日粮蛋白质对7～12周龄略阳乌鸡生长发育的影响

通过分析日粮蛋白质对7～12周龄略阳乌鸡生长性能、主要组织器官发育和血清生化指标的影响,初步确定此阶段略阳乌鸡蛋白质的需要量。选取600只43日龄略阳乌鸡,随机分为5组,每组6个重复,每个重复20只鸡(公母各半),5个组分别饲喂蛋白质质量分数为12.39%、14.20%、16.60%、18.06%和20.15%的日粮。结果表明,日粮蛋白质质量分数对略阳乌鸡的平均日增量、料质量比、胰腺、胸腺和法氏囊质量、胸肉占体质量的比例及血清中白蛋白质量浓度均有显著影响,对平均日采食量、部分内脏器官指数和血清生化指标无显著影响,饲喂日粮蛋白质质量分数为18.06%和16.60%处理组的略阳乌鸡平均日增质量、料质量比、胸肉占体质量的比例及血清中白蛋白质量浓度显著高于12.39%、14.20%和20.15%处理组。随着日粮蛋白质质量分数的增加,平均日增量及料质量比都呈现二次曲线变化趋势。回归分析表明,以平均日增量及料质量比为评价指标,7～12周龄略阳乌鸡日粮蛋白质需要量分别为17.52%和17.18%。

Effects of Dietary Protein on Gowth and Development in Lueyang Black-boned Chickens from Seven to Twelve Weeks of Age

This study was to evaluate the effect of dietary protein mass farction on growth performance,main tissue or organs development and serum biochemical indexes in order to determine the optimum requirement of protein for 7-12-week-aged Lueyang black-boned chicks.A total of 600 forty-two-day-old Lueyang black-boned chicks were randomly assigned to five treatments,each treatment contained 6 replications with 10 males and 10 females.The birds fed experimental diets with the same metabolizable energy (12.34 MJ/kg) and different protein mass farction of 12.39%,14.20%,16.60%,18.06% and 20.15% from 7 to 12 weeks of age respectively.The result showed that dietary protein mass fraction had significant influence on the average daily gain,feed conversion ratio,pancreas and thymus and bursa of fabricius mass ,chest meat to body mass ratio and the mass mass fraction of serum albumin were significantly influenced by dietary protein mass farction ,except the feed intake,other visceral organ indexes and biochemical indexes.The birds fed the diet with 18.06% or 16.60% dietary protein exhibited greater in growth rate,feed conversion rate,proportional breast mass and albumin mass concentration in serum than that of those fed other dietary protein mass farction.Growth rate and feed conversion rate indicate a tendency to quadratic curve with increase in dietary protein mass farction .Based on the results of regression analysis,the CP requirement of Lueyang black-boned chicken from 7 to 12 weeks of age for optimal mass gain and feed-gain ratio was 17.52% and 17.18%,respectively.