Sticker L S, Thompson D L, Bunting L D, Fernandez J M, DePew C L, Nadal M R
Department of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge 70803, USA.
J Anim Sci. 1995 Dec;73(12):3696-704. doi: 10.2527/1995.73123696x.
Twelve light horse mares were fed a control diet that provided 100% of their maintenance protein and energy requirements for 7 d and were then either continued on the control diet or totally deprived of feed (with access to water) for 3 d . Plasma samples were drawn twice daily throughout the experiment, at 15-min intervals for 9 h beginning 45 h after feed removal, and at 10-min intervals around an exercise bout beginning 73 h after feed removal. Feed deprivation increased (P < or = .06) whole blood beta-hydroxybutyrate and plasma NEFA, urea N, L-lactate, and glucagon concentrations, decreased (P = .02) IGF-I concentrations, and did not change (P > .1) plasma glucose insulin, prolactin, triiodothyronine, and thyroxine concentrations. Exercise increased (P < .05) plasma NEFA, prolactin, and growth hormone (GH) concentrations in all mares. Plasma NEFA concentrations increased (P < .001) after exercise and remained increased in fed mares, but rapidly decreased in deprived mares (time x diet interaction, P = .006). Plasma glucose concentrations following exercise increased in deprived mares but decreased in fed mares (time x diet interaction, P = .07). The plasma prolactin response after exercise also differed between groups (P = .09). Feed-deprived mares had greater (P = .02) plasma GH concentrations before exercise (73 h after feed withdrawal) and had a greater (P < .001) GH peak at 10 min after initiation of exercise. The increase in secretion rate o GH due to feed deprivation in these mares was similar to that reported for other domestic species but was not nearly as great in magnitude.
12匹轻挽母马被给予一种对照日粮，该日粮提供其维持所需蛋白质和能量的100%，持续7天，然后要么继续给予对照日粮，要么完全剥夺饲料（可饮水）3天。在整个实验过程中，每天采集两次血浆样本，在撤除饲料45小时后开始，以15分钟的间隔持续9小时，在撤除饲料73小时后开始，围绕一次运动 bout 以10分钟的间隔采集。饲料剥夺使全血β-羟基丁酸、血浆非酯化脂肪酸（NEFA）、尿素氮、L-乳酸和胰高血糖素浓度升高（P≤0.06），使胰岛素样生长因子-I（IGF-I）浓度降低（P = 0.02），而血浆葡萄糖、胰岛素、催乳素、三碘甲状腺原氨酸和甲状腺素浓度未发生变化（P＞0.1）。运动使所有母马的血浆NEFA、催乳素和生长激素（GH）浓度升高（P＜0.05）。运动后血浆NEFA浓度升高（P＜0.001），在采食母马中保持升高，但在饥饿母马中迅速下降（时间×日粮交互作用，P = 0.006）。运动后饥饿母马的血浆葡萄糖浓度升高，而采食母马的血浆葡萄糖浓度降低（时间×日粮交互作用，P = 0.07）。运动后血浆催乳素反应在两组间也存在差异（P = 0.09）。饥饿母马在运动前（撤除饲料73小时后）的血浆GH浓度更高（P = 0.02），且在运动开始后10分钟时GH峰值更高（P＜0.001）。这些母马因饲料剥夺导致的GH分泌率增加与其他家养物种报道的相似，但幅度没有那么大。
