ホルスタイン種若齢去勢牛の肥育前期における人工草地放牧について

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"Four Holstein-Friesian steers, 220-day-old and 217 kg initial body weight on average, were used in order to investigate their body weight gain after being grazed on pasture and subsequently fed intensively in their housing. A three hundred-are (a) area of pasture dominated by Orchardgrass was divided into 7 paddocks was used for a 209-day grazing period consisting of 18 times of rotational utilization. The results are summerized as follows;
1. The forage yields of each paddock for the whole rotational utilization period were 211, 176 and 117 kg dry matter/10a; and the grazing periods were 3.3, 2.6 and 2.5 day/10a for spring, summer and autumn seasons, respectively.
2. The grazing efficiency of the pasture was very low during the spring season (28%), then it was raised during the summer (63%) and autumn (53%) seasons.
3. The mean daily weight gains of steers during the grazing periods were 0.68, 0.45 and 0.63 kg for spring, summer and autumn, respectively. However. the daily weight gain was calculated as 0.61 kg for the whole grazing period.
4. During the 58-day housing period after the steers were grazed on the pasture, the mean daily weight gain was calculated as l.31 kg. There was a tendency that the animal with low weight gain during the grazing period exhibits a relatively high weight gain during the housing period, and this would be a so called ""compensatory growth effect"".