Growth Performance and Meat Quality of Growing Pigs Fed with Black Soldier Fly (Hermetia illucens) Larvae as Alternative Protein Source

Abstract

Insects have been used as animal feed protein sources in livestock and poultry breeding, and their impact on pork quality needs to be studied. This experiment mainly explores the effect of adding black soldier flies to the feed on the growth performance and meat quality of pigs. All 24 weaned piglets were randomly divided into three groups, one group was given a normal diet as the control group (C), and the other two groups were supplemented with 4% (T1) and 8% (T2) black soldier flies as an alternative protein source, respectively. Pig growth performance and carcass traits were measured at the end of the 113-day experiment. After euthanizing the pigs, we used metabolomics to detect pig dorsal muscle and qPCR to detect gene expression in dorsal muscle and adipose tissue. For the average daily gain and backfat thickness, T2 group was significantly higher than T1 group and C group (p < 0.05). Intramuscular fat content was significantly elevated in the T1 and T2 groups (p < 0.05). The metabolomics results showed that there were significant differences in metabolites among the three groups (p < 0.05). The addition of black soldier flies could increase the content of some free amino acids, and the content of lipid metabolites also changed significantly (p < 0.05). The gene expression of type 1 muscle fibers in the T1 group and the PGC-1α gene expression in the T1 and T2 groups were significantly increased in the dorsal muscle (p < 0.05). The results of the present study showed that adding 4% black soldier fly instead of fish meal in the diet of growing pigs can significantly improve meat quality and supplementation of 8% black soldier flies has beneficial effects on growth performance of pigs.