家蝇蛆粉替代鱼粉对凡纳滨对虾消化酶、转氨酶活性和肝胰腺组织结构的影响

试验采用28%鱼粉饲料为基础，以家蝇蛆粉分别替代20%、40%、60%、80%和100%的鱼粉配制5种试验饲料，投喂初始体质量为0.56 g的凡纳滨对虾（Litopenaeus vannamei）45 d，研究了蝇蛆粉对凡纳滨对虾消化酶、转氨酶活性和肝胰腺结构的影响。结果显示，替代组对虾肝胰腺、胃和肠道消化酶活性与对照组相比差异不显著（P＞0.05）。替代组对虾肝胰腺谷丙转氨酶（ALT）、谷草转氨酶（AST）活性均低于对照组，但差异不显著（P＞0.05）；随着替代水平的增加，血清ALT活性在100%替代组、AST活性在60%-100%替代组显著降低（P＜0.05）。与对照组相比，20%-60%替代组肝胰腺上皮细胞中空泡增多，并且出现未知物质；替代水平高于60%时肝胰腺结构损伤严重。结果表明，蝇蛆粉替代水平在60%以下时，对凡纳滨对虾消化酶和转氨酶活性没有显著影响，对肝胰腺结构损伤不明显。

Effects of replacement of fish meal with housefly maggot meal on digestive enzymes, transaminases activities and hepatopancreas histological structure of Litopenaeus vannamei

To investigate the effects of housefly maggot meal （HMM） on the digestive enzymes, transaminases activities and hepatopancreas histological structure of Litopenaeus vannamei, we formulated 5 diets with 20%, 40%, 60%, 80% and 100% replacement of fish meal with HMM in basal diet, and fed them to L.vannamei （initial weight 0.56 g） for 45 d. Results show that no significant difference was found in digestive enzymes activities in hepatopancreas, stomach and intestine of L.vannamei in HMM groups compared to the control （P〉0.05）. The alanine aminotransferase （ALT） and aspartate aminotransferase （AST） activities in hepatopancreas in HMM groups were lower than those in the control with no significant difference （P〉0.05）, while serum ALT activity in 100% group and AST activities in 60%~100% groups decreased significantly （P〈0.05）. Compared to the control, numbers of vacuoles increased and unknown substances appeared in the epithelial cells in 20%~60% groups; hepatopancreas histological structures were seriously injured in 80% and 100% groups. In conclusion, when the substitution level is lower than 60%, HMM has neither significant effects on digestive enzymes and transaminases activities of L.vannamei nor serious injury to hepatopancreas histological structure.