors to consider, however it should be remembered strain on the musculoskeletal system which can impair her that the mare can be fed and managed as normal until the 5th mobility and comfort. month of pregnancy, when the requirements of energy and If energy requirements are not met, the mare will use some nutrients increase. After this time it is recommended her own body fat stores to continue lactating, resulting in to review her diet and management to optimise foetal weight and condition loss (Lawrence, 2013). A suckling development and mare health, and to keep these under foal can rapidly lower the fat stores of an already thin mare. review throughout the remaining pregnancy and during Once a lactating mare has lost condition it can be difficult to lactation, making any changes gradually. For many mares regain as an increased amount of feeding, especially large a forage-based diet supplemented with vitamins, minerals volumes of concentrates, could lead to other risks such as and quality protein will meet all of their requirements colic. This emphasises the importance of the mare being whilst avoiding the likelihood of excess weight gain. REFERENCES Bondo, T., & Jensen, S.K. (2011). Administration of RRR‐α‐tocopherol to pregnant mares stimulates maternal IgG and IgM production in colostrum and enhances vitamin E and IgM status in foals. Journal of Animal Physiology and Animal Nutrition, 95(2): 214-222. doi.org/10.1111/j.1439- 0396.2010.01043.x Chavatte-Palmer, P., Peugnet, P., & Robles, M. (2017). Developmental programming in equine species: relevance for the horse industry. Animal Frontiers, 7(3): 48-54. doi.org/10.2527/af.2017-0128 Chenier, T.S., & Whitehead, A.E. (2009). Foaling rates and risk factors for abortion in pregnant mares presented for medical or surgical treatment of colic: 153 cases (1993-2005). The Canadian Veterinary Journal, 50(5): 481-485. Cilek, S. (2009). The survey of reproductive success in Arabian horse breeding from 1976-2007 at Anadolu State farm in Turkey. Journal of Animal and Veterinary Advances, 8(2): 389-396. Dicken, M., Gee, E.K., Rogers, C.W., & Mayhew, I.G. (2012). Gestation length and occurrence of daytime foaling of Standardbred mares on two stud farms in New Zealand. New Zealand Veterinary Journal, 60 (1): 42-46. doi:10.1080/00480169.2011.632340 Doreau, M., Martin-Rosset, W., & Boulot, S. (1988). Energy requirements and feeding of mares during lactation: A review. Livestock Production Science, 20(1): 53-68. doi.org/10.1016/0301-6226(88)90053-X Frape, D. (2010). Equine Nutrition and Feeding, 4th Ed. Wiley- Blackwell, UK. Kubiak, J.R., Evans, J.W., Potter, G.D., Harms, P.G., & Jenkins, W.L. (1989). Parturition in the multiparous mare fed to obesity. Theriogenology, 32(1): 27-36. doi:10.1016/0093-691x(89)90518-9 Lawrence, L.M. (2013). Feeding Stallions and Broodmares. In: Geor, R.J., Harris, P.A., & Coenen, M. (eds) Equine Applied and Clinical Nutrition. Elsevier Ltd, UK. Lewis, L.D. (1995). Equine Clinical Nutrition: Feeding and Care. Williams & Wilkins, USA. NRC (2007). Nutrient Requirements of Horses, 6th Ed. The National Academies Press, Washington, USA. Pagan, J.D., & Hintz, H.F. (1986). Composition of milk from pony mares fed various levels of digestible energy. The Cornell Veterinarian, 76(2): 139-148. Satué, K., Felipe, M., Mota, J., & Munoz, A. (2011). Factors influencing gestational length in mares: A review. Livestock Science, 136: 287-294. doi. org/10.1016/j.livsci.2010.09.011 Steel, C.M., & Gibson, K.T. (2002). Colic in the pregnant and periparturient mare. Equine Veterinary Education, 14(5): 5-15. doi. org/10.1111/j.2042-3292.2002.tb01788.x Thomas, H.S. (2020). How to Predict Foaling. Published on the Internet; https://thehorse.com/148247/how-to-predict-foaling/. [Accessed 1 April 2021] Wilsher, S., & Allen, W.R. (2003). The effects of maternal age and parity on placental and fetal development in the mare. Equine Veterinary Journal, 35(5): 476-483. doi:10.2746/042516403775600550 30 31Nutrition for hoof health Abigail Malone, BSc Multiple factors influence the health and quality of our to growing strong healthy hooves is feeding a balanced diet horse’s hooves, and as the old phrase goes “no hoof, no that provides all the components required by the body to horse”. A survey conducted by Thirkell & Hyland (2017) make the hoof structures. However, for horses and ponies shows that hoof issues are extremely common, with 89% that struggle with weak hoof horn or that have slow hoof of UK horses experiencing hoof problems in the last 5 growth, providing certain nutrients at higher levels can help years, therefore it is important to focus on hoof health. The the body to produce strong hoof structures. The beneficial external environment of the hoof influences its structures, effect of feeding such nutrients on hoof quality may not be with excessively dry conditions being associated with seen for several months, not because they have no