低磷低鱼粉饲料中添加植酸酶和蛋白酶对草鱼生长性能和消化生理的影响

本试验旨在研究低磷低鱼粉饲料中添加植酸酶和蛋白酶对草鱼生长性能、消化酶活性、营养物质表观消化率和免疫力的影响。试验选取平均体重为9.66 g的健康草鱼630尾,随机分为7个组,每组3个重复,每个重复30尾鱼。7组草鱼饲喂如下试验饲料:正常磷(磷酸二氢钙添加量2.0%)正常鱼粉(鱼粉添加量3.0%)饲料(对照)、低磷(磷酸二氢钙添加量1.3%)正常鱼粉饲料、低磷正常鱼粉并添加0.03%植酸酶饲料、正常磷低鱼粉(鱼粉添加量1.5%)饲料、正常磷低鱼粉并添加0.05%蛋白酶饲料、低磷和低鱼粉饲料、低磷低鱼粉并添加0.03%植酸酶和0.05%蛋白酶饲料。饲养试验持续56 d。结果显示:与饲喂正常磷正常鱼粉饲料草鱼相比,饲喂低磷低鱼粉饲料草鱼的增重率、特定生长率、营养物质(干物质、蛋白质、钙和磷)表观消化率、肠道消化酶(胰蛋白酶、糜蛋白酶和淀粉酶)活性、血清溶菌酶活性均显著降低(P<0.05),饲料系数和血清丙二醛含量显著升高(P<0.05)。在低磷正常鱼粉饲料、正常磷低鱼粉饲料、低磷低鱼粉饲料中分别添加植酸酶、蛋白酶、植酸酶与蛋白酶后,草鱼的上述指标均得到显著改善(P<0.05)。以上结果表明,在低磷低鱼粉饲料中添加植酸酶和蛋白酶能够提高草鱼的营养物质表观消化率、肠道消化酶活性和免疫力,从而改善其生长性能。

Effects of Adding Phytase and Protease in Low Phosphorus and Low Fish Meal Diets on Growth Performance and Digestive Physiology of Grass Carp(Ctenopharyngodon idella)

This experiment was conducted to investigate the effects of adding phytase and protease in low phosphorus(P)and low fish meal(FM)diets on the growth performance,digestive enzyme activities,nutrient apparent digestibility coefficients and immunity of grass carp(Ctenopharyngodon idella).A total of 630 healthy grass carp with an initial body weight about 9.66 g were randomly divided into 7 groups with 3 replicates per group and 30 fish per replicate.Fish in 7 groups were fed the following diets for 56 days:normal P2.0%Ca(H2PO4)2]and normal FM(3.0%fish meal)diet(control),low P1.3%Ca(H2PO4)2]and normal FM diet,low P and normal FM+0.03%phytase diet,normal P and low FM(1.5%FM)diet,normal P and low FM+0.05%protease diet,low P and low FM diet,low P and low FM+0.03%phytase+0.05%protease diet.The results showed that compared with the fish fed normal P and normal FM diet,the weight gain rate,specific growth rate,the apparent digestibility coefficients of nutrientscrude protein(CP),calcium(Ca)and P],the activities of digestive enzyme(trypsin,chymotrypsin and amylase)and the activity of serum lysozyme of fish fed low P and low FM diet were significantly decreased(P<0.05),while the feed conversion rate and serum malondialdehyde content were significantly increased(P<0.05).Adding phytase,protease,phytase and protease in the low P and normal FM diet,normal P and low FM and low P and low FM diet,respectively,the above indices of fish were significantly improved(P<0.05).It is concluded that adding phytase and protease in the low P and low FM diet can enhance the nutrient apparent digestibility coefficients,intestinal digestive enzyme actives and immunity,and then improve the growth performance of grass carp.