Digestible Energy Requirements for Exercising Horses

Abstract

Digestible energy required for maintenance and defined levels of exercise on an inclined treadmill was determined in a 4 × 4 Latin square experiment using four mature Quarter Horse geldings averaging 503 kg in body weight. All work was done at the same intensity (135 heart beats/min) and varied only in the frequency of forced exercise periods. Work (W) was defined as: W_kg-m = Wt_kg (D + D sine θ), where D = distance in meters. Horses were fed Coastal Bermudagrass hay at about .75% of body weight, and oats were fed at levels to maintain constant body weight. Digestible energy required to maintain the horses without forced exercise averaged 16.95 Mcal/d. During periods of forced exercise, mean daily digestible energy required to maintain the horses at constant body weight and corresponding total work loads were: 19.78 Meal at .89 × 10³ kg-km; 25.05 Meal at 1.80 x 10³ kg-km, and 28.22 Meal at 3.56 × 10³ kg-km. Digestible energy (DE) consumed during work periods was best described by the quadratic equation: DE_Mcal/d = 5.97 + .021 (Wt_kg) + 5.036X − .48X2, where X = work in kg-km X10³. Copyright © 1983. American Society of Animal Science . Copyright 1983 by American Society of Animal Science