effect, brittle hooves that are prone to chipping and cracking, but because mature horses’ hooves grow relatively slowly whilst excessively wet conditions are associated with soft at a rate of 8-12mm per month, meaning it can take 9 soles. A wet environment does not appear to influence the to 12 months for changes in hoof quality to be seen moisture level of the hoof wall but is thought to increase the (Frape, 2010). R incidence of white line disease due to the effects on the sole E INFLUENCE OF NUTRIENTS ON HOOF HEALTH P (Hampson et al., 2012; O’Grady & Burns, 2021). Providing A A balanced diet means your horse consumes all the P access to a dry area where your horse can spend some of its D nutrients its body requires to maintain health and perform EL time is helpful in supporting hoof health, alongside regular C any physiological functions required, such as repair of YC cleaning and routine trimming by a qualified professional. E tissues, growth, exercise, or reproduction. A balanced diet R ensures all required nutrients are consumed in appropriate %00 quantities to meet demand but not impair the absorption 1 N or function of other nutrients, which can lead to nutrient O D deficiencies (NRC, 2007). Nutrients are classified into ET six main categories: water, fats, carbohydrates, protein, NIRP vitamins, and minerals. To survive the horse needs to consume specific nutrients from each of these categories, plus energy, although energy is not classed as a nutrient as it is gained from the processing of carbohydrates, fats and proteins (McDonald et al., 2011). Vitamins are organic Figure 1. Achieving good hoof health is a combination of appropriate substances which can be found in the horse’s forage and nutrition, suitable management, and regular care concentrates, and minerals are inorganic elements that Hoof quality and growth is influenced internally by the come from water and soil that are then absorbed by plants horse’s genetics and the nutrients it consumes. Genetics are and consumed by the horse. Minerals can be categorised difficult to influence, although some issues such as hoof into macro minerals and micro minerals (also known as wall separation disease (HWSD) that affects Connemara trace elements), based on the amount they are required in ponies, can be reduced by testing for the genetic mutation the diet (McDonald et al., 2011). and not breeding affected animals (Logie, 2017). We know It is the balance and the combination of these nutrients that some horses seem to naturally have strong healthy that will improve hoof health and growth, as some nutrients hooves whilst others struggle with poor hoof quality, with in excess can be detrimental to hoof development. Table some breeds seeming predisposed to inferior hoof horn 1 shows the nutrient requirements for a 500kg horse at quality (Josseck et al., 1995). Aside from genetics, the key 30 31maintenance consuming 10kg of food per day (as dry by way of lack of correct nutrients for hoof health. If horses matter), equivalent to 2% of its body weight. The stated are in negative energy balance, either purposefully due requirements are the minimum values for a balanced diet to being on a diet, or due to an inappropriate food intake, to keep the average horse healthy, with nutrients that play a they will first utilise their body fat stores with the potential key role in the health and growth of the hoof shown in bold. of then using their protein stores to provide energy, thus We will take a look at these nutrients in more detail. reducing the availability of protein to support hoof health, which can have detrimental effects on hoof health as we Table 1. Nutrient requirements for a 500kg horse at maintenance fed at 2% body weight will later discuss. A study by Butler & Hintz (1977) showed Nutrient Daily requirement a 50% greater growth in the hoof wall with ponies fed a Digestible energy (Mj) 69.7 positive energy balance compared to those on restricted Crude protein (g) 630 diets. Such findings indicating that equids on a restricted Amino acids diet may benefit from feeding additional nutrients. Lysine (g) 27 A study using 48 horses by Ley et al. (1998) over a Macro minerals 12-month period showed that seasonal movements and Calcium (g) 20 nutritional regimes significantly affected the strength of Phosphorus (g) 14 the horses’ hoof wall as well as its mineral composition. Sodium (g) 10 Horses fed a more balanced diet, according to the NRC Chlorine (g) 40 recommendations at the time, had greater hoof tensile Potassium (g) 25 strength, showing that a forage-only diet is unlikely to Magnesium (g) 7.5 provide the horse with sufficient nutrients for a balanced Sulphur (g) 15 diet, and that horse owners should consider ways to feed Cobalt (g) 0.5 nutrients that will optimise hoof growth rate and quality Trace elements horn production. Copper (mg) 100 Iodine (mg) 3.5 In a study by Jancikova et al. (2012) horses supplemented Iron (mg) 400 with