发酵棉籽粉替代鱼粉对卵形鲳鲹幼鱼生长、饲料利用性能及肠道菌群的影响

Effects of replacement of fish meal by fermented cottonseed meal ongrowth performance,feed utilization and intestinal bacteria community ofjuvenile golden pompano(Trachinotus ovatus)

发酵棉籽粉是一种优质植物蛋白原料,具有替代饲料鱼粉的潜力。为评估发酵棉籽粉作为卵形鲳鲹(Trachinotus ovatus)饲料蛋白源的适宜性及适宜替代水平,用发酵棉籽粉分别替代卵形鲳鲹幼鱼饲料中0%(对照组)、25%、50%、75%和100%的鱼粉(基础饲料中鱼粉质量分数为35%),配制成5种实验饲料,饲喂幼鱼[初始体质量为(12.57±0.25)g]7周,探究了发酵棉籽粉替代鱼粉对幼鱼存活、生长和饲料利用性能及肠道菌群组成的影响。结果显示,发酵棉籽粉替代组的存活、生长、饲料利用率以及蛋白质、脂肪沉积效率均低于鱼粉对照组,而25%和50%替代组与对照组无显著性差异(P>0.05)。但当发酵棉籽粉替代75%~100%鱼粉时,刺激了卵形鲳鲹肝脏的抗氧化系统,使总超氧化物歧化酶(T-SOD)和过氧化氢酶(CAT)活性高于对照组。此外肝脏HE染色切片显示其细胞空泡化现象加剧,100%替代组的血清总蛋白、白蛋白和球蛋白含量降低,肝脏合成蛋白能力可能下降。发酵棉籽粉高水平替代鱼粉会影响卵形鲳鲹的肠道菌群组成,表现为有益菌丰度下降、有害菌丰度上升,从而影响了肠道菌群功能。综合考虑生长性能和鱼体健康,建议卵形鲳鲹饲料中发酵棉籽粉替代鱼粉水平以25%为宜。

Fermented cottonseed meal(FCSM)is a high-quality plant protein ingredient with potential to replace fishmeal in feed.To evaluate the suitability of FCSM as a protein source in the diet of juvenile golden pompano(Trachinotus ovatus)and its appropriate replacement level,we had fed the juveniles with initial body mass of(12.57±0.25)g for seven weeks by five diets to replace 0%(Control group),25%,50%and 100%of fishmeal by FCSM,and the fish meal in reference diet was 35%.Then we investigated the effects of FCSM replacement of fishmeal on the survival,growth,feed utilization performance and intestinal mi-croflora of the juveniles.The results show that the survival,growth,feed efficiency,dietary protein and lipid deposition rates were lower in FCSM treatments compared with those in reference diet,while the differences between 25%,50%replacement groups and the reference diet were not significant(P>0.05).However,the liver antioxidant system was stimulated,and the activi-ties of total superoxide dismutase(T-SOD)and catalase(CAT)in 75%−100%replacement groups were higher than those in the control group.In addition,the liver hematoxylin-eosin-stained sections show that the cellular vacuolation phenomenon was ag-gravated.The contents of total protein,albumin and globulin in serum in 100%replacement group were reduced,and the pro-tein synthesis capacity of liver might be impaired.High-level replacement of fish meal by FCSM affected the composition of in-testinal flora,with the abundance of beneficial bacteria decreasing and that of harmful bacteria increasing.Taking into account both growth performance and fish health,it is recommended to replace fish meal with 25%FCSM in the diet for T.ovatus.