Exercise Affects Digestibility And Rate Of Passage Of All-forage And Mixed Diets In Thoroughbred Horses
Pagan, J.D., P. Harris, T. Brewster-Barnes, S.E. Duren and S.G. Jackson. 1998. Exercise affects digestibility and rate of passage of all-forage and mixed diets in Thoroughbred horses. Journal of Nutrition, 128:12S, pp. 2704S-2707S.
Abstract
Most digestibility studies in horses have been conducted with idle horses confined to metabolism stalls. The values obtained from such studies are used for all classes of horses, including the performance horse. It has not been clearly established whether exercise affects digestibility. Olsson and Ruudvere (1955), summarizing a number of earlier studies, suggested that digestion may be affected in horses by work or exercise in such a way that it is improved by light exercise and inhibited by heavy work.
Orton et al. (1985) reported reduced retention time of a particulate marker in yearling horses trotting 12 km/d. However, apparent digestibility and retention of a fluid marker were increased with exercise. These discrepancies raise questions concerning the effect of exercise on digestibility and rate of passage in older, physically fit horses. 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.