Effects of Air Movement on Respiration Rate,Heart Rate,Rectal Temperature,and Meat Production in Cattle

The study was designed to investigate the effect of air movement on respiration rate,heart rate and rectal temperature,using six Holstein steers,avereging 9 months of age and 375.0kg of body weight at the beginning of the study and 10 monhts and 402kg at the end.The investigation was carried out in the days in July and August when abbient temperature were over 28℃.Either cooled air using a pad-and-fan sysytem or natural air was sent by electric fan to the back of each steer from distributing hole of vinyl film duct set 1 meter upside from the back of cattle in the shelter.The fannig caused a decrease in heart rate and respiration rate,but not in rectal temperature.Decrease in ambient temperature also caused a decrease in respiration rate.On reduction of the respiration rate,the fanning in the study had the effect same with that of decrease in ambieit temparature as much as 4℃.Fannnig using the wet pad system was more effective on reduction of respiration rate than the fanning without the pad.Respiration rate had a positive correlation with dry bulb temperature and dry kata cooling power,and a negative correlation with wet kata cooling power.On the basis of the relation between heart rate and energy con-sumption,the effect of the fanninng beaf production was estimated.The fanning for 5 hours a steer economized energy equiv alent to the Calorie in 60 grams of beaf with standard quality at ambient temperature of 28-32℃,and of beef in above 32℃.