不同含量水解鱼蛋白添加对大菱鲆幼鱼生长、血浆和肌肉游离氨基酸含量及后肠组织形态的影响

为研究水解鱼蛋白(FPH)对大菱鲆(Scophthalmus maximus L.)幼鱼生长的影响,本实验以60%的鱼粉(FM)组为正对照组,以复合植物蛋白源替代40%的FM作为负对照组(含36%的FM),在负对照组的基础上添加3个梯度水平(3%、6%、9%)的FPH作为实验组,分别喂养大菱鲆幼鱼74 d。研究表明,与负对照组相比,添加6%和9%的FPH可显著提高大菱鲆幼鱼的生长性能,并达到与正对照组相似的效果。添加不同含量的FPH会改善大菱鲆幼鱼的后肠形态,且改善状况随添加量的增加而愈加明显,当FPH添加水平达到9%时,可显著增加大菱鲆幼鱼后肠的肠绒毛直径比、肠上皮细胞高度和微绒毛高度。与负对照组相比,9%FPH组显著提高了血浆和肌肉中必需氨基酸、非必需氨基酸和总氨基酸浓度。此外,饲料中添加6%和9%的FPH显著促进了PepT1的基因表达量。研究结果表明,水解鱼蛋白是一种潜在的替代鱼粉的有效蛋白源,可起到改善大菱鲆幼鱼生长指标、提高机体游离氨基酸含量和促进肠道吸收能力的作用。

Dietary Fish Protein Hydrolysate Modulates Growth Performance and Free Amino Acid Profile in Plasma and Muscle and Posterior Intestinal Morphology of Juvenile Turbot

To study the influence of fish protein hydrolysate(FPH)on the growth of juvenile turbot,3%,6%and 9%of FPH was added to the diet containing relatively low fishmeal(36%fishmeal,negative control).A fish meal based diet(60%fishmeal)was set as the positive control.In a 74-day feeding trial,the potential effect of FPH on the nutritional physiology of juvenile turbot was determined.Supp-lying 6%and 9%of FPH significantly improved the growth performance of turbot and achieved a parallel performance with that of positive control.Compared with the negative control,9%of FPH significantly enhanced the essential amino acid(EAA),non-essential amino acid(NEAA)and AA concentrations in plasma while 9%of FPH obviously increased EAA and AA concentrations of muscle.The height of intestinal villus,enterocyte and microvillus was also enhanced by 6%and 9%of FPH in comparison with that of negative control.Moreover,supplying 6%and 9%of FPH to the diet significantly induced the mRNA abundance of peptide transporter 1 gene(PepT1)in distal intestine.Our results showed that FPH is an effective ingredient,which elevates the nutritive value of diets and reduces the fishmeal level in carnivorous fishes.