复合酶与枯草芽孢杆菌对黄羽肉鸡生长性能、肉品质和肝脏功能的影响

Effects of Complex Enzymes and Bacillus subtilis on Growth Performance,Meat Quality and Liver Function of Yellow-feathered Broilers

【目的】研究复合酶与枯草芽孢杆菌对黄羽肉鸡生长性能、肉品质和肝脏功能的影响。【方法】选用1 200只1日龄快大型黄羽肉公鸡,随机分为5组,每组6个重复,每个重复40只鸡。对照组饲喂基础饲粮,其他组依次在基础饲粮中添加20 mg/kg维吉尼亚霉素(抗生素组)、500 mg/kg复合酶(复合酶组)、200 mg/kg枯草芽孢杆菌(枯草芽孢杆菌组)以及500 mg/kg复合酶+200 mg/kg枯草芽孢杆菌(联用组),试验期63 d。分别于21、42和63日龄以重复为单位对肉鸡空腹称重并统计采食量,计算生长性能;21和63日龄从每个重复选取2只鸡屠宰,收集血液和肝脏组织样品,测定生化指标;21日龄收集盲肠内容物测定菌群数量;63日龄取胸肌评价肉品质。【结果】与对照组相比,复合酶组、枯草芽孢杆菌组和联用组黄羽肉鸡的生长性能均无显著差异(P>0.05),但均可显著提高21日龄黄羽肉鸡的肝脏指数(P<0.05),并可显著降低63日龄黄羽肉鸡肌肉滴水损失(P<0.05);复合酶或枯草芽孢杆菌单独添加均可显著降低21日龄黄羽肉鸡盲肠微生物菌群中肠球菌属菌群数量(P<0.05),并可显著降低63日龄黄羽肉鸡血浆尿素氮(BUN)水平(P<0.05),显著提高肝脏总超氧化物歧化酶(T-SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性(P<0.05);复合酶单独添加可显著降低21日龄黄羽肉鸡血浆BUN水平(P<0.05);枯草芽孢杆菌单独添加可显著提高21日龄黄羽肉鸡肝脏胆碱酯酶(CHE)活性(P<0.05)。与抗生素组相比,复合酶与枯草芽孢杆菌联合添加对63日龄黄羽肉鸡肝脏指数无显著影响(P>0.05),但显著增加了黄羽肉鸡24 h肉色黄度值(P<0.05)。与联用组相比,复合酶或枯草芽孢杆菌单独添加均可显著提高63日龄黄羽肉鸡肝脏中GSH-Px和琥珀酸脱氢酶(SHD)活性(P<0.05),但对黄羽肉鸡盲肠微生物菌群组成均无显著影响(P>0.05)。【结论】饲粮单独添加复合酶或枯草芽孢杆菌均可增强黄羽肉鸡肝脏抗氧化能力和代谢功能,降低盲肠有害菌数量,改善黄羽肉鸡肉品质,但两者联合添加时并没有表现出协同作用。

【Objective】This experiment was conducted to investigate the effects of complex enzymes and Bacillus subtilis on growth performance,meat quality and liver function of Yellow-feathered broilers.【Method】A total of 12001-day-old fast large Yellow-feathered cocks were randomly divided into 5 groups with 6 replicates per group and 40 chickens per replicate.The birds in control group were fed basal diet,and the birds in other four groups were fed the basal diet supplemented with 20 mg/kg virginiamycin(antibiotic group),500 mg/kg complex enzymes(complex enzymes group),200 mg/kg Bacillus subtilis(Bacillus subtilis group)and 500 mg/kg complex enzymes+200 mg/kg Bacillus subtilis(combined group),respectively.The experiment lasted for 63 days.At 21,42 and 63 days of age,broilers were weighed with fasting and feed intake was calculated to calculate growth performance.Two chickens from each replicate at 21 and 63 days of age were slaughtered.Blood and liver tissue samples were collected and biochemical parameters were determined.At 21 days of age,cecum contents were collected to determine the number of microflora.Breast muscle was taken at 63 days of age to evaluate meat quality.【Result】Compared with the control group,there were no significant differences in the growth performance of Yellow-feathered broilers in complex enzymes group,Bacillus subtilis group and the combined group(P>0.05),but the liver index at 21 days was significantly increased(P<0.05),and the muscle dripping loss at 63 days of age was significantly decreased(P<0.05)in three groups.Compared with the control group,the supplementation of complex enzymes or Bacillus subtilis alone significantly decreased Enterococcus microflora in cecum of Yellow-feathered broilers at 21 days of age(P<0.05),significantly decreased plasma urea nitrogen(BUN)level at 63 days of age(P<0.05),and significantly increased the activities of T-superoxide dismutase(T-SOD)and glutathione peroxidase(GSH-Px)in liver(P<0.05).Compared with the control group,the plasma BUN level of Yellow-feathered broilers at 21 days of age was significantly decreased by complex enzymes supplementation alone(P<0.05).And the supplementation of Bacillus subtilis alone significantly increased the activity of choline esterase(CHE)in liver of 21-day-old Yellow-feathered broilers(P<0.05).Compared with antibiotic group,the combined supplementation of complex enzymes and Bacillus subtilis had no significant effect on liver index of 63-day-old Yellow-feathered broilers(P>0.05),but significantly increased the meat yellowness value at 24 h(P<0.05).Compared with the combined group,the supplementation of complex enzymes or Bacillus subtilis alone significantly increased GSH-Px and succinate dehydrogenase(SDH)activities in the liver of 63-day-old Yellow-feathered broilers(P<0.05),but had no significant effect on the composition of cecal microbiota(P>0.05).【Conclusion】Dietary supplementation of complex enzymes or Bacillus subtilis alone could enhance the antioxidant capacity and metabolic function of liver,improve meat quality and reduce the number of harmful bacteria in cecum of Yellow-feathered broilers.However,there was no synergistic effect of the supplementation of complex enzymes and Bacillus subtilis.