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以棉粕蛋白为酶解底物,用枯草杆菌蛋白酶对其进行酶解,以酶解产物1.5%和3.0%两个梯度等量替代鱼饲料配方中棉粕,在室内流水养殖系统中喂养异育银鲫鱼种[体重为(30±2)g]65天。测定鱼的生长、营养物质表观消化率、消化蛋白酶活性及肝胰脏中胰蛋白酶mRNA表达水平等指标。结果表明,添加1.5%和3.0%棉粕酶解产物的鱼在饲养35天后的特定增长率(SGR)分别比对照组高32.5%和56.7%,且差异显著(P<0.05);在饲养65天后,两组特定增长率分别比对照组高8.0%和21.0%,且差异极显著(P<0.01),肝胰脏中胰蛋白酶mRNA表达水平也随棉粕酶解产物添加梯度提高而相应提高,表明鱼的生长与消化蛋白酶mRNA表达水平相关。同时棉粕蛋白酶解物对肠道蛋白酶的活性和营养物质表观消化率都有促进作用,而棉粕蛋白酶解物对鱼肌肉成分并没有改变,这也表明棉粕蛋白酶解物在促进鱼生长、内源酶活性同时并未降低鱼的品质。
Using cottonseed meal as substrate for enzymatic hydrolysis, subtilisin was used to digest cottonseed meal with the same gradient of 1.5% and 3.0%, respectively, to feed cottonseed meal in fish feed formula, Silver carp species [weighing (30 ± 2) g] 65 days. Fish growth, apparent digestibility of nutrients, digestive protease activity and trypsin mRNA expression levels in hepatopancreas and other indicators were determined. The results showed that the specific growth rate (SGR) of fish with 1.5% and 3.0% cottonseed meal hydrolyzate after 35 days of feeding was 32.5% and 56.7% higher than that of the control group respectively (P <0.05) The specific growth rates of the two groups were 8.0% and 21.0% higher than those of the control group respectively (P <0.01), and the levels of trypsin mRNA in hepatopancreas increased with the increase of the enzymatic hydrolysis products , Indicating that the fish growth and digestive protease mRNA expression level. At the same time, cottonseed meal hydrolyzate had an effect on the activity of protease and the apparent digestibility of nutrients, while the cottonseed meal hydrolyzate did not change the muscle composition of fish, which also indicated that cottonseed meal hydrolyzate promoted fish growth , Endogenous enzyme activity did not reduce the quality of fish at the same time.