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Studies on parturition in dairy cattle.

奶牛分娩的研究。

基本信息

批准号：
60560335
负责人：
MORI Junichi
金额：
$ 1.28万
依托单位：
Osaka Prefecture University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

项目摘要

Levels of estrone, estradiol-17 , progesterone and oxytocin in the peripheral plasma during late pregnancy and parturition in Holstein cows were measured. Estrone levels remained low until 4 weeks prepartum (155 pg/ml), began to rise from 4 weeks until 1 day prepartum (155-2271 pg/ml), and reached a peak at parturition. Then the levels fell to 197 pg/ml at 1 day postpartum. Changes in the plasma estradiol-17 levels generally resembled those for estrone levels, but the estradiol-17 levels were only 10-21% as compared to those of estrone levels. progesterone levels remained high until 2 days prepartum (o.71 ng/ml), began to fall at 1 day prepartum and 0.75 ng/ml at parturition, and was 0.23 ng/ml at 1 day postpartum. On the day of parturiton, the levels of estrogens and progesterone remained approximately constant from the beginning of opening labor pains until 1 hr postpartum. Oxytocin levels rose abruptly on the day of parturition in most of cows. The levels in cows showing weak pains were about half of those in normal cows.Changes in rectal temperature, heart and respiration rates, rising of tail head, and sizes of udder, teat and vulva were determined during the preparturient period in order to study these items could be utilized for the estimation of the onset time of parturiton. Fall in rectal temperature below 39.0゜C and marked increase of udder size was useful for the prediction of parturition time.Changes in behavior during preparturient period were also studied. Times of standing-up, standing time and tail movement were determined. These items may be worth noting as for the prediction of onset time of parturition.Effect of -adrenoceptor agonist (clenbuterol) on parturition time and uterine activity during parturition was examined in rats. After administration of -adrenoceptor agonist, the uterine contraction decreased and deriveries interrupted in rats. The efficacy of -adrenoceptor agonist was not so clear in cows.

测定了荷斯坦奶牛妊娠晚期和分娩时外周血浆中雌酮、17-雌二醇、孕酮和催产素的含量。雌酮水平在产后4周前一直很低（155 pg/ml），从产后4周开始升高（155-2271 pg/ml），并在分娩时达到高峰。然后在产后1天降至197 pg/ml。血浆雌二醇-17水平的变化通常与雌酮水平的变化相似，但雌二醇-17水平仅为雌酮水平的10-21%。孕激素水平在产后2天仍保持较高水平（0.71 ng/ml），产后1天开始下降，分娩时为0.75 ng/ml，产后1天为0.23 ng/ml。在分娩当天，雌激素和孕激素的水平保持大致恒定，从开始开放的阵痛，直到产后1小时。大部分奶牛催产素水平在分娩当天突然升高。本试验测定了泌乳期奶牛的直肠温度、心率、呼吸频率、尾头上升幅度、乳房、乳头和外阴大小等指标的变化，以研究这些指标可用于分娩开始时间的估计。直肠温度降至39.0 ℃以下和乳房体积显著增大对预测分娩时间有帮助，并研究了分娩临产期行为变化。测定小鼠的站立次数、站立时间和甩尾次数。这些项目可能是值得注意的，因为分娩的起始时间的prediction.Effect肾上腺素能受体激动剂（克伦特罗）对分娩时间和分娩过程中的子宫活动在大鼠进行了检查。给予肾上腺素能受体激动剂后，大鼠子宫收缩减弱，分娩中断。β-肾上腺素能受体激动剂在奶牛中的作用尚不清楚。