本试验旨在研究饲料中玉米淀粉添加水平对鲤生长性能、消化酶活性及血清生化指标的影响。选用平均体重为(36.12±1.18) g的鲤900尾,随机分成5组,每组3个重复,每个重复60尾鱼,分别投喂蛋白质水平依次为32.0%、30.0%、28.1%、26.2%、24.2%,玉米淀粉添加水平依次为0(对照)、6.5%、13.0%、19.5%、26.0%的试验饲料,饲养时间为9周。结果表明:从生长性能看,对照组的增重率、特定生长率显著高于其他各组(P<0.05);26.0%玉米淀粉组的饲料系数、蛋白质效率显著高于对照组(P<0.05)。饲料中玉米淀粉添加水平对鲤肝胰脏脂肪酶活性的影响不显著(P>0.05);前肠中,13.0%玉米淀粉组脂肪酶活性显著高于6.5%玉米淀粉组(P<0.05);中肠中,对照组、19.5%玉米淀粉组脂肪酶活性显著高于6.5%玉米淀粉组(P<0.05);后肠中,26.0%玉米淀粉组脂肪酶活性显著高于19.5%玉米淀粉组(P<0.05)。肝胰脏中,26.0%玉米淀粉组淀粉酶活性显著高于其他各组(P<0.05);前肠、中肠和后肠中,6.5%玉米淀粉组淀粉酶活性显著高于其他各组(P<0.05)。肝胰脏、前肠、中肠、后肠中蛋白酶活性均随饲料中玉米淀粉添加水平的升高而显著降低(P<0.05)。血清葡萄糖含量随饲料中玉米淀粉添加水平的升高而呈上升趋势,且各组间差异显著(P<0.05)。血清胆固醇含量以26.0%玉米淀粉组最高,显著高于其他各组(P<0.05),以6.5%玉米淀粉组最低,显著低于其他各组(P<0.05)。血清甘油三酯含量以26.0%玉米淀粉组最高,显著高于其他各组(P<0.05),以6.5%、13.0%玉米淀粉组较低,显著低于其他各组(P<0.05)。综合分析,在本试验条件下,适当降低饲料蛋白质水平可提高鲤的消化能力,饲料中玉米淀粉添加水平在0~13.0%、蛋白质水平在28.1%~32.0%时较适合鲤的生长。

This experiment was conducted to investigate the effects of dietary corn starch supplemental level on growth performance, digestive enzyme activities and serum biochemical indices of common carp. Nine hundred common carp with the average body weight of(36.12±1.18) g were randomly divided into 5 groups with 3 replicates in each group and 60 fish in each replicate. The fish in those groups were fed with five experimental diets. In the five experimental diets, the protein level was in order of 32.0%, 30.0%, 28.1%, 26.2% and 24.2%, and the corn starch supplemental level was in order of 0(control), 6.5%, 13.0%, 19.5% and 26.0%. The experiment lasted for 9 weeks. The results showed as follows:seeing from growth performance, weight gain rate and specific growth rate in control group were significantly higher than those in other groups(P<0.05). Feed conversion ratio and protein efficient ratio in 26.0% corn starch group were significantly higher than those in control group(P<0.05). Dietary corn starch supplemental level had no significant effect on lipase activity in hepatopancreas(P>0.05). Foregut lipase activity in 13.0% corn starch group was significantly higher than that in 6.5% corn starch group(P<0.05). Midgut lipase activity in control group and 19.5% corn starch group was significantly higher than that in 6.5% corn starch group(P<0.05). Hindgut lipase activity in 26.0% corn starch group was significantly higher than that in 19.5% corn starch group(P<0.05). Hepatopancreas amylase activity in 26.0% corn starch group was significantly higher than that in other groups(P<0.05). In foregut, midgut and hindgut, the amylase activity in 6.5% corn starch group was significantly higher than that in other groups(P<0.05). The protease activity in hepatopancreas, foregut, midgut and hindgut was significantly decreased with the increase of dietary corn starch supplemental level(P<0.05). Serum glucose content showed an increasing trend with the increase of dietary corn starch supplemental level, and the difference was significant among all groups(P<0.05). Serum cholesterol content in 26.0% corn starch group was the highest, which was significantly higher than that in other groups(P<0.05); and it in 6.5% corn starch group was the lowest, which was significantly lower than that in other groups(P<0.05). Serum triglyceride content in 26.0% corn starch group was the highest, which was significantly higher than that in other groups(P<0.05); and it in 6.5% and 13.0% corn starch groups was lower, which was significantly lower than that in other groups(P<0.05). Comprehensive analysis of the measured indices, the digestive capacity of common carp can be raised by properly reducing protein level, and when dietary corn starch supplemental level at 0 to 13.0% and protein level at 28.1% to 32.0% are suitable for growth of common carp in this experimental condition.