This study looked at the effect of feeding diets supplemented with either a predominantly saturated or unsaturated vegetable oil over a prolonged period to exercising horses. Eight Thoroughbred horses were assigned to 2 diet treatments and for 10 months were fed Timothy hay and oats, together with a fortified sweet feed supplemented with either a predominantly unsaturated (Un) or a saturated (S) vegetable oil so that approximately 19% DE (Digestible Energy) came from dietary fat and approximately 12% from either the Un or S source (AC). In conclusion, no apparent adverse effects of feeding a diet supplemented with either an unsaturated or saturated vegetable oil for 6 months at approximately 20% DE after 10 months at approximately 12% DE were identified and there were no apparent disadvantages of feeding a saturated vegetable oil supplemented diet compared with an unsaturated one.

MicroSteed takes the mystery out of horse diet evaluation Pagan JD , Huntington PJ Australian Equine Veterinarian 17(2), 88-91, 1999 Click here to access.

After water the major constituent of the horse’s body is protein. Eighty percent of the horse’s fat free, moisture free body composition is protein.

Carbohydrates are an extremely important part of a horse’s diet since about 75% of all plant matter is comprised of carbohydrates.

Horses have evolved over millions of years as grazers, with specialized digestive tracts to digest and utilize diets containing high levels of plant fiber.

Pagan, J.D. 1998. The incidence of developmental orthopedic disease (DOD) on a Kentucky Thoroughbred farm. In: J.D. Pagan (Ed.) Advances in Equine Nutrition. pp. 469-475. Nottingham University Press. Nottingham, United Kingdom. The incidence of developmental orthopedic disease on a commercial Thoroughbred farm was studied over a four-year period. A total of 271 foals were monitored. […]

Over a 3 year period a total of 350 thoroughbred colts and 350 thoroughbred fillies were weighed monthly on a portable electronic scale through 18 months of age.

Lactation places higher nutrient demands on the mare than any other stage of her life.

Harris, PA, JD Pagan, KG Crandell. 1998. Effect of feeding Thoroughbreds a high unsaturated or saturated vegetable oil supplemented diet for 6 months following a 10 month fat acclimatization diet. Proc. 5th International Conference on Equine Exercise Physiology. Utsunomiya, Japan.

Recent research demonstrated that feeding supplemented fat to Thoroughbred horses altered blood glucose and insulin levels compared to grain based diet and these changes influenced substrate selection during a standardized exercise test. It is unknown whether or not feeding time of the high fat diets would alter blood glucose and insulin response.