日粮不同蛋能比对黄羽黄鸡脂肪沉积和肠道酶活性影响

Effect of Dietary Crude Protein to Metabolizable Energy Ratios on Fat Deposition and Intestinal Digestive Enzyme Activity of Chinese Yellow Broilers

为研究不同蛋能比日粮对黄羽黄鸡脂肪沉积和肠道消化酶活性的影响,进行了2个试验。试验一（1~25d）选用1d改良型岭南黄鸡2000羽,随机分成4组,分别饲喂蛋能比（CMR）为15.63、16.13、16.50g/MJ和16.95g/MJ的日粮,每组5个重复,公、母混养;试验二（46~65d）选用46d黄鸡1920羽,随机分成4组,每组8个重复（公、母各4个）,日粮CMR分别为12.94、13.81、13.43g/MJ和13.61g/MJ。结果表明：25d时,各CMR水平对黄鸡皮脂厚度、胸肌和腿肌肌内脂肪含量无影响（P〉0.05）;65d时黄鸡腹脂重和腹脂率各组差异不显著（P〉0.05）,皮脂厚度第Ⅰ组比第Ⅳ组高84.73%（P〈0.05）,母鸡腿肌肌内脂肪含量第Ⅰ组比第Ⅳ组高93.49%（P〈0.05）。25d时黄鸡血清胆固醇和血糖水平无显著性差异（P〉0.05）,甘油三酯水平Ⅱ组显著降低（P〈0.05）;65d时公鸡血清胆固醇水平第Ⅱ组比第Ⅰ组高30.0%（P〈0.05）,母鸡各组间无显著性差异（P〉0.05）。25d时黄鸡小肠食糜内淀粉酶、胰蛋白酶和脂肪酶活性各组无显著性差异（P〉0.05）;65d时,母鸡3种酶活差异不显著（P〉0.05）,公鸡脂肪酶活性第Ⅰ组显著提高（P〈0.05）。综合分析各试验结果,黄鸡日粮中适宜蛋能比水平前期为16.13g/MJ;后期母鸡为13.43g/MJ,公鸡为12.94g/MJ。

Two trials were conducted to determine the effects of progressive dietary crude protein to metabolizable energy ratio （CMR） maintained at a constant CP concentration on fat deposition and intestinal digestive enzyme activity of lingnan yellow broilers in the starter phase（1-25d） and finisher phase（1-65d）,respectively.2000 birds in trial one were randomly divided into four groups and fed diets with 15.63,16.13,16.50 and 16.95 g/MJ CMR,respectively;In trial two,1920 birds were randomly divided into four groups and fed diets with CMR of 12.94,13.18,13.43 and 13.61 g/MJ.Birds sampled at the day of 25 in trial one and 65 in trial two.The results showed that,in trial two there were no significant difference in the weight and yield of abdominal fat and breast muscle.And the intramuscular fat content of females feeding group I diet was significantly higher than that of group IV （P〈0.05）.The serum triglyceride of birds in group II was increased in trial one and the serum cholesterol of male birds in group II was higher than that of group I （P〈0.05）.The activity of amylase,trypsinase and lipase of females had no significant difference in trial one,but activity of lipase of male birds in group I diets was significantly increased （P〈0.05） in trial two.According to the results,diet with CMR of 16.13 g/MJ in starter phase,14.73 g/MJ for female birds and 12.94 g/MJ for male birds in the finisher phase,respectively,were more benefit for the carcass and meat quality of Lingnan yellow broilers.