组胺对黄颡鱼生长及体色变异的影响

试验在基础饲料中分别添加0、10、100、1 000 mg/kg的组胺,制成4种等氮饲料(分别记为C、H10、H100和H1000),以黄颡鱼(Pelteobagrus fulvidraco)(102.13±0.52)g为试验对象,进行56 d的养殖试验,研究不同添加水平组胺对黄颡鱼生长、皮肤显微结构、皮肤黑色素含量、酪氨酸酶活力和脑中黑素皮质素受体-1(MC1R)mRNA表达量的影响。试验采用微流水室内养殖系统,结果表明:饲料中添加不同量组胺对黄颡鱼生长(增重率和特定生长率)无显著影响(P0.05),而高组胺添加量组(H1000组,组胺含量1 390 mg/kg)黄颡鱼皮肤中黑色素含量及脑组织中MC1R mRNA表达量显著低于对照组(P0.05),低添加量组(H10和H100)黄颡鱼皮肤黑色素含量和脑中MC1R mRNA表达量与对照组无差异(P0.05)。随着饲料中组胺添加量的增加,皮肤酪氨酸酶活力呈下降趋势,但各组间差异不显著(P0.05)。结果表明:组胺对黄颡鱼生长表现无影响,但会引起黄颡鱼体色白化,且白化程度与饲料中组胺含量密切相关。

Effect of dietary histamine levels on growth performance and body pigmentation of Pelteobagrus fulvidraco

Effects of histamine levels on the growth performance and body pigmentation of Pelteobagrusfulvidraco were tested via a 56-day culture trial.Four diets had been formulated,including a basal diet with no exogenous histamine inclusion,three diets with increasing histamine added (10,100 and 1 000 mg/kg,respectively) based on diet C.Each diet had been fed to triplicate tanks of P.fulvidraco with an initial weight of (102.13 ±0.52) g which were reared in an in-door micro flow aquaculture system.And the results showed,the histamine level in dietary has no significant effect on growth performance viz.weight gain ratio (WGR,％) and specific growth rate (SGR,％/d).A decreased melanin content in skin and melanocortin 1-receptor (MC1R) mRNA expression quantity in brain were recorded of group fed diet with H1000,though has no significantly change of groups fed with diet H10 and H100,when compared to the group fed with diet C.However,increasing inclusion of histamine has no significant effect on tyrosinase activity of skin,though a decreasing tend was existed with increasing dietary histamine inclusion.To conclude,different histamine inclusion of P.fulvidraco dietary has no significant effect on growth performance,but a dose-dependent effect on skin melanin content and brain MC1R mRNA expression quantity was recorded.