Study on Grazing Behaviour of Yaks in Summer, Autumn and Winter

The day-grazing behaviour of yaks was measured with visual observation method under free grazing in summer, autumn and winter pasture in Qinghai Sanjiaocheng Sheep Breeding Farm in August, September and November, 2004. The results showed that the average day-grazing time was (37.45±39.96) minutes in summer season, (301.82±27.91) min in autumn season and (304.57±12.24 )min in winter. The day-grazing time in summer pasture was the highest. The main reason was that the stocking rate was too high in summer pasture and there was no more forage for yaks to graze. The day-ruminating time in autumn and winter was (86.22±14.24) min and (53.84±13.93) min, respectively. The day-standing and walking time in autumn pasture was also higher than the other two seasons due to high forage productivity and quality. The weather wais cold and the forage was withered in winter pasture. Then the yaks spent more time in lying in winter.