裏山放牧和牛の行動とエネルギー消費量について

Abstract

Grazing behaviours and energy expenditure were studied in autumn with two cows (Japanese Black Breed) grazed on the mountain range(about 10 ha.) neighbouring the farm-house. The data gained in this experiment were compared with the results reported previously.
The results obtained were summarized as follows :
1. Both grazing hours and ruminating hours were a little longer, and resting hours and loafing hours were a little shorter than those of cows on the natural grass-land. The 24-hour histogram of grazing and ruminating time showed the typical autumn-type, being almost similar to that on the natural grass-land.
2. The walked distances during 24 hours were 3.25 and 4.87 km. in the two cows, respectively. These were about half as far as those on the natural grass-land.
3. The daily energy expenditure per kilogram of body weight was 15.64 kcal. in average ; it was about 80% of that on the natural grass-land. It was found that behaviours of grazing cows on the range neighbouring the farm-house were not so active as on the natural grass-land.
4. From these results, it was concluded that the cattle-grazing on the range neighbouring the farm-bouse was profitable from the viewpoint of grazing behaviours and energy expenditure.