Feeds for Horses – A review

Dr Peter Huntington Kentucky Equine Research ( Australasia )

Horse owners have a bewildering array of natural feeds, processed feeds and prepared feeds available to them and it is often difficult to determine what to feed your horse. This article is a guide to what various feedstuffs contain and to help you choose the most appropriate feeds for your horse.

Concentrates

Oats
Oats are the most popular and safest grain for horses. They are very palatable, and are also the grain least likely to cause digestive upsets. Oats are lower in energy than other common grains, so over feeding is less likely to occur. They are also less dense so a dipper of oats may only have half the energy of other grains such as maize/corn. They are higher in fibre – even higher than bran, which is thought to be a high fibre feed. They are less likely to be contaminated by moulds and mycotoxins. Thus oats have a reduced risk of colic, laminitis and your horse doing too well and gaining too much weight. However they do predispose some horses to tying up and there is a widespread perception that they may induce nervousness in some horses. Oats should be the first grain included in a feeding program that requires grain.
Oats can be fed whole to horses other than foals, very old horses or those with poor teeth. The starch in oats is very digestible and crushing will only increase it a few % in horses with normal teeth.Like all grains, oats are low in calcium, but they do have a reasonably high level of phosphorus. They are a poor source of vitamins. The quality of the protein they contain is not good because they are deficient in some essential amino acids.

Maize (or Corn)
Maize is becoming more popular as a concentrate feed for horses. It has the highest energy level of all the grains. Be careful when buying cracked maize as it is susceptible to damage caused by moisture including mould. Cracked maize with a musty odour is likely to deteriorate very quickly. Do not store any cracked grain for more than 4 weeks as this increases its chance of absorbing moisture and being contaminated by mycotoxins.
Maize supplies good quantities of vitamin A. It is deficient in some amino acids and has a poor protein quality. It is very low in fibre and is thus a very concentrated feed. Do not feed large amounts of maize to horses as it can cause digestive upsets. Maize should make up no more than 25% of any grain mix. You should cut it out or reduce the amount fed on rest days. Don't swap a dipper of oats for a dipper of maize unless you want to substantially increase the energy content of the ration.
Unlike oats, the starch in maize is not digested especially well and optimum digestion requires heating e.g. extrusion, expansion or micronising.

Barley
Barley is not as palatable as oats or maize. Barley has a similar protein value to oats and is intermediate in energy between oats and maize. It is relatively low in fibre and can cause digestive upsets if not mixed with sufficient roughage. It is a hard grain and should be rolled and heated before feeding to increase palatability and energy availability. Heating can be provided by steam flaking, micronising, expanding, extruding or boiling. Boiled barley doesn’t have the magical properties some people attribute to it, but it does make up a palatable feed.

Mixed feeds
These feeds contain mixtures of grains, protein supplements, chaff, minerals, vitamins and molasses. They usually aim to provide a complete balanced feed and make the feeding up process very simple and convenient. Some feeds contain very low levels of minerals and vitamins so you still need to add a supplement, but well formulated feeds eg HYGAIN FEEDS take the guess work out of a feeding program. It is important to look closely at the feed label and select a feed that is appropriate for your horse, but unfortunately most bag labeling does not specify energy and this can be very variable. HYGAIN complete feeds do list their energy content and contain added minerals and vitamins so that when fed as directed, they do not need extra supplements.

Pellets
Firstly, pellets don’t contain the sweepings off the floor and they can be fed to racehorses. Pellets are a simple feeding method that reduces wastage and the time spent mixing feeds. They can incorporate all protein, mineral and vitamin supplements to create a balanced ration and most are designed to be fed with hay or chaff. Some pellets can crumble and be dusty particularly if handled in bulk, and you must be careful that they have sufficient fibre if fed without roughage. Have a careful look at the ingredient composition – there are many high quality pellets around but some cheaper products can hide some cheap raw materials. In particular watch out for "cool" pellets that only contain bran and pollard (Mill Run). Would you want to feed your horse a bucket full of bran and pollard?

Bran
Bran, a by-product of flour production, is mainly made up of the outer covering of the wheat grain. It does not contain as much energy as pollard or some grains, has a poor amino acid balance and is low in calcium. Bran has a very low calcium/phosphorus ratio, which can lead to weak bones if fed in large quantities without extra calcium to balance the phosphorus. It is not an essential horse feed, but is useful for mixing supplements and powders into a feed with molasses as it is so palatable. It often gives the horse a tasty meal and the owner a warm and fuzzy feeling. As with all processed feeds, bran should not have a musty odour, as this indicates the presence of moisture. Bran shouldn’t make up more than 10% of the feed and contrary to popular opinion, it is not especially high in fibre and is not a good laxative.

Pollard
Pollard is the remains of the inner kernel of wheat left after Flour milling. It is low in fibre, protein and calcium, high in phosphorus and can cause digestive upsets if it is not fed damp with chaff. Pollard is often used for fattening horses, but rice pollard and grains will do this just as effectively and with less potential problems.

