放牧牛の生理・生態に関する研究(II-11) : Beat-meter法によって測定した放牧牛のエネルギー消費量の牧野による差異について

The energy expenditure measured indirectly by Beat-meter method was studied in early summer in 1963 and 1964 on the different conditioned pastures (improved pasture at Sambe in Shimane prefecture and woodland at Chiya in Okayama prefecture). Four cows (Japanese Black Breed of Cattle) were used in each experiment.
The results obtained are summarized as follows :
1. Although the representative value of heart rate in each behavior measured by Beat-meter method was a little higher than that by Stethoscope method that we had used up to this time, we believed that the most accurate heart rate was able to secure in this experiment. And the range of variation of heart rate in active behavior was especially wide as the cattle were grazed on woodland.
2. On the woodland, the heat production per kilogram per hour was obviously high in active behaviors. However, in static behaviors, it was much the same as on improved pasture.
3. The daily energy expenditure per kilogram of body weight in pasture grazing was more than in woodland grazing in static behaviors, and less in active ones.
The daily energy expenditure of lying form was more on pasture than on woodland, but that of standing form was less on pasture than on woodland. The heat production per kilogram of body weight for 24 hours was 40.46 Cal in average on pasture, and 42.00 Cal in average on woodland. It seems that about 4 per cent higher energy is consumed in woodland grazing than in pasture grazing.
4. The heat production per head per day of grazing cattle was about 13,500 Cal on pasture and 14,400 Cal on woodland, and these values were nearly same as the values previously reported by us with the aid of Stethoscope method.
From these points of view, we have been driven to conclude that the heat production of the grazing cow is in the range of 12,000-15,000 Cal per head per day.