vitamins, minerals and amino acids had 22.3% higher Manganese (mg) 400 hoof horn growth with sufficient quality, than a control Zinc (mg) 400 group of horses not being fed the supplement. These Selenium (mg) 1 findings support an earlier study Butler & Hintz (1977) Vitamins which reported a 50% increase in hoof horn growth rate Vitamin A (IU) 30,000 when ponies were fed an ad libitum pelleted feed compared Vitamin D (IU) 3,300 to those with a restricted ration. Although this type of Vitamin E (IU) 500 feeding may not be appropriate for all horses and ponies, it B1 (Thiamine) (mg) 30 does lead us to believe that those on a restricted diet would B2 (Riboflavin) (mg) 20 benefit from supplementation of certain nutrients. Calculations based on NRC (2007) recommendations PROTEIN AND AMINO ACIDS ENERGY AND FOOD INTAKE The hoof comprises mainly of keratin, a protein made of All horses are recommended to be fed 2% of their body amino acids which contributes to the durable structure of weight daily on a dry matter (DM) basis, with at least 1.5% the hoof wall (Frandson & Spurgeon, 1992). As the horse of their body weight being fed as forage, although higher is not able to produce all the amino acids it requires, some forage intakes are ideal for general and digestive health. amino acids must be supplied in the diet, these are referred Feeding less forage than this is likely to cause problems to as essential amino acids. Amino acids are the building such as gastric ulcers and colic, and could be detrimental blocks of protein, with Lysine being the first limiting amino 32 33acid, meaning it is the amino acid that is likely to first their own PUFAs, they must be provided within their diet, become deficient in the horse’s diet (McDonald et al., making them essential nutrients. Fatty acids have numerous 2011). When Lysine is deficient, the synthesis of proteins benefits to the horse with omega-3 fatty acids having an within the body is limited, even if all other amino acids anti-inflammatory response, whilst omega-6 fatty acids are are present in adequate amounts. As such, it is essential proinflammatory, making it more ideal to choose a feed or to provide adequate Lysine in the diet, with some good oil with a higher omega-3 to omega-6 ratio. Marine derived sources being Soya bean meal, Spirulina and Fenugreek omega-3 sources, commonly from fish and algae, contain seeds. Providing Lysine alongside amino acids Threonine eicosapentaenoic acid (EPA) and docosahexaenoic acid and Methionine within the diet will aid keratin synthesis (DHA), whilst those obtained from plants, such as linseed, and optimise hoof quality. contain alpha-linolenic acids (ALA). Alpha-linolenic acids are the longest of the PUFAs and can be broken down by Methionine is frequently recommended and can be the horse to EPAs and DHAs, however the horse is not found in many feeds (alfalfa, sugar beet pulp, rice bran) particularly efficient at undertaking this process, making it and supplements. Methionine is important because the more beneficial to provide a marine based omega-3 source horse converts it to Cystine, an amino acid which provides (Warren, 2015). Traditionally cod liver oil was used to keratin with its structure and durability, however Vitamin provide such nutrients however producing fish oil is highly B6 (Pyridoxine) must also be present in the diet to allow R unsustainable and brings about a controversial matter, with E this to happen (Kellon, 1998). Methionine and Cystine PA horses being naturally vegan some owners may be hesitant P are Sulphur-containing amino acids, a macro mineral also D to feed a fish-based product, whereas algae is an excellent E required for keratin growth (Jancikova et al., 2012). Care L vegan alternative. C must be taken not to over supplement the horse’s diet YCE with Methionine as it is possible that this may reduce the VITAMINS R % Biotin (also known as Vitamin B7 and Vitamin H) is absorption of Copper, Zinc and Iron (Anon, 1998), leading 001 the most widely researched vitamin with regards to hoof to white line disease and degeneration of the hoof wall. N health, yet it also supports growth of the coat, mane and O A diet that is protein deficient can lead to a slower rate D tail due to its role in the formation of keratin. Whilst B E of hoof growth as well as cracking and splitting (Lewis, TN vitamins, including Biotin, are by-products produced from I 1995; NRC, 2007). It is unlikely that a UK forage only diet, RP fibre fermentation within the horse’s hindgut, it may be especially if limited or no grazing is offered, will provide beneficial to provide additional Biotin in the diet. In one sufficient levels of Lysine and Methionine, which is where a of the first studies regarding Biotin, Buffa et al. (1992) broad-spectrum vitamin and mineral supplement/balancer, using 24 horses, found that supplementing 15mg of Biotin or a specifically designed hoof supplement containing compared to 7.5mg