Behavior and Ruminal Contraction of Japanese Black Cattle in the Summer Season

Abstract

A study was undertaken to determine the behavior time(eating, ruminating and repose), contraction of rumen and body temperature in the summer season. Cows were fed in paddock without shade (50m×50m), in paddock with shade (6m×6m)and in shed (3m×10m). In each group, quantity of solar radiant was l.2cal/cm2/min and environmental temperature was 29.2°C (highest) and 23.1°C (lowest). Body temperature was 38.8°C(highest) and 38.1°C (average) and 37.6°C (lowest) in each group. The amplitude of contract in internal pressure of the rumen at eating was higher in the paddock with shade group and shed group than in the paddock without shade group. The frequency of contract in internal pressure of the rumen at eating was not different in each group. Eating time was longer in the shed group than in the paddock without shade group and paddock with shade group(P<0.05).