低蛋白质日粮对优质肉鸡屠宰性能及肌肉成分的影响

本试验旨在研究低蛋白质日粮对优质肉鸡屠宰性能及肌肉成分的影响。选取1980羽1日龄优质肉鸡（河田鸡）随机分为2个组，每组3个重复，每重复330羽。分1~28、 29~42、 43~75、76~105天等4个阶段饲养，每个阶段配制2种日粮，对照组日粮参照NY/T 33—2004《鸡饲养标准》中黄羽肉鸡的氨基酸模式及粗蛋白质水平，试验组日粮参照NRC(1994)肉仔鸡的氨基酸模式并在对照组的基础上降低粗蛋白质1个百分点，于105日龄进行屠宰分割、测定胸肌营养成分。结果表明：（1）两组间的半净膛率(PHE)、全净膛率(PE)、胸肌率(PBM)、腿肌率(PTM)、腹脂率(PAF) 、皮下脂肪(SFP) 、肌间脂肪(IMF)等差异均不显著(P＞0.05)；（2）两组间胸肌的水分、蛋白质、脂肪、氨基酸含量等差异均不显著(P＞0.05)。由此可见，降低日粮粗蛋白质1个百分点对优质肉鸡（河田鸡）的屠宰性能及肌肉成分无显著影响。

Effects of Low-Protein Diets on Slaughter Performance and Composition of Breast Meat of Chinese Color-feathered Chicken

This experiment was conducted to investigate the effects of low-protein diets on slaughter performance and composition of breast meat of Chinese color-feathered chicken. One thousand nine hundred and eighty one-day-old Chinese color-feathered chickens (Hetian Chickens) were randomly allocated to 2 groups with 3 replicates per group and 330 chickens per replicate. Chickens were fed with 4-phase (1-28d, 29-42d, 43-75d, 76-105d). Two diets were formulated for each phase. The control group fed diets with amino acid patterns and crude protein levels of Chinese color-feathered chicken according to NY/T 33-2004. The experimental group fed diets with amino acid patterns of broiler according to NRC (1994), but the crude protein levels were decreased 1 percentage based on the control diet, respectively. Chickens were slaughtered and mensurated composition of breast meat on 105-day-old. The results showed as follows: (1) There were no significant differences in percentage of half evisceration (PHE), percentage of evisceration (PE), percentage of breast meat yield (PBM), percentage of thigh meat yield (PTM), percentage of abdominal fat (PAF), subcutaneous fat pad(SFP), intermuscular fat(IMF) (P>0.05). (2) No significant differences in moisture, crude protein, ether extract and amino acid of breast meat were found between 2 groups (P>0.05). The results suggested that reducing dietary crude protein level 1 percentages have no significant effects on slaughter performance and composition of breast meat of Chinese color-feathered chicken.