showed better hoof growth rates and amino acids can help to meet the horse’s requirements. Such hardness. Further studies showed that supplementing 1mg products are often low in calories making them suitable for of Biotin per day to a 500kg horse is adequate to support those prone to gaining weight. general health (Geyer, 2005), however a study by Josseck FATTY ACIDS et al. (1995) showed that feeding 20mg per day to a 500kg Omega fatty acids are long chains of carbon and hydrogen horse had a more positive effect on hoof health and growth. atoms that form polyunsaturated fatty acids (PUFAs) that Reilly et al. (1998) found a 15% increase in hoof horn give structure to the cell walls in the body’s tissues and growth rate after 5 months, after supplementing ponies aid the absorption of the fat-soluble vitamins A, D, E and at a higher rate of 0.12mg/kg body weight, equivalent to K (NRC, 2007). Fatty acids are components of the cement 60mg for a 500kg horse. It is advised that horses who are that binds the individual cells of the hoof and also form a prone to weak, brittle or cracked hooves, receive long term permeable barrier that controls hoof moisture level, making supplementation of Biotin to maintain the growth rate of them important for hoof quality. As horses cannot produce the horn (Geyer and Schulze, 1994) as when supplementary 32 33(Kellon, 2019). Some farriers have now even started to use dietary Biotin is reduced or removed, the hoof may once Copper nails when shoeing horses due to Coppers potential again deteriorate. When looking for an additional feed or antibacterial effect, although this depends on the type of supplement for hoof health it is advisable to select one with shoe used. A study by Jancikova et al. (2012) using 16 20mg per day or above for a 500kg horse. Warmblood horses showed that providing supplemental It is important to meet the requirements of all vitamins, Copper and Zinc increased the content of these trace not just Biotin, to maintain the general health of the elements found within the dry matter of the hoof horn. horse, and is one reason it is necessary to provide feeds A study by Higami (1999) found that horses were more and supplements that provide balanced nutrients. Many likely to experience white line disease when consuming a vitamins are sensitive to ultraviolet light, therefore forage low Copper and Zinc diet compared to those supplemented will lose a large proportion of its vitamin content during with raised levels of these trace minerals. UK soils are often the harvesting process and these levels will continue to low in Copper and Zinc which generally means that the deplete over time in storage. Many nutrients within hay are forage grown in these soils are also low in these nutrients. also lost through the soaking process, so if this is a practice Horses grazing such areas or consuming forage harvested you use for your horse’s forage, evidence suggests that a from such land may be more susceptible to associated vitamin and mineral supplement will support deficiencies deficiencies, meaning an additional supply of such nutrients and provide known amounts. are required through the feed or supplementation. Calcium and Phosphorus Calcium is a macro mineral and is required in all horses’ diets to support the development of many structures within their body, such as bones, teeth and muscles, as well as for normal hoof growth. Within the actual hoof structure, Calcium is only present in very small quantities, yet it is Figure 2. A diet deficient in some amino acids, vitamins and minerals can lead to slow hoof growth rate and hoof horn that is prone to cracking vital to help make cross-links of Sulphur between proteins in the hoof horn (Geyer, 2005), in turn creating a stronger MINERALS and healthier hoof. A study by Ley et al. (1998) showed Zinc and Copper that seasonal changes affected the Calcium content of Zinc is a trace mineral that is responsible for numerous hooves in 48 Thoroughbred horses, with horses showing roles within the equine body such as growth rates and cell a significantly higher Calcium content within their hooves division (Kellon, 1998). Zinc is involved in the uptake of during spring, summer and autumn compared to the amino acids and Sulphur, and thus the synthesis of keratin. winter, likely due to higher Calcium content within For Zinc to be absorbed it must be provided in the correct forage and grass. ratio to Copper, another trace mineral, at 4 parts Zinc to 1 We can see from table 1 that Calcium is a large part Copper (4:1). Zinc can be found in high concentrations proportion of the minerals required for a balanced diet within the hoof tissue and so a deficiency can be easy to which can vary significantly depending on the individual detect. Slow hoof growth, thin walls and weak horn can horse’s needs. Taking these variations into account will all indicate a Zinc deficiency (Kellon, 2019). Copper aids ensure that there is no