MINERAL BALANCE IN RESTING AND EXERCISED MINIATURE HORSES

Four mature Miniature Horse geldings were used in a study to measure m ineral losses from exercising horses. Mineral balance trials were cond ucted at rest and following workbouts after a four-week conditioning p eriod. During the second mineral balance trial, the extent of mineral loss in the sweat of the exercising horses was quantified. Minerals lo st in the sweat amounted to 1.8 g sodium, 3.9 g chloride, 5.9 g potass ium, 8.5 mg calcium, and 10.7 mg phosphorus per Meal DE consumed for w ork above maintenance. Dietary concentrations of calcium and phosphoru s were adequate to meet the needs of the exercising horses, but a need for sodium, potassium and chloride supplementation of the diet was in dicated. In this study, dietary requirements for Na, K and Cl during e xercise were increased over basal dietary supply by threefold, sevenfo ld, and sixfold, respectively.