Fontana E A, Weaver W D, Watkins B A, Denbow D M
Department of Poultry Science, Virginia Polytechnic Institute and State University, Blacksburg 24061-0332.
Poult Sci. 1993 Apr;72(4):684-90. doi: 10.3382/ps.0720684.
Four experiments were conducted to characterize the rates of lipogenic and lipolytic activities and the composition and DNA and RNA concentrations in muscle tissue of broilers that were feed restricted at an early age. In all experiments, feed restriction (40 kcal/day per bird) was initiated at 4 days of age with ad libitum consumption of feed resuming at either 11 (Experiments 1 and 2) or 10 (Experiments 3 and 4) days of age. Female chicks in Experiment 1 were feed restricted at the same level from 4 to 9 days of age. Birds consuming feed ad libitum served as controls in all experiments. Broilers restricted for 7 days had significantly lower plasma very low density plus low density lipoproteins (VLDL+LDL) than the ad libitum birds at 49 days of age in Experiments 1 and 2. However, the reverse was observed at 28 days of age, as plasma triglycerides and lipoproteins and lipogenesis were greater in restricted chicks when compared with controls. No significant differences were observed in plasma triglycerides at 49 days of age or lipolysis, DNA and RNA concentrations, muscle protein, and muscle fat at 28 days of age between restricted and ad libitum broilers. Results from these studies indicate that early feed restriction may have induced a metabolic shift in restricted broilers that increased lipogenesis at 28 days of age, followed by a partitioning of excess nutrients to support anabolic activity at market age.
进行了四项实验，以表征早期限饲肉鸡肌肉组织中脂肪生成和脂肪分解活性的速率以及其组成、DNA和RNA浓度。在所有实验中，4日龄开始限饲（每只鸡每天40千卡），11日龄（实验1和2）或10日龄（实验3和4）恢复自由采食。实验1中的雌性雏鸡在4至9日龄期间以相同水平限饲。所有实验中自由采食的鸡作为对照。在实验1和2中，限饲7天的肉鸡在49日龄时血浆极低密度脂蛋白加低密度脂蛋白（VLDL+LDL）显著低于自由采食的鸡。然而，在28日龄时观察到相反的情况，与对照相比，限饲雏鸡的血浆甘油三酯、脂蛋白和脂肪生成更高。限饲和自由采食的肉鸡在49日龄时的血浆甘油三酯或28日龄时的脂肪分解、DNA和RNA浓度、肌肉蛋白质和肌肉脂肪方面未观察到显著差异。这些研究结果表明，早期限饲可能诱导了限饲肉鸡的代谢转变，在28日龄时增加了脂肪生成，随后将多余的营养物质分配用于支持上市年龄时的合成代谢活动。
