Sticker L S, Thompson D L, Bunting L D, Fernandez J M
Department of Animal Science, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803, USA.
J Anim Sci. 1996 Jun;74(6):1326-35. doi: 10.2527/1996.7461326x.
Two diets consisting of bermudagrass hay and a corn-cottonseed hull-based supplement were formulated to provide either 100% (control) or 50% (restricted) of the protein and energy requirements for maintenance for mature mares. Twelve light horse mares were fed the control diet for 7 d, and then at 0800 on d 0, six mares were switched to the restricted diet. All diets were fed as two equally sized meals at 0800 and 1600. At 0800 on d 7, mares receiving the restricted diet were switched back to the control diet. Relative to control mares, mares switched to the restricted diet had reduced plasma concentrations of glucose (P = .005) and insulin (P = .09) in response to the two restricted meals on d 0. However, concentrations of both glucose and insulin returned to control levels (P > .1) within 1 h after the consumption of the control diet on d 7. Dietary restriction increased (P = .009) plasma NEFA concentrations within the first 24 h, and NEFA concentrations remained elevated (P < .001) in restricted mares until the mares were returned to the control diet on d 7. Meal-induced increases (P < .05) in plasma concentrations of glucose, insulin, urea N, glucagon, and thyroxine were observed. These results emphasize the importance of early sampling when monitoring plasma constituents during nutrient alterations and indicate that prefeeding responses of plasma constituents alone may not fully explain the metabolic consequences of nutrient restriction.
配制了两种日粮，一种以百慕大干草和玉米-棉籽壳为基础的补充料组成，分别提供维持成年母马所需蛋白质和能量的100%（对照）或50%（限制）。12匹轻挽马母马先饲喂对照日粮7天，然后在第0天的08:00，将6匹母马换成限制日粮。所有日粮均在08:00和16:00分成两顿等量饲喂。在第7天的08:00，接受限制日粮的母马换回对照日粮。与对照母马相比，换成限制日粮的母马在第0天对两顿限制日粮的反应中，血浆葡萄糖（P = 0.005）和胰岛素（P = 0.09）浓度降低。然而，在第7天食用对照日粮后1小时内，葡萄糖和胰岛素浓度均恢复到对照水平（P > 0.1）。日粮限制在最初24小时内使血浆非酯化脂肪酸（NEFA）浓度升高（P = 0.009），并且在限制组母马中，NEFA浓度一直升高（P < 0.001），直到第7天母马换回对照日粮。观察到进食引起血浆葡萄糖、胰岛素、尿素氮、胰高血糖素和甲状腺素浓度升高（P < 0.05）。这些结果强调了在营养改变期间监测血浆成分时早期采样的重要性，并表明仅血浆成分的预饲反应可能无法完全解释营养限制的代谢后果。
