Rosebrough R W, Steele N C
Growth. 1985 Winter;49(4):479-89.
Male broiler chicks were fed diets containing 18, 23 or 30% protein on an ad libitum basis for 3 weeks. Chicks were also fed these diets on a restriction regime consisting of seven 3-day cycles (2 days with and 1 day without feed). Another group of chicks were fed diets containing 12, 23 or 30% protein on a 3-day rotation consisting of a daily change in dietary protein. Ad libitum. Feed intakes of chicks were inversely (P less than .05) related to the level of the dietary protein. Body composition data seemed to support a positive (P less than .05) relationship between dietary protein and total carcass protein and an inverse (P less than .05) relationship between dietary protein and carcass fat. In vitro lipogenesis was greater (P less than .05) in chicks fed an 18% protein diet than in chicks fed either 23 or 30% protein diets. Restricted. Protein levels had no effect on lipogenesis in chicks fed on a restriction regime but regulated lipogenesis in chicks fed on the rotational regime. Fatty acid synthetase, malic enzyme and isocitrate dehydrogenase activities, when measured during the rotational regime, were greatest following the 12% diet and least following the 30% diet. Enzyme activities, determined during the restriction regime, were greatest (P less than .05) after 1 day of refeeding and least (P less than .05) after 1 day of feed withdrawal. Measurement of net glucose production in vitro indicated that high-protein diets and feed withdrawal stimulated production of glucose.
雄性肉鸡雏鸡随意采食含18%、23%或30%蛋白质的日粮，持续3周。雏鸡也按照一种限饲方案采食这些日粮，该方案由7个3天周期组成（2天喂食和1天不喂食）。另一组雏鸡按照日粮蛋白质每日变化的3天轮换方案，采食含12%、23%或30%蛋白质的日粮。随意采食。雏鸡的采食量与日粮蛋白质水平呈负相关（P<0.05）。身体成分数据似乎支持日粮蛋白质与胴体总蛋白质之间呈正相关（P<0.05），以及日粮蛋白质与胴体脂肪之间呈负相关（P<0.05）。与采食23%或30%蛋白质日粮的雏鸡相比，采食18%蛋白质日粮的雏鸡体外脂肪生成量更多（P<0.05）。限饲。蛋白质水平对限饲方案下的雏鸡脂肪生成没有影响，但对轮换方案下的雏鸡脂肪生成有调节作用。在轮换方案期间测定时，脂肪酸合成酶、苹果酸酶和异柠檬酸脱氢酶的活性，在采食12%日粮后最高，在采食30%日粮后最低。在限饲方案期间测定的酶活性，在重新喂食1天后最高（P<0.05），在停止喂食1天后最低（P<0.05）。体外净葡萄糖生成量的测定表明，高蛋白日粮和停止喂食会刺激葡萄糖的生成。
