Ohlson D L, Davis S L, Ferrell C L, Jenkins T G
J Anim Sci. 1981 Aug;53(2):371-5. doi: 10.2527/jas1981.532371x.
An experiment was conducted to test the hypothesis that bull calves of a larger, faster growing breed of cattle exhibit greater secretory activity of anabolic pituitary hormones than bull calves of a smaller, slower growing breed. Calves of both breeds were raised under similar conditions and maintained on the same diet for approximately 4 weeks before the blood sampling period. Simmental bull calves had higher (P less than .01) average daily gains and a heavier (P less than .01) mean body weight than Hereford bull calves. Overall plasma growth hormone (GH) concentrations were higher (P less than .01) in Simmental bull calves than in Hereford bull calves. Mean baseline GH was also higher (P less than .05) in Simmentals. Overall and baseline concentrations of prolactin (PRL) were similar for both breeds. Mean amplitude of PRL secretory spikes was higher (P less than .05) for Simmental than for Hereford bull calves. There was no breed effect on any variable of thyrotropin secretion. These data suggest that representatives of a larger, faster growing breed of cattle (Simmental) exhibit greater secretory activity of GH and PRL than do representatives of a smaller, slower growing breed (Hereford).
进行了一项实验，以检验这样一个假设：体型较大、生长较快的肉牛品种的公牛犊，其垂体合成代谢激素的分泌活性要高于体型较小、生长较慢的肉牛品种的公牛犊。在采血期之前，两个品种的牛犊均在相似条件下饲养，并维持相同的饮食约4周。西门塔尔公牛犊的平均日增重更高（P小于0.01），平均体重也更重（P小于0.01），高于海福特公牛犊。西门塔尔公牛犊的血浆生长激素（GH）总体浓度高于海福特公牛犊（P小于0.01）。西门塔尔牛的平均基础GH也更高（P小于0.05）。两个品种的催乳素（PRL）总体浓度和基础浓度相似。西门塔尔公牛犊的PRL分泌峰值平均幅度高于海福特公牛犊（P小于0.05）。促甲状腺激素分泌的任何变量均无品种效应。这些数据表明，体型较大、生长较快的肉牛品种（西门塔尔牛）的代表，其GH和PRL的分泌活性高于体型较小、生长较慢的肉牛品种（海福特牛）的代表。
