低蛋白质饲料对湘云鲫幼鱼生长性能及肠道、肝脏健康的影响

Effects of Low Protein Diets on Growth Performance and Intestinal and Liver Health of Juvenile Triploid Crucian Carp

本试验旨在研究低蛋白质饲料对湘云鲫幼鱼生长性能及肠道、肝脏健康的影响。选择初始体重为(37.15±0.46)g、体质健壮的湘云鲫幼鱼360尾,随机分为6组,每组3个重复,每个重复20尾。各组分别饲喂蛋白质水平分别为37%、36%、35%、34%、33%、32%的6种等能饲料。试验期8周。结果表明:1)32%、33%和34%蛋白质水平组的终末均重和特定生长率显著低于37%蛋白质水平组(P<0.05),32%、33%、34%和35%蛋白质水平组的增重率显著低于37%蛋白质水平组(P<0.05),32%、33%、34%和35%蛋白质水平组的饲料系数显著高于37%蛋白质水平组(P<0.05)。33%蛋白质水平组的脏体比显著低于37%蛋白质水平组(P<0.05)。32%、33%、34%、35%和36%蛋白质水平组的全鱼粗蛋白质含量显著低于37%蛋白质水平组(P<0.05),32%、33%、34%和35%蛋白质水平组的内脏团和肌肉粗脂肪含量显著高于37%蛋白质水平组(P<0.05)。2)32%、33%和35%蛋白质水平组的肠道胰蛋白酶活性显著低于37%蛋白质水平组(P<0.05)。32%蛋白水平组的肠道绒毛高度显著低于37%蛋白质水平组(P<0.05)。32%和33%蛋白质水平组的血浆二胺氧化酶活性显著高于37%蛋白质水平组(P<0.05)。3)32%、33%和34%蛋白质水平组的血浆甘油三酯含量显著高于37%蛋白质水平组(P<0.05)。32%、33%、34%和35%蛋白质水平组的肝脏总抗氧化能力显著低于37%蛋白质水平组(P<0.05),32%蛋白质水平组的肝脏丙二醛含量显著高于37%蛋白质水平组(P<0.05)。综上所述,适当降低饲料蛋白质水平(36%)的可在不影响生长性能和肝脏健康的前提下,提高肠道代谢和屏障功能,但饲料蛋白质水平过低(≤35%)会引起生长性能下降,肠道和肝脏健康受损。在本试验条件下,综合考虑生长性能与健康状况,饲料蛋白质水平为36%时,不影响湘云鲫幼鱼生长性能和肝脏健康,且有助于激活肠道功能,在实现蛋白质节约的同时保障湘云鲫幼鱼的健康生长。

This experiment was conducted to study the effects of low protein diets on growth performance and intestinal and liver health of juvenile triploid crucian carp.A total of 360 healthy juvenile triploid crucian carp with the initial weight of(37.15±0.46)g were randomly divided into 6 groups with 3 replicates per group and 20 fish per replicate.Fish in 6 groups were fed six isoenergetic diets with protein levels of 37%,36%,35%,34%,33%and 32%,respectively.The experiment lasted for 8 weeks.The results showed as follows:1)the final average weight and specific growth rate of 32%,33%and 34%protein level groups were significantly lower than those of 37%protein level group(P<0.05),the weight gain rate of 32%,33%,34%and 35%protein level groups was significantly lower than that of 37%protein level group(P<0.05),and the feed coef⁃ficient of 32%,33%,34%and 35%protein level groups was significantly higher than that of 37%protein lev⁃el group(P<0.05).The viscerosomatic index of 33%protein level group was significantly lower than that of 37%protein level group(P<0.05).The whole fish crude protein content of 32%,33%,34%,35%and 36%protein level groups was significantly lower than that of 37%protein level group(P<0.05),and the visceral mass and muscle ether extract content of 32%,33%,34%,35%and 36%protein level groups was signifi⁃cantly higher than that of 37%protein level group(P<0.05).2)The intestinal trypsin activity of 32%,33%and 35%protein level groups was significantly lower than that of 37%protein level group(P<0.05).The in⁃testinal villi height of 32%protein level group was significantly lower than that of 37%protein level group(P<0.05).The plasm diamine oxidase activity of 32%and 33%protein level groups was significantly higher than that of 37%protein level group(P<0.05).3)The plasm triglyceride content of 32%,33%and 34%protein level groups was significantly higher than that of 37%protein level group(P<0.05).The liver total antioxidant capacity of 32%,33%,34%and 35%protein level groups was significantly lower than that of 37%protein level group(P<0.05),and the liver malondialdehyde content of 32%protein level group was significantly higher than that of 37%protein level group(P<0.05).In conclusion,appropriate reduction of dietary protein level(36%)can improve the intestinal metabolism and barrier function without affecting growth performance and liver health,but excessive dietary protein level diet(≤35%)causes growth performance decreased and intestinal and liver health damaged.Under the conditions of this experiment,comprehensive considering the growth performance and health status,when the dietary protein level is 36%,it has no effects on the growth performance and liver health of juvenile triploid crucian carp,and helps activate intestinal functions,and achie⁃ving protein savings and ensuring the healthy growth of juvenile triploid crucian carp.