N-乙酰半胱氨酸和冷应激对肉鸡肠道组织形态、能量代谢和抗氧化能力的影响

摘要

本试验旨在研究N-乙酰半胱氨酸(NAC)和冷应激对肉鸡肠道组织形态、能量状况和抗氧化能力的影响.试验将200只1日龄健康雄性科宝肉鸡随机分为4个处理组:对照组(基础日粮)、NAC组(基础日粮+0.1％NAC)、冷应激组(基础日粮)与冷应激+NAC组(基础日粮+0.1％NAC),每组5个重复,每个重复10只鸡.试验第1～2周按常规饲养方法控制温度,试验第3～6周冷应激组和冷应激+NAC组的温度控制在(10±2)℃,而对照组与NAC组维持在(26±2)℃.结果表明:冷应激处理使肉鸡平均日采食量、平均日增重、空肠低氧诱导因子1 (HIF-1) mRNA水平显著下降(P＜0.05),饲料转化率、回肠一磷酸腺苷(AMP)含量和空肠隐窝深度极显著升高(P＜0.01);日粮添加0.1％ NAC显著提高了冷应激肉鸡肠道绒毛高度(VH)、十二指肠与空肠绒毛高度与隐窝深度比值(VH/CD)、空肠三磷酸腺苷(ATP)和腺苷酸池(TAN)含量、回肠ATP和二磷酸腺苷(ADP)及能荷(AEC)含量、十二指肠超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活力、回肠谷胱甘肽过氧化物酶(GSH-Px)活力、空肠血红素加氧酶(HMOX) mRNA水平(P＜0.05).因此,日粮中添加0.1％的N-乙酰半胱氨酸可改善肠道组织形态和能量状况,提高冷应激肉鸡肠道抗氧化能力.%This experiment was conducted to investigate the effects of N-acetylcysteine (NAC) and cold stress on intestinal morphology,energy status and antioxidant capacity in broilers.The experiment was divided into 4 groups according to the factorial design (2 x 2).Two hundred 1-day-old male Cobb chickens were randomly divided into 4 groups:control group (basal diet),NAC group (basal diet + 0.1％ NAC),cold-stressed group (basal diet),and cold stress + NAC group (basal diet + 0.1％ NAC).Each group had 5 replicates with 10 chickens per replicate.The temperature form first to second week was controlled with conventional feeding management,whereas that from the third to sixth week in the cold-stressed and cold-stress + NAC groups was maintained at (10 ± 2)℃,which was differed with the other groups (26 ± 2)℃.The humidity was 50％～60％.The results showed that cold stress treatment decreased the broiler average daily feed intake (ADFI),average daily gain (ADG),and HIF-1 mRNA level in the jejunum (P＜0.05),whereas increased the feed conversion ratio (FCR),the level of AMP (P＜0.05),and crypt depth (CD) in the ileum and jejunum (P＜0.01) of broilers.Additionally,diet supplemented with 0.1％ NAC increased (P＜0.05) the intestinal villus height (VH),VH/CD in the duodenum and jejunum,the levels of ATP and TAN in the jejunum,the levels of ATE ADP,and AEC in the ileum,the activities of SOD and CAT in the duodenum,the GSH-Px activity and the HMOX mRNA level in the ileum of cold-stressed broilers.Taken together,diet supplemented with 0.1％ NAC could improve the intestinal morphology and energy status and increase the intestinal antioxidant capacity of cold-stressed broilers.