Ambient temperature, calf intakes, and weight gains on preweaned dairy calves.

摘要

here has been little research conducted on the physiological response of calves to temperatures outside thermal neutrality and its effects on intake and weight gain. The effects of ambient temperature on Holstein dairy calves intakes and weight gain were evaluated over a 12-month period at the Utah State University Caine Dairy. Ambient temperature was monitored using a weather station located 1.3 kilometers from the dairy. Calf health was monitored daily using the University of Wisconsin-Madison School of Veterinary Medicine scoring criteria. Calves were fed whole milk and free choice calf starter. Weight gain, wither and hip height, starter intake, and weather data (temperature, wind speed, relative humidity, precipitation, and barometric pressure) were averaged for 7-day intervals beginning at birth through 13 weeks of age. A regression model was developed to describe the effects of starter intake, milk intake, hip and wither height, calf heath scores, and weather data on weight gain. The fall season (September, October, and November) had a negative impact on calf intake and weight gain (averaging 20 pounds (9.1 kilograms) less at 2 months of age) than other seasons. The delay in reaching the desired weight for calves raised in the fall season would cost a producer an extra