放牧牛の生理・生態に関する研究(I-9) : 春放牧期間における和牛の行動の変化について

Grazing behaviors of Japanese Black Breed cows, in each stage of the spring grazing period from May to July, were studied on Sambe native grassland in Shimane Prefecture. The constant observations of grazing cows for 24 hours were made every other day from the beginning of grazing to the 8th day, and thereafter at about ten days' intervals. At the housing periods, immediately before and after the grazing period, we also observed the behaviors of the cows.
The results obtained are summerized as follows ;
1. Both grazing hours and ruminating hours of the cows on range increased to about two times, as compared with those hours of the cows in barn. But resting hours of the cows on range decreased to about a half of the hours in barn.
2. The time spent by the cows on range was shorter in grazing and ruminating forms, and was longer in loafing and migrating forms, in the early stage of spring grazing period than in the subsequent stages. Walked distances of the grazing cows were also longer in the earlier stage.
3. The time spent by the cows in each behaviors did not differ according to weather. But hour to hour changes of a day in the grazing and ruminating time, the rate of lying and standing hours and the locations of the cows differed much according to weather.