Yuan Lin, Wang Mingfa, Zhang Xiaotu, Wang Zhixiang
College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
Institute of Animal Husbandry and Veterinary Medicine, Henan Academy of Agricultural Sciences, Zhengzhou, China.
PLoS One. 2017 Mar 21;12(3):e0173941. doi: 10.1371/journal.pone.0173941. eCollection 2017.
Three hundred one-day-old male broiler chickens (Ross-308) were fed corn-soybean basal diets containing non-starch polysaccharide (NSP) enzyme and different levels of acid protease from 1 to 42 days of age to investigate the effects of exogenous enzymes on growth performance, digestive function, activity of endogenous digestive enzymes in the pancreas and mRNA expression of pancreatic digestive enzymes. For days 1-42, compared to the control chickens, average daily feed intake (ADFI) and average daily gain (ADG) were significantly enhanced by the addition of NSP enzyme in combination with protease supplementation at 40 or 80 mg/kg (p<0.05). Feed-to-gain ratio (FGR) was significantly improved by supplementation with NSP enzymes or NSP enzyme combined with 40 or 80 mg/kg protease compared to the control diet (p<0.05). Apparent digestibility of crude protein (ADCP) was significantly enhanced by the addition of NSP enzyme or NSP enzyme combined with 40 or 80 mg/kg protease (p<0.05). Cholecystokinin (CCK) level in serum was reduced by 31.39% with NSP enzyme combined with protease supplementation at 160 mg/kg (p<0.05), but the CCK level in serum was increased by 26.51% with NSP enzyme supplementation alone. After 21 days, supplementation with NSP enzyme and NSP enzyme combined with 40 or 80 mg/kg protease increased the activity of pancreatic trypsin by 74.13%, 70.66% and 42.59% (p<0.05), respectively. After 42 days, supplementation with NSP enzyme and NSP enzyme combined with 40 mg/kg protease increased the activity of pancreatic trypsin by 32.45% and 27.41%, respectively (p<0.05). However, supplementation with NSP enzyme and 80 or 160 mg/kg protease decreased the activity of pancreatic trypsin by 10.75% and 25.88%, respectively (p<0.05). The activities of pancreatic lipase and amylase were significantly higher in treated animals than they were in the control group (p<0.05). Supplementation with NSP enzyme, NSP enzyme combined with 40 or 80 mg/kg protease increased pancreatic trypsin mRNA levels by 40%, 44% and 28%, respectively. Supplementation with NSP enzyme and 160 mg/kg protease decreased pancreatic trypsin mRNA levels by 13%. Pancreatic lipase and amylase mRNA expression were significantly elevated in treated animals compared to the control group (p<0.05). These results suggest that the amount of NSP enzyme and acid protease in the diet significantly affects digestive function, endogenous digestive-enzyme activity and mRNA expression in broilers.
选用300只1日龄雄性罗斯308肉鸡,在1至42日龄期间饲喂含有非淀粉多糖(NSP)酶和不同水平酸性蛋白酶的玉米 - 大豆基础日粮,以研究外源酶对生长性能、消化功能、胰腺内源性消化酶活性及胰腺消化酶mRNA表达的影响。在1至42日龄期间,与对照鸡相比,添加NSP酶并补充40或80mg/kg蛋白酶可显著提高平均日采食量(ADFI)和平均日增重(ADG)(p<0.05)。与对照日粮相比,补充NSP酶或NSP酶与40或80mg/kg蛋白酶组合可显著改善料重比(FGR)(p<0.05)。添加NSP酶或NSP酶与40或80mg/kg蛋白酶组合可显著提高粗蛋白表观消化率(ADCP)(p<0.05)。160mg/kg NSP酶与蛋白酶组合补充可使血清胆囊收缩素(CCK)水平降低31.39%(p<0.05),但单独补充NSP酶可使血清CCK水平升高26.51%。21天后,补充NSP酶以及NSP酶与40或80mg/kg蛋白酶组合分别使胰腺胰蛋白酶活性提高74.13%、70.66%和42.59%(p<0.05)。42天后,补充NSP酶以及NSP酶与40mg/kg蛋白酶组合分别使胰腺胰蛋白酶活性提高32.45%和27.41%(p<0.05)。然而,补充NSP酶与80或160mg/kg蛋白酶分别使胰腺胰蛋白酶活性降低10.75%和25.88%(p<0.05)。处理组动物的胰腺脂肪酶和淀粉酶活性显著高于对照组(p<0.05)。补充NSP酶、NSP酶与40或80mg/kg蛋白酶组合分别使胰腺胰蛋白酶mRNA水平提高40%、44%和28%。补充NSP酶与160mg/kg蛋白酶使胰腺胰蛋白酶mRNA水平降低13%。与对照组相比,处理组动物胰腺脂肪酶和淀粉酶mRNA表达显著升高(p<0.05)。这些结果表明,日粮中NSP酶和酸性蛋白酶的含量显著影响肉鸡的消化功能、内源性消化酶活性及mRNA表达。