deficiency. Young horses, breeding the formation of bone and connective tissues including the horses and those in hard work will require increased levels cross-links within keratin that give the hoof its strength and of Calcium and a deficiency may cause a loss of tubular density, with deficiencies causing abnormalities in the bone, structure within the inner walls of the hoof structure (Frape, connective tissues and potentially reducing hoof growth 2010). It must not be forgotten that Calcium should be (Kellon, 1998). Increased cases of laminitis, thrush and abscesses could also indicate Zinc and Copper deficiencies balanced with Phosphorus in the ratio at 2 parts Calcium to 34 35METHYL SULPHONYL METHANE 1 part Phosphorus (2:1). If the Phosphorus intake is higher than that of Calcium, then Calcium absorption may be Typically known for its joint supporting qualities, Methyl hindered leading to chronic Calcium deficiency, even if the sulphonyl methane (MSM) is also high in biologically actual level of Calcium in the diet meets requirements available Sulphur, which is important for keratin formation. (NRC, 2007). Therefore, supplementation with MSM can help improve hoof quality (Frape, 2010). Selenium Selenium has become popular within equine supplements SUMMARY as it is an antioxidant that prevents the oxidation of fats and We have explored the nutritional needs for hoof health aids correct muscle development in the horse (NRC, 2007). from general diet to more key nutrients, showing that with We are all aware that providing a balanced diet is important, regards to correcting abnormalities or weaknesses, nothing but it is just as important not to over supplement. As shown is a quick fix. The addition of nutritional supplements in table 1, the recommended maintenance daily feeding present many benefits, which are seen through continued rate for the average 500kg horse is 1mg of Selenium. Horse use over an extended period of time, and which allow the owners must be careful not to over supplement their horse’s renewal and growth of the whole hoof. It is clear that an diets with Selenium as high levels are extremely toxic all-round balanced diet is needed, with close attention paid and Selenium toxicity can have detrimental effects on the to the initial forage consumption followed by the provision hooves, leading to sloughing, cracking, and in severe cases R of additional Biotin, amino acids, omega-3 fatty acids, as E shedding of the hoof wall (Frape, 2010). Geyer (2005) PA well as various minerals. As some horses may have higher found that excess Selenium caused the decay of the hoof P D nutritional demands depending on factors such as genetics horn close to the coronet band. The levels of Selenium in ELC or their environment, it is crucial to analyse each horse or soils can vary greatly, causing a range of concentrations in YC pony's needs on an individual basis to provide them with grazing and forages, making a further case for the benefits ER opportunity for the most improvements. of testing your soil and forage for Selenium levels. %001 N REFERENCES O Anon (1998). Nutritional needs of the hoof. Journal of Equine Veterinary Science, 18(7): 456. doi.org/10.1016/S0737-0806(98)80037-3. Buffa, E.A., Van Den Berg, S.S., Verstraete, F.J.M., & Swart, N.G.N. (1992). Effect of dietary biotin supplement on equine hoof horn growth rate and DE hardness. Equine Veterinary Journal, 24(6): 472-474. doi.org/10.1111/j.2042-3306.1992.tb02879.x T Butler, K.D., & Hintz, H.F. (1977). Effect of Level of Feed Intake and Gelatin Supplementation on Growth and Quality of Hoofs of Ponies. Journal NI of Animal Science. 44(2): 257-261. doi.org/10.2527/jas1977.442257x R Frandson, R.D., & Spurgeon, T.L. (1992). Anatomy and Physiology of Farm Animals,5th Ed. Lippincott Williams & Wilkins, USA. P Frape, D. (2010). Equine Nutrition and Feeding, 4th Ed. Wiley- Blackwell, UK. Geyer, H. (2005). Nutritional Management to keep the Hoof Health. In: A.Lindner (ed.). Applied Equine Nutrition: Equine Nutrition Conference (ENUCO) 2005. Netherlands: Wageningen Academic Publishers. 43-58. Geyer, H., & Schulze, J. (1994). The long-term influence of biotin supplementation on hoof horn quality in horses. Schweizer Archiv fur Tierheilkunde, 136(4): 137-149. Hampson, B.A., Laat, M.A., Mills, P.C., & Pollitt, C.C. (2012). Effect of environmental conditions on degree of hoof wall hydration in horses. American Journal of Veterinary Research, 2: 435-438. doi:10.2460/ajvr.73.3.435 Higami, A. (1999). Occurrence of white line disease in performance horses fed low zinc and low copper diets. Journal of Equine Science. 