SUPPLEMENTAL SHADE FOR DAIRY CALVES REARED IN COMMERCIAL CALF HUTCHESIN A SOUTHERN CLIMATE

Two studies were conducted during consecutive years to determine the e ffects of providing supplemental shade to dairy calves reared in comme rcial hutches made of translucent plastic in a southern environment. C alves were assigned at birth to polyethylene calf hutches located in e ither an open control area or under supplemental shade (n = 9 to 12 pe r group per year). Shade reduced temperatures both inside the hutches and in the outer exercise areas during both years. However, shade incr eased humidity in the exercise area during yr 1. Shaded calves had low er rectal temperatures than control calves during yr 1, but difference s were not significant during yr 2. Shade did not alter plasma cortiso l concentrations. Shaded calves consumed less concentrate feed but had average daily gains that were similar to those of control calves, res ulting in a tendency for greater feed efficiency for shaded calves. Co unts for both total and fecal coliforms were greater in bedding collec ted from hutches under supplemental shade, but there was no difference in the incidence of health disorders. Providing supplemental shade to calves reared in plastic hutches in a warm southern environment alter ed the calf environment in a predictable manner but had little effect on overall growth and health.