Gorewit R C, Svennersten K, Butler W R, Uvnäs-Moberg K
Department of Animal Science, New York State College of Agriculture and Life Science, Cornell University, Ithaca.
J Dairy Sci. 1992 Feb;75(2):443-8. doi: 10.3168/jds.S0022-0302(92)77780-7.
Plasma concentrations of oxytocin, prolactin, and cortisol were compared in five Swedish Red and White cows milked by hand versus machine. Cows were divided into two groups. One group was hand-milked; the other group was machine-milked. Treatments were switched every other day. The experiment was carried out for 6 d. Blood samples were taken prior to, during, and after milking and were assayed for hormones. More oxytocin and prolactin were released in hand-milked cows. There were no significant diurnal differences between the total amount of oxytocin released for the different treatments, but prolactin tended to be higher during hand-milking in the evening than in the morning milking. Cortisol concentrations were greater during hand-milking than during machine-milking. There were no significant treatment differences with regard to the total amount of cortisol released. During morning milking, cortisol concentrations were higher during hand-milking than during machine-milking. Our data show that hand-milking results in a pronounced and prolonged release of oxytocin and prolactin.
对5头瑞典红白奶牛分别进行手工挤奶和机器挤奶，比较了两种方式下血浆中催产素、催乳素和皮质醇的浓度。奶牛被分为两组。一组进行手工挤奶；另一组进行机器挤奶。每隔一天更换挤奶方式。实验持续6天。在挤奶前、挤奶期间和挤奶后采集血样，并检测其中的激素。手工挤奶的奶牛释放出更多的催产素和催乳素。不同挤奶方式下催产素释放总量没有显著的昼夜差异，但晚上手工挤奶时催乳素水平往往高于早上手工挤奶时。手工挤奶时皮质醇浓度高于机器挤奶时。不同挤奶方式下皮质醇释放总量没有显著差异。在早上挤奶时，手工挤奶时的皮质醇浓度高于机器挤奶时。我们的数据表明，手工挤奶会导致催产素和催乳素的显著且持续释放。
