Stanton H C, Mueller R L
Am J Vet Res. 1976 Jul;37(7):779-83.
Three litters of pigs were weaned at 21 days of age, and 3 others were left with the sow. Pigs were killed at 21, 23, 28, or 39 days of age. Weaned pigs exhibited anxiety, gastrointestinal dysfunction, and decreased rate of body weight gain. Plasma glucose or liver glycogen concentrations were not decreased by weaning. Adrenal gland weights and tyrosine hydroxylase (EC 1.14.3a), dopamine beta-hydroxylase (EC 1.14.2.1), phenethanolamine-N-methyl transferase (EC 2.1.1), and monoamine oxidase (EC 1.4.3.4) activities were increased after weaning. Adrenal catecholamine and cortisol levels and dopa decarboxylase (EC 4.1.1.26) and catechol-o-methyl transferase (EC 2.1.1.6) activities were not significantly altered, although some increases were indicated. Cranial cervical ganglionic choline acetyltransferase (EC 2.3.1.6) and tyrosine hydroxylase activities were increased after weaning. Weaning of swine at 21 days of age is a stressful experience, and many effects persist for at least 18 days; however, growth was no longer impaired 18 days after weaning.
三窝仔猪在21日龄时断奶，另外三窝则继续由母猪哺育。仔猪在21、23、28或39日龄时被宰杀。断奶仔猪表现出焦虑、胃肠功能紊乱以及体重增加速率下降。断奶并未使血浆葡萄糖或肝糖原浓度降低。断奶后肾上腺重量以及酪氨酸羟化酶（EC 1.14.3a）、多巴胺β-羟化酶（EC 1.14.2.1）、苯乙醇胺-N-甲基转移酶（EC 2.1.1）和单胺氧化酶（EC 1.4.3.4）的活性增加。肾上腺儿茶酚胺和皮质醇水平以及多巴脱羧酶（EC 4.1.1.26）和儿茶酚-O-甲基转移酶（EC 2.1.1.6）的活性虽有一些升高迹象，但未显著改变。断奶后颈上神经节胆碱乙酰转移酶（EC 2.3.1.6）和酪氨酸羟化酶的活性增加。21日龄时对仔猪进行断奶是一种应激经历，许多影响至少持续18天；然而，断奶18天后生长不再受到损害。
