Effects of pasture season on the body temperature, steps-taken, and body weight of Japanese black cows

Abstract

Understanding the physiological condition of grazing cows according to the season is effective for proper feeding management. To clarify the effects of season, this study investigated differences between spring and summer on the body temperature, steps-taken, and body weight of Japanese black cows. The pasture periods were 7 days in both seasons. The amount of grass was measured before and after pasture. The same 5 non-pregnant, non-nursing cows were used in both seasons. The body (vaginal) temperature was recorded using a data-logger attached to a CIDR. A pedometer was attached to the foreleg to measure the number of steps taken. To calculate the body weight gain, each cow’s body weight was measured before and after pasture. The body temperature fluctuations were different between seasons. The body temperature and steps-taken during pasture were significantly higher in spring than summer (P<0.01). There was a significant negative relation between the number of steps taken and the body weight gain (P<0.05). In conclusion, the amount and quality of grass in the pasture differed due to the pasture season, and it is possible that the increase in steps-taken was due to walking around the pasture looking for grass. Moreover, it was suggested that the increased number of steps-taken caused the seasonal difference in body temperature fluctuations.