The 7 Simple Rules of Equine Nutrition
Veterinary work often feels like working in a smash repair shop, constantly fixing problems after they occur. Common challenges veterinarians and owners face, such as stomach ulcers, colic, tying-up, laminitis, hoof conditions, leg and joint problems in growing horses, and performance issues, can be alleviated or even prevented with proper nutrition. Following a few simple rules can reduce many veterinary conditions and keep our horses stronger and healthier.
The simple rules of equine nutrition are:
Provide plenty of roughage/forage
Avoid high starch and high sugar feeds
Ensure good quality protein
Include oil in the diet
Supplement with Vitamin E
Add Biotin
Be cautious with supplements, as they can cause problems
Understanding the importance of high roughage, low-starch, quality protein, oil-enriched diets, Vitamin E, Biotin, and minimising multiple supplements can significantly enhance your horse's health. Let’s explore each of these simple rules in detail.
Rule 1: Provide plenty of roughage/forage
Hay, pasture, chaff, beet pulp, haylage, hulls, or other fibre sources are essential for horses. If not at pasture, horses and ponies need around 6kg of roughage daily for a 300kg pony, 8kg for a 400kg galloway, and 10kg for a 500kg horse. This helps prevent and heal stomach ulcers. Stomach ulcers can affect any horse at any age, with up to 90% of racehorses, 60% of show horses, non-performance horses and even foals affected by gastric ulcers. Spending six hours without roughage or forage increases the risk of stomach ulcers by four times. While medications can help ulcers heal, they can also reduce calcium absorption and other minerals. Several recent studies have shown that widely-prescribed anti-ulcer medications can significantly reduce calcium absorption from the intestine. Feeds and management are always cheaper and go a long way in healing and preventing ulcers.
Horses need constant and free access to some form of roughage. Saliva, which is very high in bicarbonate, helps neutralise the approximately 40 litres of stomach acid produced each day. Chewing produces saliva, and to eat 1kg of hay, horses make 3,000-3,500 chewing movements and produce up to 45 litres of saliva a day. Ponies make 5,000-8,000 chewing movements! In contrast, 1kg of concentrate or hard feed only requires 800-1,200 chews, resulting in less saliva and an increased risk of stomach ulcers. Horses only produce saliva when eating, but stomach acid is produced 24 hours a day. Even 4-6 hours without food can cause stomach ulcers. Including some lucerne in the diet is beneficial, as its high protein and calcium levels provide more acid-buffering, and horses fed lucerne have a lower risk of ulcers.
Rule 2: Avoid high starch & high sugar feeds
High starch and high sugar feeds increase the risk of stomach ulcers and gut acidosis, which can lead to colic and gut pain from acid, resulting in performance issues and 'hot' behaviour.
These feeds also cause fluctuations in blood sugar levels, which can lead to Equine Metabolic Syndrome (EMS), a disorder characterised by insulin resistance, obesity, and an increased risk of laminitis.
*Be aware that many 'cool' low-starch feeds are based on grain by-products such as millrun, bran, and pollard, which are actually high in starch and sugar.
See Table 1 for the starch, sugar and NSC % content of some commercially available feeds in Australia.
By choosing feeds low in starch and sugar, you can help maintain your horse's digestive health, regulate blood sugar levels, and support overall well-being.
Rule 3: Ensure good quality protein
Regardless of discipline, age, work level, or reproductive status, essential amino acids play a crucial role in maintaining hoof integrity, work capacity, body composition (muscle vs. fat), power-to-weight ratio, endurance, and reproductive health. High-quality protein sources such as lucerne, soy meal, and whey protein are rich in essential amino acids like lysine, methionine, threonine, and leucine. These amino acids are vital for building muscle, enhancing stamina, strengthening tendons, supporting bone health, and promoting red blood cell production.
Rule 4: Include oil in the diet
Adding oil to the diet provides numerous benefits for all horses, including improvements in acidosis, arthritis, behaviour, coat condition, fertility, inflammation, immunity, PSSM, vaccination response, skin health, temperament, and tying-up. Oils also offer owners an effective tool to maintain body condition in horses that lose their appetite under the stress of training, competition, and travelling.
Oil provides approximately three times as much energy as grains—330ml of oil delivers the same amount of energy as 1kg of oats—without the risk of 'hot' behavior and hind-gut acidosis (see Table 2).
Oils can also have a calming effect on excitable horses, including weanlings and those prone to tying-up. Horses on a 10% oil diet show reduced reactions to loud noise and visual stimuli; weanlings take less time to learn handling, and working horses exhibit fewer startle reactions when oils provide 11% of their dietary energy.
So, which oils should you choose?
Most diets are based on cereal grains, which are rich in omega-6 oils. In contrast, the natural diet of grazing and browsing horses is high in omega-3 oils. The Polyunsaturated Fatty Acids (PUFAs) in corn, sunflower, safflower, soy, and rice bran oil are mainly omega-6, which tend to aggravate inflammation. Oils with high omega-3 fatty acids, such as linseed, flaxseed, and fish oil, do not intensify inflammatory processes—in fact, they reduce them. Therefore, incorporating these omega-3-rich oils into your horse's diet can be highly beneficial (see Table 3).
Rule 5: Supplement with Vitamin E
Vitamin E is a powerful antioxidant that supports optimum performance and immune function. It is crucial in improving colostral IgG levels for new foals and enhancing the vaccination response in older horses. Unfortunately, most diets do not meet the minimum recommended daily intake of Vitamin E.
Rule 6: Add Biotin
Although a healthy horse gut synthesises most B-vitamins, including biotin, factors such as stress, travelling, competition, and stabling can reduce production and increase requirements. Many horses benefit from biotin supplementation, especially when combined with zinc and methionine, which together promote hoof wall growth and integrity.
Rule 7: Be cautious with supplements, as they can cause problems
Feeding multiple supplements can cause clinical and sub-clinical problems, which may not be visible but can significantly impact health and performance. In Australia, 60-77% of horse owners feed concentrate/manufactured feeds along with up to five (and sometimes ten!) additional supplements. This practice increases the risk of nutrient overlap and subclinical toxicity, with many horses being fed more than their dietary requirements, some even approaching maximum tolerable levels.
Jenquine all-4-feet® is ideal as a pasture/roughage balancer, addressing the mineral and protein deficiencies commonly found in all roughages and pastures. This is especially important if hays are soaked, as soaking increases mineral loss.
Jenquine all-4-feet® does not contain grains or by-products and is low in starch and sugar, making it suitable for horses with or at risk of stomach ulcers, insulin resistance (IR), laminitis, and Equine Metabolic Syndrome (EMS). It provides high-quality protein enriched with free-form amino acids and is high in Vitamin E. Additional supplements are not required when feeding Jenquine all-4-feet® at the correct feeding rates, except on veterinary advice.
Dr Jennifer Stewart
BVSc BSc PhD Equine Veterinarian and Consultant Nutritionist
