Thermoregulatory Mechanisms of Jersey Adult Cattle and Calves Based on Different Body Sites Temperature

In this experiment six healthy adult dairy Jersey cattles and eight calves (aged 46 months) were selected to measure temperature of different body skin sites, rectal temperature, respiration and heart rates during summer and winter. Body sites maximum and minimum temperature in calves during summer belonged to the ear, forehead, right flank, abdomen (38.438.9 ˚C) and carpus (32 ˚C). This was also true for the foreleg, abdomen, tail (3838.15 ˚C) and tarsus (33.9 ˚C) of cattle, respectively. The minimum body temperature of all these animals was detected in the carpus and tarsus. Correlation coefficient was significant between rectal and tail temperatures (r=0.61; P 0.01). Also, there was significant correlation of respiration rate with abdomen, dewlap, neck, tail and rump temperature, but maximum coefficients were related to respiration rate with ear, forehead and tail temperature (r=0.80.91; P 0.01). Heart rate had maximum correlation with ear and forehead as well. It is concluded that both abdomen and tail and also other body sites, such as ear and neck, had significant role in body heat loss. Cattle heat dissipation to the environment is through the skin of their tail and ear and these have a higher correlation with respiration, heart rate and rectal temperature.