家蝇蛆粉替代鱼粉对凡纳滨对虾肌肉营养成分、氨基酸和肌苷酸含量的影响

采用等蛋白替代方式,以家蝇蛆粉(housefly maggot meal)分别替代饲料中0、20%、40%、60%、80%和100%的鱼粉,配制6种等氮等能的饲料,饲养初始体质量(0.56±0.03)g的凡纳滨对虾(Litopenaeus vannamei),相应记为G0、G20、G40、G60、G80和G100实验组。养殖45 d后测定对虾肌肉的常规成分和氨基酸、肌苷酸含量,研究家蝇蛆粉对凡纳滨对虾肌肉品质的影响。结果显示,凡纳滨对虾肌肉粗蛋白和灰分含量随家蝇蛆粉替代水平的增加而升高,其中G100组粗蛋白含量和G80、G100组灰分含量显著高于G0组(P<0.05);水分和粗脂肪含量各组之间差异不显著。各组肌肉游离氨基酸中谷氨酸、丙氨酸等鲜味氨基酸和游离鲜味氨基酸总量之间无显著性差异;除G40组外,G20-G100组游离必需氨基酸总量显著高于G0组(P<0.05);与G0组相比,替代组游离精氨酸含量显著增加(P<0.05),游离赖氨酸含量随替代水平的增加而显著降低(P<0.05);G20组游离氨基酸总量显著高于G0组(P<0.05),其他各组之间差异不显著。替代组肌肉结合氨基酸中天冬氨酸、谷氨酸、甘氨酸和丙氨酸等鲜味氨基酸、必需氨基酸和氨基酸总量与G0组相比差异均不显著。G20-G80组肌肉肌苷酸含量与G0组相比差异不显著,G100组显著升高(P<0.05)。结果表明,当家蝇蛆粉替代鱼粉水平不超过60%时,除凡纳滨对虾肌肉游离精氨酸含量显著升高外,对肌肉常规营养成分组成和必需氨基酸、鲜味氨基酸和肌苷酸含量无显著性影响。

Effects of replacement of fish meal with housefly maggot meal on muscle nutritional composition, amino acids, and inosine monophosphate content in juvenile Litopenaeus vannamei

We evaluated the effects of replacing fish meal with housefly maggot meal(HMM) on the nutritional composition,amino acids,and inosine monophosphate content in the muscle of juvenile white shrimp(Litopenaeus vannamei).Six isonitrogenous and isoenergetic diets(G0,G20,G40,G60,G80,and G100) were formu-lated by replacing 0,20%,40%,60%,80%,or 100%,respectively,of the fish meal with HMM(protein basis).The shrimp initial body weight(0.56±0.03) g,were fed the experimental diets for 45 d.There was a positive correlation between crude protein and ash content in the muscle and the proportion HMM in the diet.The crude protein content in G100 and the ash content in G80 and G100 were significantly higher than in the control group(P<0.05).HMM had no effect on moisture and crude lipid content(P>0.05).Similarly,there was no difference in free delicious amino acid(DAA) content(glutamate and alanine only) and total free DAA among the groups.Total free essential amino acid(FEAA) content was significantly higher in groups G40 to G100 than in G0(P<0.05).Increasing amounts of HMM were associated with a significant increase in free arginine content(P<0.05) and a significant decrease in lysine content(P<0.05).The total free amino acid content was significantly higher in G20,but not in G40-G100,than in G0(P>0.05).The inclusion of HMM only had an effect on inosine monophosphate(IMP) content at the highest level(G100: P<0.05).There was no significant difference in the content of combined DAA(aspartate,glutamate,glycine,alanine),EAA,or total amino acids in the muscle of groups fed HMM compared to the control(P>0.05).Overall,inclusion of HMM had no significant effect on the nutritional composition,EAA,DAA,and IMP content in the muscle,with the exception that the free arginine content increased significantly when HMM was substituted at levels below 60%.