10: 1-5. doi.org/10.1294/jes.10.1 Thirkell, J., & Hyland, R. (2017). A Preliminary Review of Equine Hoof Management and the Client–Farrier Relationship in the United Kingdom. Journal of Equine Veterinary Science, 59: 88-94. doi:10.1016/j.jevs.2017.10.005 Jancikova, P., Horky, P., & Zeman, L. (2012). The effect of feed additive containing vitamins and trace elements on the elements profile and growth of skin derivatives in horses. Annals of Animal Science, 12(3): 381-391. doi:10.2478/v10220-012-0032-4 Josseck, H., Zenker, W., & Geyer, H. (1995). Hoof horn abnormalities in Lipizzaner horses and the effect of dietary biotin on macroscopic aspects of hoof horn quality. Equine Veterinary Journal, 27(3): 82-175. doi:10.1111/j.2042-3306.1995.tb03060.x Kellon, E.M. (1998). Equine Supplements and Nutraceuticals: A Guide to Peak Health and Performance Through Nutrition. United States of America, Breakthrough Publications. Kellon, E.M. (2019). Feeding for Horse Hoof Health by Dr Kellon. Published on the Internet; https://forageplustalk.co.uk/feeding-horse-hoof-health- dr-kellon/. [Accessed 30 March 2021] Lewis, L.D. (1995). Equine Clinical Nutrition: Feeding and Care. United States of America, Williams & Wilkins. Ley, W.B., Pleasant, R.S., & Dunnington, E.A. (1998). Effects of season and diet on tensile strength and mineral content of the equine hoof wall. Equine Veterinary Journal, 26: 46-50. Logie, S. (2017). Hoof wall separation disease. Equine Health, 35: 18-20. doi:10.12968/eqhe.2017.35.18 McDonald, P., Edwards, R.A., Greenhalgh, J.D.F., Morgan, C.A., Sinclair, L.A. & Wilkinson, R.G. (2011). Animal Nutrition, 7th Ed. Pearson Education Ltd. NRC (2007). Nutrient Requirements of Horses, 6th Ed. Washington, USA, The National Academies Press O’Grady, S.E., & Burns, T.D. (2021). White line disease: A review (1998-2018). Equine Veterinary Education, 33(2): 102-112. doi.org/10.1111/ eve.13201 Reilly, J.D., Cottrell, D.F., Martin, R.J., & Cuddeford, D.J. (1998). Effect of supplementary dietary biotin on hoof growth and hoof growth rate in ponies: a controlled trial. Equine Veterinary Journal, 26: 51-57. doi.org/10.1111/j.2042-3306.1998.tb05122.x Warren, H. (2015). Algae for Horses. Equine Health, 21: 10-13. Doi.org/10.12968/eqhe.2015.1.21.10 34 35Research Roundup: Highlights from the 10th European Equine Health & Nutrition Congress The European Equine Health & Nutrition Congress is This study wanted to find out if the recommendation that forage should form the foundation of all equine diets is an international meeting of equine professionals that takes being put into practice by owners. Overall, 63% of owners place every two years. The 10th Congress has the theme were feeding the minimum recommended amount of forage ‘Fibre First’ and is taking place virtually over five separate (1.5% body weight as dry matter) which is an encouraging dates throughout 2021 and 2022. The first two days took result, however this still meant that over a third of owners place on 25th and 26th March this year, with the first day were not feeding adequate forage that we know is needed focusing on forage and the second day focusing on parasite for gastrointestinal and mental health of our equines. control. After presentations there was plenty of discussion, Owners were also asked if they viewed forage as important and with delegates from 39 countries in attendance, views for their horse’s health and all survey participants stated it and experiences varied widely. was important, indicating that there is discrepancy between The need for forage to be the foundation of all equine what people value in theory, and the choices they make diets was cemented in the first presentation delivered by when managing their horses. These results are similar to Professor Harris (WALTHAM Petcare Science Institute), previous studies undertaken in other countries and indicate with the term forage referring to whole plants (except roots) that more needs to be done to support owners in providing of grass or legume species, in either fresh form as grass or suitable diets. preserved as hay or haylage. This definition supports the The final presentation of day one was very useful for points emphasised in the article Fuel or filler? What is the providing such support to owners as it reviewed what we real nutrient content of grass for horses? that grass, as well know about managing our horses’ grass intake. Dr. Longland as preserved forages, are important sources of energy and (Equine and Livestock Nutrition Services) discussed the nutrients that need to be accounted for in our horses’ diets. effects of grazing time, grass height, strip grazing and the Indeed, Professor Harris demonstrated that forage only use of muzzles on grass intake. Many of the points of this diets can provide adequate energy for horses performing presentation are covered in detail in the article Managing high levels of exercise but emphasised that the variability our horse’s grass intake. The take home messages are in nutrients within forages means the horse’s other nutrient that many horses, ponies and donkeys will consume high requirements are unlikely to be met from forage alone. volumes of grass if permitted which often leads to weight Forage nutritional analysis is the key to balancing the diet