THE USE OF SOYA IN HORSE NUTRITION

 A considerable amount of the soya beans grown have the oil extracted for both human and animal use. The residue has about 46% protein and 1% oil, making it an extremely useful source of protein in high quality animal and human diets.

 Whole soya beans are also used extensively in the animal feed industry. After cooking and grinding, they are known as FULL FAT SOYA, which is supplied either in meal or pellet form. Typical analysis is 35% protein;17.5% oil; D.E. 18 MJ/Kg

The resulting product has a protein quality similar to that of egg-white, being relatively very rich in essential amino-acids such as LYSINE, METHIONINE, CYSTINE, THREONINE, TRYPTOPHAN, and ARGININE. Methionine and Cystine have a relatively high sulphur content and are therefore important in helping maintain healthy coats and hooves. Lysine is especially important for muscle growth and maintenance. Full fat soya is therefore an extremely useful product in mare and foal diets.

 Soya oil contains substantial amounts of LINOLEIC, LINOLENIC, and OLEIC (the Omega) fatty acids, essential for a horse's health, and particularly, skin and coat condition.

Soya oil has a digestible energy level about 3 times that of barley. It requires much more oxygen to release the energy in it compared with a similar amount of carbohydrate (e.g. starch). This process takes much longer, and so soya oil (in common with other fats and oils) provides a slow-release source of energy.

 The combination of high quality protein and oil makes Full - Fat Soya an ideal ingredient in diets for horses being asked to perform substantial work over long periods, for example activities such as eventing, hunting, endurance, draft work, dressage, riding schools, etc. It is invaluable in stud diets.

 The authors' first use of Full - Fat Soya occurred in about 1987. He had been supplying Horseheath Non-heating Mix to a customer whose 7/8 T.B. Hunter had previously, on a traditional oats/bran diet, frequently overtaken the hunt Master! The Non-heating Mix restored control, but at the cost of condition. As an experiment, a pound of Full - Fat Soya was added to the daily diet. This immediately gave more stamina and very soon restored condition; the rider retained control and was no longer subject to caustic comments from the Master!

Since then the author has used Full - Fat Soya extensively in the horse feed products which he has formulated and manufactured.

Full-fat soya has also been used successfully to keep toothless geriatric horses and ponies alive; it is normally fed with chaff (straw or alfalfa), soaked sugar beet pulp, and a mineral/vitamin supplement, all mixed to a porridge - like consistency. The ingredients do not need substantial chewing and are easily digested. Diets of this type can also be used where horses are allergic to feeds such as barley.

 Full - Fat Soya is not widely available through the retail feed trade because of its rather short shelf life (summer 4 weeks; winter 8 weeks). It is prone to attack by micro-organisms, Aspergillus species for example, which produce powerful mycotoxins (fungal poisons) such as Aflatoxin. Once incorporated into compound feeds, with suitable mould inhibitors, the shelf life is greatly extended.

Hipro Soya (the residual meal after the oil has been extracted) is however more widely available; the removal of the oil together with a lower moisture content make the product more stable, giving a much longer shelf life. Because of the higher protein content, Hipro is used at a lower rate than Full-fat soya, but will need balancing with a further supply of energy (e.g. from cereals or oil or fat).

 Gravenhorse Feeds can supply either form of soya direct to the more informed members of the equestrian fraternity (i.e. those who can be relied on to use it sensibly and not harm their horses).

John Chapman M.A. (Cantab)

Nutritionist, Gravenhorse Feeds.

May 2007