中性植酸酶对异育银鲫鱼种生长的影响及其在肠道中酶活分布状况

Effect of neutral phytase on growth of allogynogentic crucian fingerlings and its activity distribution in intestinal canals

探讨中性植酸酶对异育银鲫鱼种生产性能、消化道指数的影响及其酶活在肠道中分布状况。对照组饲喂基础日粮,Ⅱ、Ⅲ和Ⅳ组在基础日粮中分别添加500、1 000和1 500 U/kg的中性植酸酶,饲喂60 d。结果表明:Ⅱ、Ⅲ和Ⅳ组平均增重率比对照组分别提高1.69、8.76和1.64个百分点,饵料系数分别降低4.21%、6.90%和2.30%;其中Ⅲ组平均增重率最高,饵料系数最低。Ⅱ、Ⅲ和Ⅳ组肝体比显著高于对照组,Ⅲ组最大,比对照组提高11.26%。中性植酸酶酶活性大小在肠道中的分布依次为:中肠、前肠、后肠;与对照组相比,Ⅱ、Ⅲ和Ⅳ组各段肠道中性植酸酶活性都增加显著。配合饲料中添加1 000 U/kg中性植酸酶能在异育银鲫肠道中较好地发挥酶活作用。

The effect of neutral Phytase on production performance, digestive canal indexes of allogynogentic crucian fingerlings and its Activity Distribution in Intestinal Canals was studied. The Control Group was fed on basal diets, and Group Ⅱ , Ⅲ and Ⅳ were fed on basal diets with addition of 500, 1 000 and 1 500 U/kg neutral phytase for 60 d respectively. The results showed that the average weight gain of Group Ⅱ ,Ⅲ and Ⅳ was increased by 1.69%, 8.76% and 1.64% respectively in comparison with Control Group, and the feed coefficient was reduced by 0.11%, 0.18%and 0. 06% respectively, of which the average weight gain of Group m was the highest and the feed coefficient was the lowest. The liver--body ratio of Group Ⅱ ,Ⅲ and Ⅳ was significantly higher than that of Control Group, and the liver--body ratio of Group m was maximal and increased by 11. 26% in comparison with Control Group. The activity of neutral phytase was distributed in intestinal canals successively： midgut, foregut and hindgut; in comparison with Control Group, The activity of neutral phytase in all intestinal canals of Group Ⅱ , Ⅲ and Ⅳ was increased significantly. Adding 1 000 U/kg neutral phytase into the formula feeds could exert the enzyme activity well in the intestinal canals of allogynogentic crueian.