放牧牛の生理・生態に関する研究(II-9) : 原野放牧中の和牛・乳牛・馬のエネルギー消費量について

The differences of energy expenditure among Japanese Black Breed of Cattle(Wagyu), dairy heifer and mare were studied while they were grazing in summer on Sasagamine Range in Niigata Prefecture.
The energy expenditure was estimated by the indirect method previously reported on by us.
The principal results obtained were as follows :
1. Daily heat production per kilogram of body weight was about 35 Cal. in cattle, and it seems that the dairy heifer consumes a little more energy than Japanese Black Breed of Cattle in grazing and ruminating forms.
2. The mare consumed a large amount of energy ─ especially in grazing, standing-in-rest and migrating forms. The total heat production of mare was about 100 Cal. per kg. per day, and was about three times as much as that of cattle. This large energy expenditure seems to result from the fact that, though the heart rate of horse is lower than that of cattle in every behaviour, the increasing rate of R.M.R. of horse is far greater than that of cattle. (cf. Fig. 4)
3. It was found in this study that the more energy is produced from the forage on the range, the less distance is walked and the less energy is expended by the grazing cattle.