Studies on Grass Productivity of Steep Mountainous Grassland : 1.Observations on the Grazing Behaviour of Young Steers of Japanese Black Breed

In June, August and October of 1966, observations were made on the grazing behaviour of young steers of Japanese Black breed of cattle on an improved pasture of steep mountainous grassland. The behaviour of the herd of ten steers was recorded at 5 min. intervals throughout 48 hr. and classified into grazing, eating concentrate, eating hay, ruminating, resting and walking. The day to day variation in behaviour varied with the trial period of the year, but a general similarity of grazing pattern was found in the two successive days within each trial period. In June, the grazing pattern was divided into three distinct periods: early in the morning, about midday and in the evening. In August, the pattern was divided into two periods: in the afternoon and at night. In October, there was one distinct period in the afternoon. RT/GT value varied seasonally from 1.2 in June to 1 in August and October. The hay eating time increased to three times as long as that of June in August and four times in October. Therefore, an increase in herbage intake in June and a reserve decrease both in August and October are clearly indicated.