Peel C J, Fronk T J, Bauman D E, Gorewit R C
J Nutr. 1982 Sep;112(9):1770-8. doi: 10.1093/jn/112.9.1770.
Milk production responses to 1) growth hormone injections (51.5 IU/day), 2) a mixture of glucose (274 g/day) and sodium caseinate (441 g/day) infused into the abomasum, 3) a combination treatment, and 4) a placebo treatment were determined in 4 cows in a 4 x 4 Latin square design. Treatment periods were 10 days, and production responses were based on the last 5 days of each treatment. Growth hormone administration increased milk yield 15.2% without changing milk composition or feed intake. Infusions of glucose-sodium caseinate into the abomasum increased milk yield 3.9% and milk protein yield 6.4% but when combined with growth hormone treatment did not stimulate a greater response than observed for growth hormone alone. Plasma concentrations of growth hormone were increased 4-fold with growth hormone injections but were not affected by the infusion of glucose-sodium caseinate into the abomasum. There were no significant changes in plasma concentrations of glucose, free fatty acids, insulin, glucagon, prolactin, triiodothyronine, thyroxine or cortisol with any of the treatments. Growth hormone increased milk synthesis and the efficiency of milk production, but its effect was not enhanced by the postruminal supply of additional nutrients.
采用4×4拉丁方设计，对4头奶牛测定了以下4种处理对产奶量的影响：1）注射生长激素（51.5国际单位/天）；2）向皱胃灌注葡萄糖（274克/天）和酪蛋白酸钠（441克/天）的混合物；3）联合处理；4）安慰剂处理。处理期为10天，产奶量反应基于每种处理的最后5天。施用生长激素可使产奶量提高15.2%，而不改变乳成分或采食量。向皱胃灌注葡萄糖 - 酪蛋白酸钠可使产奶量提高3.9%，乳蛋白产量提高6.4%，但与生长激素处理联合使用时，并未比单独使用生长激素刺激出更大的反应。注射生长激素可使血浆生长激素浓度增加4倍，但向皱胃灌注葡萄糖 - 酪蛋白酸钠对其无影响。任何处理均未使血浆葡萄糖、游离脂肪酸、胰岛素、胰高血糖素、催乳素、三碘甲状腺原氨酸、甲状腺素或皮质醇浓度发生显著变化。生长激素可提高乳合成和产奶效率，但瘤胃后补充额外营养并不能增强其效果。
