Physiological responses of dairy cows to fan plus sprinkler in holding pen.

摘要

This study was conducted to evaluate the effects of climatization (ventilation or ventilation and sprinkler) inside a holding pen in a milking parlour on the environmental parameters and physiological response of dairy cows. The 90-day experiment was conducted from August to October. 21 lactating dairy cows with an average milk yield of 21 kg/day were randomly allocated into 3 treatments: holding pen without cooling (control); holding pen with ventilation (V); and holding pen with ventilation plus sprinkler (VS). The physiological parameters measured in dairy cows were respiration rate (RR), body temperature (BT) and skin temperature (head, flank and mammary glands). Measurements were taken before and after each treatment. Environmental parameters such as dry bulb temperature (DBT), black globe temperature (BGT) and relative humidity (RH) were collected from each treatment session and from a meteorological station at a nearby site thrice a day. VS reduced the DBT (6.4 degrees C) and BGT (6.5 degrees C), but increased the RH. Both V and VS significantly decreased the RR. In the VS group, the skin temperatures of the head and flank were decreased by 4.2 and 2.8 degrees C, respectively. It was concluded that VS improved the environmental condition and physiological responses in cows. Moreover, it increased the heat loss of dairy cows.