gain, and for some animals can trigger health issues such and selecting a suitable feed or supplement, although it was as laminitis, therefore a suitable method of controlling that acknowledged that there is variability in analytical methods intake is likely to be required. A combination of approaches and standards used by labs meaning owners should select is most likely required as equines have shown great ability analytical services that use labs with good in-house quality to adapt to grazing practices and compensate for periods control systems. when grass intake is limited. Finding out what works best The next presentation by Professor Hesta (Ghent for your horse, pony or donkey and with your facilities may University) shared findings from a study into the feeding take some trial and error, but it is important to be able to practices of horse owners in Belgium and Netherlands. manage their grass intake. 36 37(Professor Meana Mañes, University Complutense of Day two of the congress began with Professor Madrid) to reflect differences in the climate of these two areas Claerebout (Ghent University) providing a comprehensive (temperate vs Mediterranean). Dr. van Doorn explained review of the different parasite species affecting horses, that development of small strongyle (cyathostominae) their life cycles, and monitoring techniques available. Key eggs into larvae on the pasture requires an environmental to reducing parasite infections is breaking the parasite’s temperature of approximately 10°C, and that optimum egg- life cycle, which for horses with access to pasture, means larvae development is achieved with warmer temperatures reducing the number of parasite eggs and larvae in the (20-25°C), leading to higher levels of larvae on pasture grass, so horses cannot be reinfected, and the life cycle during late spring and summer. However, the cooler cannot continue. The most effective way of achieving this temperatures of most North-Western European winters do is to monitor horses to identify those who shed eggs and not necessarily kill eggs as is sometimes believed, instead larvae, and therefore need treatment with anthelmintics the eggs remain viable during these colder periods and then (wormers), and identify those who are not shedding eggs/ as temperatures rise, they develop into larvae. It is actually larvae and therefore do not requirement treatment. By only high temperatures that reduce strongyle egg and larvae treating those that shed, the levels of anthelmintic resistance development, as explained by Professor Meana Mañes. will be reduced. This is extremely important as no new R In hotter climates eggs and larvae are more prevalent on anthelmintic treatments are being developed. Monitoring EPA pasture during the autumn and reduce over the summer is straightforward with faecal egg counts, saliva tests and P D months due to the hot, dry weather. The hot summers blood tests. Professor Claerebout explained that the amount ELC however result in high numbers of bot flies, which were of testing performed should reflect the potential risks, so YC the most prevalent parasite reported in the study during this for premises where field groups are relatively stable, testing ER season. These differences highlight how climate should be 3-4 times in the grazing season is likely to be suitable, and %001 considered when developing parasite control plans. composite samples, where faecal samples from multiple N horses (maximum 10 samples) are put together and O The final sessions of the congress discussed D a subsample taken and tested, are an option. E nutritional options for controlling parasite TN For more I On premises where field groups change R infections. This is a relatively new and P information about frequently, more frequent testing of exciting area of equine research that has the 10th European Equine individual animals is recommended. potential to help support other parasite Health & Nutrition congress Testing younger horses more regularly monitoring and treatment practices. and how you can register for the is also recommended as they are more Dr. Paz-Silva (University of Santiago remaining dates go to www. susceptible to parasite infections. de Compostela) explained the concept equine-congress.com/ In some countries testing for parasite tenth-eehnc of biological control which is defined infections is not widely practiced, however as the use of living organisms to control the high level of uptake in the UK, Denmark pests, and how certain fungi have the potential and Netherlands was highlighted as a success. In the to reduce some parasite infections in equids through their UK the high level of testing may be due to the availability effect on eggs and larvae. Spraying the fungi onto pasture of advice and testing services from vets and Suitably or faecal piles is one method of administration, or another Qualified Persons (SQP’s, a UK specific qualification). option is to coat feed or