饲料中豆粕替代鱼粉对大黄鱼生长、消化酶活性和消化道组织学的影响

以初始体重为(10.57g±0.43g)的大黄鱼幼鱼为研究对象,用豆粕分别替代0%、35%、40%、45%的鱼粉来配制4种等氮(蛋白含量为46%)等脂(总脂肪为13%)的实验饲料,分别编号为FM,PP35,PP40和PP45。其中,在PP35、PP40和PP45组均添加肽聚糖、胆固醇、植酸酶、晶体氨基酸和复合益生菌,并以FM组和鲜鱼浆(FTF)组作为对照,在海水浮式网箱中进行为期60d的摄食生长实验,探讨不同豆粕替代水平对大黄鱼幼鱼生长、消化酶活性和消化道组织学的影响。结果表明,豆粕替代水平对大黄鱼幼鱼的生长和存活没有显著影响(P>0.05)。肠道胰蛋白酶的活性随着豆粕替代水平的升高而显著降低(P<0.05),FM组的胰蛋白酶活性最高,而FTF组的最低。肠道脂肪酶活性随着豆粕替代水平的升高呈现先升高后降低的趋势,FTF组脂肪酶活性最低。肠道淀粉酶活性随着豆粕替代水平的增高同样呈现降低趋势,但无显著差异(P>0.05)。高豆粕替代水平(PP40和PP45组)对肝脏组织和肠道组织结构有破坏作用,PP45组实验鱼肝脏空泡化现象严重,肠壁明显变薄,小肠绒毛受到严重机械性损伤。实验证明,在大黄鱼幼鱼饲料中可以使用豆粕来替代35%的鱼粉既不影响大黄鱼的生长和存活,也不影响其肠道、肝脏的组织结构。

Effects of Replacement of Dietary Fish Meal by Soybean Meal on Growth, Digestive Enzyme Activity and Digestive Tract Histology of Juvenile Large Yellow Croaker,Pseudosciaena crocea R.

A 60 d feeding trial was conducted in floating net cage to investigate the effects of replacement of dietary fish meal by soybean meal on growth performance,digestive enzyme activity and digestive tract histology of juvenile large yellow croaker,Pseudosciaena crocea R(initial weight 10.57±0.43g).Four isonitrogenous(crude protein 46%) and isolipidic(crude lipid 13%) practical diets were formulated by replacing 0%,35%,40%,45% fishmeal with soybean meal(SBM).The four artificial diets were named as FM,PP35,PP40 and PP45,respectively.Phytase,crystal amino acids and composite bacteria were added to the treatment of PP35,PP40 and PP45.Fresh trash fish(FTF) diet and the FM diet were used as control.Results showed that there were no significant differences in the special growth rate(SGR) and survival among all the treatments.With the increasing dietary soybean meal level,trypsin activity in intestine significantly decreased,and lipase activity increased and then decreased.The amylase activity decreased but not significant.The histological study showed that ultrastructure of the liver and the intestine in PP40 and PP45 treatments were abnormal.Serious vacuolization in liver,significant thinning of the intestinal wall and the severe mechanical damage of intestinal villi were found in PP45 treatment.In conclusion,replacement of fish meal by SBM at the level of 35% can be considered as an optimum replacement level under the present experimental condition.