Grazing behaviors of young fattening steers of Japanese Black Breed were observed every month from May to October on native grassland. Twelve grazing steers were divided into two groups; one group fed supplementary concentrates of 1.0-1.2 % and the other group fed 0.5-0.6 % of body weight daily.
The results obtained were summarized as follows :
1. Both grazing hours and ruminating hours of grazing steers, when fed the larger amount of supplements, were shorter than when fed the smaller amount of supplements.
2. In October, grazing hours of steers remarkably increased as compaired with other months.
3. Ruminating hours in each month of grazing steers generally changed in the same manner as the grazing hours.
4. Resting hours of grazing steers distinctly decreased in October.
5. Loafing hours seemed to be longer in the early stage of grazing period than in other stages.