There are nearly as many theories about feeding horses as there are ideas on training.
Unfortunately, there is no strictly defined “right way” for either. Each horse is an individual, and their needs are dictated by breed, living conditions, build, work level, and age. So one feed does not fit all – at least not without some variation. Many factors come into play when deciding on a feeding programme.
For example, in New Zealand most horses, including racehorses, are at grass for at least some of the day – as opposed to their European and American counterparts who are confined to a stable while in full work. This gives a chance for exercise and extra grazing, if available. The same feeding programme under these conditions would not work as effectively in another country.
There are so many mixes and supplements available a horse owner could be forgiven for being confused about it all. Let’s get back to basics. What is all this stuff for, and what does it do?
(Note: this is not intended to be an exhaustive list, but rather a guide to the most common feeds).
From A to Zinc – a guide to feeds, supplements and minerals
Apple cider vinegar: claimed to reduce the risk of tying-up, repel flies and bots, reduce joint disease in growing horses, and improve general health. Contains electrolytes, potassium, and trace minerals.
Balage and Haylage: made from pasture that is fermented after it is harvested by sealing it in plastic wrap. Its feed value is related to the type of pasture used for making the haylage but is twice or three times higher thanmeadow hay. Limit intake to 300-400g/100kg body weight in each feed.
Barley: a common staple, its energy density 10% higher than oats on a weight basis, and almost 30% higher on a volume basis. By weight, its energy and protein content is midway between oats and corn. Boiling improves its digestion.
Bran: a byproduct of wheat flour milling. No significant laxative effect to horses because of their high fibre intake in hay and chaff. Contains useful levels of B-group vitamins, but low in most others.
Calcium (Ca): Aids in metabolism and essential to muscles. For strong bones and teeth, and helps with blood clotting. Deficiency signs include fragile bones and poor growth, and muscular problems.
Carrots: An appetiser. Chop into sections of 5mm thick rings before feeding to avoid choking.
Chaff: made from chopped lucerne or oat straw. Lucerne chaff has greater nutritional value than oaten chaff, which contains more roughage and bulk.
Chromium (Cr): Involved in carbohydrate metabolism and activity of insulin hormone. Common feed sources include brewer’s yeast.
Cobalt (Co): 4% cobalt is incorporated into structure in Vitamin B12, which is involved in haemoglobin formation and metabolism.
Cod Liver Oil: a source of Vitamin A and D.
Copper (Cu): performs biochemical and nutritional functions. Required for development of bone, joint cartilage, elastic connective tissue, utilisation of iron.
Copra Meal (Coconut meal): a “cool” energy feed because of its oil content (5-7%). It contains about 22% crude protein and from 12.5-16% crude fibre. Low lysine content; not suitable for growing horses. Use dry free-flowing copra meal, or dampen just before feeding.
Corn (maize): higher energy value than oats (18% more by weight, and twice as much by volume) but needs to be crushed or cracked as it will compact in the stomach, resulting in an overload of starch, which can lead to lactic acid build-up, which can cause laminitis and founder.
Cottonseed meal: Has a high protein content (20-41% depending on process); produced after cottonseed oil is extracted.
Dolomite: source of Magnesium sulfate. Also provides calcium.
Epsom salts: source of Magnesium sulfate. Has a laxative effect if given at dose rates of greater than 1 tablespoon/100kg bwt.
Fluorine (F): Incorporated in bone and teeth structure. Deficiency symptoms are not common if consuming fluoridated water, but can include excessive tooth wear, pain in the feet, and a dry, rough coat.
Garlic: a natural antibiotic and digestive aid, and for relief of respiratory problems.
Iodine (I): Most of this trace mineral is used to manufacture thyroxin in the thyroid gland. This hormone affects growth and metabolism. Signs of deficiency include goitre in mature horses, foals born weak or dead. Foals can develop enlarged joints and contracted tendons if excess is fed.
Iron (Fe): A component of every living organism – a horse’s body contains 33g iron /500kg.
Kelp (Seaweed): a source of iodine and many other trace minerals. Check the iodine content before adding kelp if other supplements such as iodised salt are also being given.
Linseed: a traditional coat conditioning and laxative feed for horses. Toxic unless crushed or boiled.
Lucerne: rich in protein, vitamin K, and many other vitamins and minerals.
Magnesium (Mg): Important for metabolism of calcium, Vitamin C, phosphorous, sodium and potassium. Found in dolomite.
Manganese (Mn): For bone growth and structure. Aids in the production of thyroxin (see Iodine), and in the manufacture of sex hormones and lactation. Signs of deficiency include large hocks and knuckling over of joints, brittle bones, foal death before or at birth, irregular seasons in mares. Too much can cause anaemia and infertility.
Milk Powder: a good quality protein source for foals and younger horses, but expensive. Contains about 50% lactose (milk sugar), which is not digested by mature horses over 4, because lactose enzyme activity is lost from the small intestine. In mature horses, amounts in excess of 150g/100kg body weight in a single feed can lead to low-grade diarrhoea due to the inability to break down lactose.
