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

Abstract

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(P0.05).HMM had no effect on moisture and crude lipid content(P0.05).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(P0.05).Increasing amounts of HMM were associated with a significant increase in free arginine content(P0.05) and a significant decrease in lysine content(P0.05).The total free amino acid content was significantly higher in G20,but not in G40-G100,than in G0(P0.05).The inclusion of HMM only had an effect on inosine monophosphate(IMP) content at the highest level(G100: P0.05).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(P0.05).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%.