半胱胺添加水平对黄羽肉鸡生长性能、肉质及机体抗氧化能力的影响

Effects of Cysteamine Supplementation Levels on Growth Performance,Meat Quality and Antioxidant Ability of Yellow Broilers

本试验在22～63日龄黄羽肉鸡日粮中添加不同水平的半胱胺，研究半胱胺对黄羽肉鸡生长性能、肉质及机体抗氧化能力的影响。选用750只21日龄黄羽肉鸡（母鸡）随机分为3组，每组5个重复，每个重复50只鸡。预饲1周后，在肉鸡基础日粮中分别添加0、60和120mg／kg半胱胺，鸡饲养至63日龄结束。结果表明，在黄羽肉鸡日粮中添加120mg／kg半胱胺可显著提高22-42日龄肉鸡的平均日增重和平均日采食量（P〈0．05），对22～42LI龄肉鸡的料重比及43-63日龄肉鸡的平均日增重、平均日采食量及料重比无显著影响（P〉0．05）；添加60mg／kg半胱胺可显著提高63日龄黄羽肉鸡肌肉pH45min、肌内脂肪含量和肌肉嫩度（P〈0．05），显著降低宰后45min肌肉亮度（L45min）（P〈0．05），添加60和120mg／kg半胱胺可显著提高63日龄黄羽肉鸡肌肉系水力（P〈0．05）；添加60mg／kg半胱胺可显著提高63日龄黄羽肉鸡血清和肌肉中谷胱甘肽含量（P〈0．05），显著提高肌肉中谷胱甘肽过氧化物酶的活性和总抗氧化能力（P〈0．05），肌肉中巯基含量有提高趋势，丙二醛含量有降低趋势；添加60mg／kg半胱胺可显著提高63日龄黄羽肉鸡肌肉中超氧化物歧化酶、谷胱甘肽过氧化物酶、腺苷-磷酸脱氨酶1、过氧化物酶体增生物激活受体-γ基因的表达（P〈0．05）。结果提示：在22～63日龄黄羽肉鸡日粮中添加120mg／kg半胱胺能显著提高22-42日龄鸡的生长性能（P〈0．05）；在22-63日龄黄羽肉鸡日粮中添加60mg／kg半胱胺能显著提高63日龄鸡的肌内脂肪含量、肌肉嫩度、肌肉pH及系水力，提高机体抗氧化能力（P〈0．05）。

The study was conducted to investigate the effects of different levels of cysteamine supplementation in basal diets on growth performance, meat quality and antioxidant ability of yellow broilers. Seven hundred and fifty yellow broilers at the age of 21 d were selected and allotted to 3 groups in a random design. Each group consisted of 5 replicates with 50 broilers in each replicate. After pre-feeding for 1 week, broilers were fed diets supplemented with 0, 60 and 120 mg/kg cysteamine, respectively, and the experiment was finished when the broilers grew to 63 d. The results showed that dietary supplemented with 120 mg of cysteamine per kg diets increased the average daily gain （ADG） and average daily feed intake （ADFI） of broilers at 22-42 d old （P〈0.05） ,but did not affect the feed to gain ratio （F/G） of broilers at 22-42 d old and the ADG, ADFI and F/G of broilers at 43-63 d old（P〉0.05）. Supplementation with 60 mg/kg cysteamine increased pH45 min, intramuscular fat content and tenderness of muscle in broilers about 63 d old, and also decreased lightness （L45min） of muscle （P〈0. 05）. Supplementation with 60 and 120 mg/kg cystcamine increased water-holding capacity of muscle in broilers at 63 d old （P〈0.05）. Glutathione content in serum and muscle, glutathione peroxidase （GSH-Px） activity and total antioxidant ability in muscle of broilers at 63 d old were also increased by supplemented with 60 mg/kg cysteamine （P〈0.05）. Supplementation with 60 mg/kg cysteamine had a trend to increase the hydrosulphonyl content and tend to decrease the malondialdehyde content. Supplementation with 60 mg/kg cysteamine increased the superoxide dismutase, GSH-Px, adenosine monophosphate deaminase 1 and peroxisome proliferator-activated receptor-γ gene expression in muscle of broilers at 63 d old. In conclusion, supplementation with 120 mg/kg cysteamine in diets of broilers at 22-63 d old increased the growth performance of broilers at 22-42 d old; and supplementation with 60 mg/kg cysteamine in diets improved the water-holding capacity, intramuscular fat content, tenderness and pH of muscle and antioxidant ability of broilers at 63 d old.