Onischuk L A, Kennedy A D
University of Manitoba, Winnipeg.
Domest Anim Endocrinol. 1990 Jul;7(3):365-81. doi: 10.1016/0739-7240(90)90042-x.
Two trials were conducted to determine the effect of compensatory growth on plasma glucose and serum growth hormone (GH), prolactin (PRL) and insulin concentrations in lambs. The trials consisted of a normal growth (NG) period (4 to 7 mo of age), a restricted feed/weight loss period and a compensatory growth (CG) period. The lambs in Trial 1 were 13 mo of age and in Trial 2, 11 mo of age at the start of the respective CG periods. Compensatory growth rate was 61 to 67% greater than NG rate in Trial 1 and 2, respectively. Twenty-four hour blood collections were performed during NG and CG in each trial. Normal growth blood collection for Trial 1 was performed in April (ram, n = 7; ewe, n = 6) and the CG blood collection in November (ram, n = 6; ewe, n = 6) while for Trial 2 blood collection dates were November (ram, n = 6; ewe n = 6) and March (ram, n = 4; ewe, n = 5). Trial 1 ram lambs had lower plasma glucose concentrations during CG than during NG while plasma glucose concentration was not altered in ewe lambs. Type of growth had no effect on plasma glucose in Trial 2. There was a type of growth by sex interaction for insulin in both Trial 1 and Trial 2. Insulin concentration decreased during CG in ram lambs but remained unchanged (Trial 1) or increased in ewe lambs (Trial 2) during CG. The effect of CG on PRL concentration in Trial 1 was confounded by photoperiod and the only effect in Trial 2 was a small decrease in the amplitude of PRL peaks during CG. The overall mean GH concentration (GHmn) was increased (P less than 0.01) two fold during CG in Trial 1. This effect was also seen in Trial 2 but the increase was sex dependent (P less than 0.005) with the effect of CG on GHmn in ram lambs being six times that seen in ewe lambs. The GH profile characteristics responsible for the increase in GHmn during CG differed between sexes and trials.
进行了两项试验，以确定代偿性生长对羔羊血浆葡萄糖、血清生长激素（GH）、催乳素（PRL）和胰岛素浓度的影响。试验包括正常生长（NG）期（4至7月龄）、限饲/体重减轻期和代偿性生长（CG）期。试验1中的羔羊在各自CG期开始时为13月龄，试验2中的羔羊为11月龄。试验1和试验2中，代偿性生长率分别比NG率高61%至67%。在每项试验的NG和CG期间进行24小时采血。试验1的正常生长采血于4月进行（公羊，n = 7；母羊，n = 6），CG采血于11月进行（公羊，n = 6；母羊，n = 6），而试验2的采血日期为11月（公羊，n = 6；母羊，n = 6）和3月（公羊，n = 4；母羊，n = 5）。试验1的公羊羔羊在CG期间的血浆葡萄糖浓度低于NG期间，而母羊羔羊的血浆葡萄糖浓度没有变化。试验2中生长类型对血浆葡萄糖没有影响。在试验1和试验2中，胰岛素均存在生长类型与性别的交互作用。公羊羔羊在CG期间胰岛素浓度降低，但母羊羔羊在CG期间胰岛素浓度保持不变（试验1）或升高（试验2）。试验1中CG对PRL浓度的影响受光周期混淆，试验2中唯一的影响是CG期间PRL峰值幅度略有下降。试验1中，CG期间总体平均GH浓度（GHmn）增加了两倍（P < 0.01）。试验2中也观察到了这种效应，但增加具有性别依赖性（P < 0.005），CG对公羊羔羊GHmn的影响是母羊羔羊的六倍。CG期间导致GHmn增加的GH谱特征在性别和试验之间存在差异。
