牛の分娩前徴--尾の挙上回数の変化

概要

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The present study was undertaken to determine whether the frequency of tail movements during the preparturient period in cows could be utilized for the estimation of the onset time of parturition. Twelve Holstein cows held on public farms in Osaka Prefecture were used. Inspection was made on 30 (±5) and 15 (±3) days before the estimate time of parturition and every day from 7 days before to the day of term. The presence of tail movements with an angle higher than 60° and lasting more than 5 sec in duration was calculated by the equipment used for monitoring tail movements.The frequency of tail movements did not show significant change until day 1-2 before parturition, but the significant increase was detected from 1-2 to 0-1 days before parturition. In particular, the changing rate in the nocturnal activity was greater than that in the diurnal. A significant change in the nocturnal activity was detected between days 1 and 2 before parturition. In this activity, the frequency of tail movements exceeding 120 sec was less and did not show significant change throughout preparturition. The nocturnal frequency of tail movements lasting less than 120 sec before parturition was 34 on day 2 and 55 on day 1 per 12hr, respectively. These results suggest that the nocturnal frequency of tail movements lasting less than 120 sec may be worth noting for the prediction of the onset time of parturition.
社団法人日本畜産学会の論文