Abstract
We examined total sweating rate (SR) and the amount of mineral (Na, K, Ca, Mg, Fe, P, Zn and Cu) loss through sweat in 2-year-old horses during exercise for approximately 2,000 m at a speed of 700 m/min, at cool ambient temperature. The total SR was estimated by the unit area SR on the neck by filter paper within a capsule. Mean total SR was 1.55 ± 0.47 (SD) kg. The ratio of sodium loss to the requirements reported by National Research Council reached 23% and that of potassium was 7%. The ratio of other mineral losses to the requirements reported by National Research Council was 2% or less. These results suggested that sodium had to be supplemented to the horse, but there was no need to add extra minerals to the diet to compensate for mineral losses of calcium, magnesium, iron, phosphorus, zinc and copper through sweat during exercise with light intensity and at a cool ambient temperature.