Rice Pollard
Rice Pollard is high in fat and energy, and is a useful feed for putting on condition and improving coat condition. It is much more valuable than wheat pollard, but care should be taken to ensure the rice pollard isn't rancid. It can become rancid due to prolonged storage, heat and moisture. It shouldn’t be fed if it has a different smell that may indicate rancidity.

Soybean meal
Soybean meal is the best protein supplement available, however adult horses that aren’t growing may not require the quality and quantity of protein in soy meal. Raw soybeans must be processed to remove growth inhibitors including trypsin inhibitors. It is an excellent source of the essential amino acids, including lysine that are found in low levels in grain or roughage. It is not particularly palatable and a horse will eat up to 500 grams per day. Soy hulls are a source of very digestible fibre.
Full fat soy still contains 20 % oil so is higher in energy and better for the coat than normal soy meal. It is the preferred form to use in performance horses where energy is important.

Sunflower seeds
These are very palatable and are high in fat and energy so they are a good coat conditioner, but are low in several essential amino acids. Sunflowers are more a fat and energy supplement than a protein supplement. They can also be fed as a meal.

Linseed meal
Linseed meal was a very popular protein supplement for horses, yet it has the poorest quality protein of the three meals. The main reason for the popularity of linseed meal is its ability to readily produce a shine on a horse's coat, which is due to the fatty acid content of linseed oil. The other protein meals produce a similar effect to a certain degree. Linseed may also have a laxative effect because it is high in the fibre mucilage.Linseed is traditionally fed boiled in mash form and raw linseeds should not be fed as the horse can be poisoned when the seeds are fed in large amounts without being boiled.

Lupins, Beans and Peas
Other sources of protein are peas, beans, and lupins. These should be crushed, cracked or soaked to increase digestibility. They supply protein of moderate quality, but you need to feed more than the meals to achieve a required protein intake. However you don’t have any problems with ‘fines’ in the feed bin that the horse may leave. Lupins are also a good energy source for performance horses, and they are valuable as they are low in starch, but high in digestible fibre. Lupins can provide up to 25% of the total grain mix in a performance horses and can be used as a protein supplement in young horses and mares.

Roughage \ Forage
Hay and chaff are roughage. Chaff is chopped hay, so both feeds have a similar nutritional value although there is great variation in the quality and nutritional value of a particular type of roughage. Chaff has an advantage over hay in that it can be readily mixed with other feeds and this prevents a horse from "bolting" its grain. There is also less wastage with chaff, but many people overestimate the amount of chaff they feed as chaff is very light. A big bucket of chaff may contain less than a good biscuit of hay.However, it is more expensive than hay and it is cheaper and easier to feed hay to most horses. The long stem fibre in hay is also useful to maintain proper digestive function.
Hay has a lower nutritive value than the pasture from which it is made. However, a horse has to eat more of pasture than of hay to get the same amount of nutrients because pasture contains so much water. The nutritional value of hay varies greatly so it is important to check the quality of hay. High quality hay is not weathered excessively, is leafy and has minimal stems.
Good quality hay contains vitamins A, D and E, although these are destroyed after prolonged storage. Mouldy hay can cause colic and respiratory problems. Dusty hay can be soaked in water to remove the dust or not fed to horses.
Compared with the concentrates, the roughage’s are low in energy and high in fibre. This fibre is not easily digested and the main purpose is to help the normal function of the digestive tract when the horse is being fed a lot of grain. Remember that the horse evolved as a grazing animal with a high fibre diet and that the high grain/low roughage diets we feed many of our horses are unnatural and can lead to many problems. These can include digestive upsets such as colic, gastric ulcers, and diarrhoea along with metabolic disorders such as laminitis, tying up and behaviour problems.

Lucerne hay or chaff
Lucerne hay or chaff is the most nutritious roughage available. It contains the highest amounts of energy and protein and, in fact, contains more protein than any grain. This protein is of high quality. Lucerne hay or chaff is also particularly high in calcium. All the concentrates contain low amounts of calcium, so lucerne helps to balance the diet if fed with them. Lucerne may cause some horses to have sloppy droppings and will change urine characteristics, but it does not cause most of the problems that are attributed to it.

Wheaten/Oaten hay and chaff
Wheaten and oaten hay and chaff are similar in feed value. They do not contain as much protein or calcium as lucerne, but are higher in fibre and are just as palatable. The energy value of these hays or chaffs depends on the amount of grain they contain. A good sample will have a higher energy value than lucerne. Like lucerne chaff, a major advantage is that you can mix the chaff with grain to slow down the intake of concentrates.

Grass/Meadow hay
Grass hay varies considerably in quality, particularly in relation to such factors as the pasture species and the time of cutting. The more clover a pasture contains, the greater the nutritive value of the hay. And the earlier it is cut, the higher its levels of protein, energy and minerals. Good quality clover hay has a similar nutrient value to lucerne hay and is much more palatable, but it is often hard to find.