Choosing the right feeds for your horse Sources of Energy Grains Fats Sources of protein Roughage There are many ways to feed horses, whether it be by using commercial feed mixes, or using basic grains to mix your own. There is not necessarily any correct way to feed, often it comes down to what is logistically feasible for your circumstance. It may be more cost effective to mix your own grains, however if you only have a small number of horses, having several ingredients and several feed bins may prove an arduous task. No matter how you feed, it is not only vitally important to ensure you have an adequate level of energy, protein, vitamins and minerals but that they are also provided in appropriate balance to one another. For performance, growth and maintenance, all horses need not only an adequate amount of energy, protein, vitamins and minerals, but they all must be provided for in an appropriate balance to each other. Sources of energy The main sources of energy in equine rations include cereal grains (e.g. oats, corn, barley) and oils. These may be fed as raw ingredients, or alternatively may make up part of a commercially mixed feed. Table 1. Advantages and disadvantages of oats, corn and barley Grain Advantages Disadvantages Oats Renowned as a “safe” grain. Has a high crude fibre content which dilutes the starch content reducing risk of digestive upset and laminitis if excess is fed relative to needs. Contains the lowest amount of starch but highest proportion of starch digested in small intestine. While crimping, rolling and grinding oats do not improve digestibility, they may improve palatability particularly for growing foals and older horses. Of the grains, oats has the lowest digestible energy content which increases the amount that has to be fed. There is also the suggestion that it may lead to “tying-up” in some horses. May lead to nervy, hyperactive behaviour in some horses. Corn Energy dense grain. Contains twice as much energy as oats on a volume basis and about 18% more digestible energy on a weight basis. Not well digested in small intestine. Overloading of starch into hindgut increases risk of D-lactic acid build-up, which can trigger the onset of laminitis and founder, as well as low grade diarrhoea and excitable behaviour. Aim to feed no more than 250g/100kg body weight. Barley Energy levels mid way between oats and corn. Known as a “conditioning” feed possibly due to high levels of chromium. Widely used in standardbreds and eventers. Whole raw barley is harder and less palatable than oats. Low starch digestibility (Boiling at a simmer for 10-15mins improves digestion of starch in small intestine as compared to rolling or steam flaking, now available in roasted and extruded form). Each grain has a slightly different energy value, digestibility and glycaemic index influences how your horses uses the grain. Fig 1. Comparison of energy levels of grains Fat as energy Body fat stores can be drawn upon during prolonged exercise, particularly useful for horses involved in endurance type activities. These are broken down to free fatty acids which are then aerobically metabolised to energy in working muscles.Fats cannot be converted to glucose and used during fast anaerobic exercise in athletic horses. There are several benefits to feeding fat in the diet. These include: Concentrated energy source Improves body condition and coat Increases energy without increasing bulk Decreases heat produced from digestion of grains Lower lactic acid accumulation in muscles and blood by sparing glycogen use Reduced severity of tying-up Reduced muscle damage Calmer behaviour in horses on typically high grain diets Omega-3 and Omega-6 Each oil or fat has a blend of different fatty acids (Omega-3, Omega-6) in its triglyceride content and a correct ratio of these is essential. Oils that contain higher amounts of Omega-3 are considered to provide natural anti-inflammatory compounds and hormone action to improve the function and strength of blood vessels and body cells In animals, an Omega-3 to Omega-6 fatty acid ratio of 1 part Omega-3 to 5-10 parts Omega-6 is considered beneficial. Table 2. Comparison of oils commonly used in horse feeds Oil % of Fatty Acids in Oil Comments Omega 3 Omega 6 Canola oil 10 20 Palatable, well accepted, cold pressed is stable, less risk of oxidation. Soyabean oil 8 54 Reasonably well accepted, some Omega-3, but high content of Omega-6. Corn oil 2 52 Low Omega-3, not as palatable, more easily oxidized. Sunflower oil < 1 66 Palatable. Contains high levels of Omega-6 for coat conditioning but very little Omega-3. Blended polyunsaturated cooking oil 1-5 45-60 Ratios depend on blend of oils. Canola blends contain higher Omega-3 fatty acids. Please refer to article entitled “The benefits of feeding oil as part of a horse’s ration” for further information. Sources of protein All feeds contain protein but major protein sources include Lucerne hay/chaff (17%) Oil seed Soyabean meal (45%) Cottonseed meal (41%) Linseed meal (35%) Lupin seeds (34%) Tick Beans (26%) Sunflower seeds (23%) Copra meal (22%) Yeast (50%) While the crude protein content of these meals and feeds is important, of greatest importance is the quality of protein defined by the amino acid make up of the feed. Please refer to article entitled “Protein quality and requirements in exercising and growing horses” for further information. Roughage Roughage is an extremely important part of the horse’s diet, particularly for the endurance horse. It opens up the digestive mass and traps water to aid soluble nutrient uptake, facilitates controlled fermentation to provide volatile fatty acids for energy synthesis of B Group vitamins, generates heat during fermentation to maintain body warmth and stores a reserve of fluid in the hindgut that can be absorbed as a horse dehydrates due to sweat, respiratory and urinary loss. It is recommended that horses which do not have full time access to adequate pasture should be provided with a minimum amount of roughage as hay/chaff equivalent to 1% of their body weight per day. This equates to approximately 5kg roughage for a 500kg horse. A biscuit of hay weighs roughly 2kg, so that equates to 2 biscuits of hay and 1kg of chaff (as a rough guide) per day. Table 3a. Average energy and protein levels of lucerne, oaten, meadow and wheaten hay Energy(MJ/kg) Protein(%) Lucerne 8.5 17 Oaten 7.5 9 Meadow 7.3 10 Wheaten 7 8 Table 3b. Average calcium and phosphorus levels of lucerne, oaten, meadow and wheaten hay Calcium(g/kg) Phosphorus(g/kg) Lucerne 12.2 2.2 Oaten 2.2 2.3 Meadow 6.8 2.2 Wheaten 1.3 1.8 It is not just what you feed, but also how much that makes all the difference. For further information and nutritional advice, please contact us today.