treats with fungi, so they are administered direct to the horse where they pass through The following two presentations gave overviews of the gastrointestinal tract undigested and then act within parasite issues and control in North-Western Europe (Dr. the faeces to disrupt the parasite life cycle. This is a new D. van Doorn, Utrecht University) and Southern Europe 36 37concept being applied to equine parasite control however parasite larvae within the gastrointestinal tract, preventing results for small strongyles egg shedding by horses, the parasite life cycle from continuing. Legume plants ponies and zebra show reduced faecal egg counts so there such as Sainfoin are potential sources of such tannins, or is potential to integrate such methods with other parasite feeding a supplement or feed containing tannin extracts is control practices. Dr. Pellikaan (Wageningen University) another potential option. Although these new methods of explained another possible approach to reducing parasite controlling parasite infections are still in the experimental infections in horses, which has been taken from research stages, it is excellent to see research into this important in ruminants. Tannins are complex compounds found area. As the research continues and more knowledge and in some plant species. Tannins were previously thought evidence is gained it is hoped such practices will integrate to have harmful effects when consumed by animals, but with the monitoring and management practices already research has now shown that some tannins have anti- utilised, with the overall aim of reducing parasite resistance inflammatory, antioxidant, and antimicrobial properties. Dr to anthelmintics, and consequently parasite infections in Pellikaan explained that some tannins are able to bind to our horses. The Journal for Equine Nutrition is FREE. To get every edition of The JEN to your inbox for free, SIGN UP HERE You will receive no marketing literature, and you will be the first to receive The JEN! 38 39Glossary Organic molecules that combine to form proteins, also known as the building Amino acids blocks of proteins. Drugs that expel parasitic worms from the body by either stunning or killing Anthelmintics them, and without causing damage to the host animal. The mare’s udder swells due to the production of milk in anticipation of the foals Bagging up birth. The rate at which the body uses energy while at rest to maintain vital functions Basal metabolic rate such as breathing and keeping warm. Crude protein Calculated by the nitrogen content of foodstuffs. Loss of minerals such as Calcium, from tissues, e.g. Calcium leaves the bones Demineralisation and enters the circulation to maintain blood levels of Calcium if fed a Calcium deficient diet. Digestibility Amount of nutrient absorbed by the animal and available for it to use. REP Digestible energy Amount of energy in the feed minus the amount of energy lost in the faeces. AP The part of a foodstuff that remains after all water has been removed. Foods are DE Dry matter L compared on a dry matter basis as nutrients are only contained in the dry matter. CY Biological processes that occur outside of the body, but within laboratory C In vitro ER equipment such as a test tube or culture dish. %0 Biological processes that occur inside a whole living organism, e.g. an animal or 0 In vivo 1 person. NO Molecules that are attracted to fats. Such substances are able to dissolve much Lipophilic D easier in lipids (fats) than they are in water. ETN Minerals required in the diet at levels of more than 100mg/kg diet. Includes I Macro minerals RP Calcium, Phosphorus, Magnesium, Sulphur, Sodium, Chloride and Potassium. Microbiome Microorganisms (and their genes) living in a specific environment. Specific microorganisms (bacteria, protozoa, fungi) living in a specific Microbiota environment, e.g. the equine gastrointestinal tract. A microscopic organism, especially bacteria, protozoa and fungi. These live in the Microorganism equine gastrointestinal tract, with higher populations in the large intestine making up the microbiome. A recurring period where the female is sexual receptivity, commonly known as Oestrus being in heat or season. Surface or material on or from which an organism lives, grows, or obtains its Substrate nourishment, e.g. undigested food that reaches the equine large intestine and is used by the microorganisms to survive. Minerals required in very small amounts. Required in the diet at a level of less Trace elements than 100mg/kg diet. Includes Iodine, Manganese, Zinc, Copper, Selenium and Iron. Organic compounds which are required in small amounts for normal growth and Vitamins maintenance of life. 38 39Feedmark produce a wide range of comprehensively researched and tested supplements for horses, including... ® Best-Flex HA Probably the world’s best joint supplement. 41 YEARS AT THE CENTRE OF EVIDENCE-BASED NUTRITION™ 0800 585525 | feedmark.com 40 PB