Molasses: widely added to feed as a sweetener. Contains energy in its sugar content, calcium and other trace-minerals, but not in sufficient amounts to be a useful source.
Oats: starch-based energy source; easiest of cereal grains for horses to chew, but lowest digestible energy concentration. High crude fibre content (10%) in the outer hull, which dilutes its starch content, helping to reduce the risk of digestive upset and laminitis if excess is fed relative to needs. Rolling or crushing does not significantly improve digestibility of its starch in the small intestine. Increased risk of “tying-up” and hyperactivity in some horses.
Peas: contain an average of 23% crude protein and a digestible energy content similar to barley. Low in fat (1%) and contain 6% crude fibre. Palatable when soaked or crushed.
Phosphorous (P): Present in every cell, and thought to play a role in all chemical reactions of the body. Essential to nerve functions, required for metabolism.
Pollard: The fine middlings of wheat milling; a conditioning feed, commonly used in Australia. Higher in energy and crude protein (17-18%) with 3.6% crude fat, but is lower in fibre than bran.
Potassium (K): an electrolyte that works with sodium to balance body fluids. (potash).
Salts: Sodium (Na), Chlorine (Cl), Common Salt (NaCl) Salts and electrolytes are essential to many functions. An endurance horse can lose up to 60 litres of sweat during a 160km endurance ride under warm and humid conditions. Heavy sweaters should be supplemented with potassium, magnesium and calcium. Potassium balances the salt levels and too much P results in salt deficiency.
Selenium (Se): Required as a trace-mineral and in combination with vitamin E acts as an antioxidant. Also part of an enzyme that regulates thyroxine hormone activity. Signs of deficiency include poor muscle development, White Muscle Disease in foals, poor performance, a predisposition to tying-up, and lower fertility in mares. Overuse can cause loss of hair of mane and tail, bent legs in foals, lameness and hoof separation.
Silage: like balage but stored in a pit. Up to 1kg/100kg body weight of sweet silage (moist weight) can be fed but horses won’t be interested in the wet, dark stuff.
Sodium bentonite: used as a binder in feed pelleting. The bentonite slows the digestive system and enables the animal to better utilise the feed nutrients.
Soya oil: coat conditioner and added source of added fat for extra energy. Contains phosphorous.
Soya bean meal: a byproduct of soy oil production. Contains the highest content of crude protein (44-45%) of any common oil seed meal. Provides a wide range of essential amino acids, and is a source of lysine, methionine, isoleucine, leucine, arginine, glycine and threonine.
Sugar Beet: A root vegetable used as a source of sugar for human consumption. Once the sugar is removed, fibre and pulp remains. Molasses is then added before it is dried and shredded or pelleted. Sugar beet is similar in energy value to oats but the energy comes from digestible fibre and not from starch, so making it less heating. Pellets should be soaked for up to 24 hours, and prepared fresh daily.
Sulphur (S): a key ingredient in protein, necessary for all basic body metabolisms. Found naturally in wheat germ.
Sunflower Seeds: energy, protein and coat conditioning feed for hard-working horses. Contain between 17-23% crude protein (due to their high oil content) and up to 26% oil and so are higher in energy than cereal grains.
Vegetable Oils: these provide a high-energy boost. Common seed oils used include corn, soyabean, sunflower, canola and blends of these oils. Omega-3 blends are considered to provide natural anti-inflammatory compounds and hormone action to improve the function and strength of blood vessels and body cells. It can take 6-8 weeks before a benefit is noticeable.
Wheat: not a common feed source for horses in New Zealand; primarily used for flour milling. If fed carefully and introduced slowly can be a useful energy grain. Energy density is slightly higher than corn by weight. Feeding more than 20% of it finely ground can lead to colic, so best fed cracked or coarsely ground.
Wheat germ: high phosphorous/calcium ratio, rich in B vitamins, iron, Vitamin E, copper, calcium, magnesium and manganese. A natural source of Sulphur.
Yeast: variable crude protein content, ranging from 40-51%, relative to their fermentation state and substrate. An expensive source of protein as compared to oil seed meals. Supplements based on this can aid in staggers.
Zinc (Zn): Assists in areas such as wound healing, growth and immunity.
Recommended reading: Feed Your Horse Like a Horse, by Juliet Getty
Feeding Horses in Australia – A Guide for Horse Owners and Managers; quoting sources: Tyznik (1982), NRC (1989), Caple (1991), Cunha (1991), Lewis (1995), Frape (1997); and Feeding and Nutrition of Horses: The Making of a Champion (JR Kohnke, Vetsearch International Aust, 1998); Racehorse training and feeding (Dr Philip Swann 1984); Natural Methods for Equine Health (Mary Bromiley, 1994).
First published in August, 2007