Energy expenditure was measured in four geldings (433 to 520 kg) during submaximal exercise on a racetrack using a mobile open-circuit indirect respiration calorimeter. Total energy expended by the four horses walking, trotting, cantering was best described by the equation: Y = e3.02 + .0065X where Y = energy expended (cal X kg-1 X min-1) and X = speed (m/min).

Energy balance studies using indirect calorimetry were conducted with four mature equids ranging in weight from 125 to 856 kg. It was concluded that the maintenance requirements of equids vary linearly with body weight. The digestible energy (DE) requirement for equids confined to metabolism stalls was DE (kcal/d) = 975 + 21.28 X W where W equals body weight in kg.

This study was carried out to determine the metabolic response to load carrying and inclined trotting during treadmill exercise in the horse. Five standardbred trotters, trained for treadmill exercise, were subjected to an exercise test with and without 10% of their body weight in the position of a rider and saddle.

Three standardbred horses were used in a 3×3 Latin square design trial to determine the effect of feeding diets containing different levels of carbohydrate, fat, and protein to exercise horses. Muscle and live glycogen concentrations were significantly lower after the long slow exercise test when the horses were fed high protein and high fat than fed the commercial sweet feed diet.

Lawrence, L. A., E. A. Ott and S. N. Williams. 1986. Investigation of ultrasonic technique for prediction of bone mineral content. J. Anim. Sci. 63(Suppl. 1)215.

Lawrence, L. A. and E. L. Johnson. 1986. Developing proficiency in horse judging. J. Anim. Sci. 63 (Suppl. 1):215.

Miles, R. D., L. A. Lawrence, D. R. Campbell, F. S. Pipers and J. Brown. 1986. A comparison pf two non-invasive techniques to evaluate bone mineral status in Leghorn hens fed two dietary calcium levels. Poultry Sci. 65 (Suppl. 1):94.

Williams, S. N., L. A. Lawrence, L. R. McDowell amd N. S. Wilkinson. 1986. The influence of phosphorus level on mechanical properties of bovine bones. J. Anim. Sci. Sci. 63 (Suppl. 1):404.

Increases in energy intake decreased the concentration of total solids, protein, fat and gross energy of mare’s milk. Energy intake had a greater influence on the mare’s body condition than on milk energy production. It was concluded the objective of a feeding program for a lactating mare should be to keep the mare in a desirable body condition rather than to influence milk composition or production.

Williams, S. N., L. A. Lawrence, L. R. McDowell, and N.S. Wilkerson. 1986. The influence of phosphorus level on bone mineral content and bone strength in beef cattle. Proceedings of the Florida Beef Cattle Short Course. Gainesville, FL. 1986:1.