To delay the onset of fatigue, endurance horses are often fed at rest stops during races. The resulting increase in blood insulin may adversely inhibit lipolysis. In humans, ingestion of fructose produces a smaller insulin rise than glucose. This study compared glucose and fructose as carbohydrate supplements for endurance horses.

To determine the effects of 3 rations (low grain, fat, high grain) on plasma creatine kinase (CK) activity and lactate concentration in Thoroughbred horses with recurrent exertional rhabdomyolysis (RER). Rations high in grain and formulated to exceed daily energy requirements may increase episodes of rhabdomyolysis in thoroughbred horses susceptible to RER.

High-grain diets for the exercising horse were compared with diets which provided 15% of the total caloric intake from either vegetable oil or a highly fermentable fibre source (beet pulp). Six Thoroughbreds age 3 years were fed one of 3 diets or 5 weeks in a replicated 3 x 3 Latin square.

There is considerable debate among horsemen about how to feed horses before exercise. Should horses be fed or fasted before work and when should hay be fed relative to grain and/or exercise? Three experiments were conducted to evaluate if feeding hay with and without grain affects glycaemic and haematological responses in Thoroughbred (TB) horses at rest and during a simulated competition exercise test (CET) on a high-speed treadmill.

Hoffman, R. M., L. A. Lawrence, D. S. Kronfeld, J. J. Dascanio and W. L. Cooper.1999. Dietary carbohydrates and fat influence radiographic bone mineral content of bones. J. Anim. Sci. 77:3330-33338. Abstract Hydrolyzable carbohydrate intake in horse diets may become excessive when rapidly growing pastures are supplemented with grain-based concentrates. The substitution of fat and […]

Previous studies have associated recurrent exertional rhabdomyolysis (RER) with a diet high in soluble carbohydrate (CHO). The purpose of this study was to investigate the effect of 3 diets on clinical and metabolic parameters in 5 Thoroughbred horses with RER and 3 healthy Thoroughbreds performing a standardised exercise test (SET). Two diets were formulated to meet energy requirements for the amount of exercise being performed in the form of CHO or fat (21.4 Mcal DE/day).

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.

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.

It has not been clearly established whether exercise affects digestibility. Therefore, it was the purpose of this study to measure the effect of 8 km daily trotting and galloping exercise on the digestibility and rate of passage of either an all-forage or a mixed forage/grain ration in trained Thoroughbred horses.