Heat Production of Jersey Dairy Cows Measured via IndirectCalorimetry

摘要

Currently available estimates of the heat production of lactating cows were generated more than 50 years ago. Since then, changes in dairy cattle due to genetics, nutrition and health regimens have led to significantly higher milk yield, which also makes it likely that heat production has increased. Therefore, the objective of the current study was to add information for use in updating estimated heat production of lactating Jersey cows. Data from headbox-style indirect calorimeters were pooled together across seven studies using 228 observations. In these studies, the average heat production was 1,109 ± 149 W or 11.4 ± 1.5W /kg071. This value provides an updated estimate of the heat production of a lactating Jersey cow that can inform the designof facilities for providing adequate ventilation and heat abatement to minimize heat stress.