Defatted black soldier fly (Hermetia illucens) larvae meal can partially replace fish meal in diets for adult Chinese soft-shelled turtles

Abstract

The aim of this study was to analyze the feasibility of partial replacement of fish meal (FM) with defatted black soldier fly larvae meal (BSFLM) in the diet of Chinese soft-shelled turtles by determining the growth performance, serum biochemical indices, antioxidant capacity, proximate composition, and amino acid profile. The turtles were divided into five groups (G1, G2, G3, G4, and G5) and fed with diets in which 0, 5%, 10%, 15%, and 20% FM was replaced with BSFLM, respectively. The growth performances of the turtles in the G2 and G3 groups were the same as those in the G1 group (P > 0.05), whereas the feed conversion ratio of the G3 group was significantly decreased (P < 0.05). The activity of alkaline phosphatase was significantly higher in the G3 group than that in the G1, G2, and G4 groups (P < 0.05), and the activity of alanine aminotransferase was significantly lower in the G2 and G3 groups than that in the G5 group (P < 0.05). Glutathione peroxidase activity in the serum and total antioxidant capacity in the liver significantly increased in the G3, G4, and G5 groups when compared with the G1 group (P < 0.05), and malonaldehyde levels in the serum and liver showed a linear decrease (P = 0.015 and P = 0.040, respectively) with increasing BSFLM levels in the diets (P < 0.05). The levels of crude protein in the muscle were significantly higher in the G3 and G4 groups than that in the G1 and G2 groups (P < 0.05). The levels of crude fat in the muscle and calipash showed a linear increase (P = 0.000 and P = 0.000, respectively) with increasing BSFLM levels (P < 0.05), whereas the levels of ash showed the opposite trend. Phenylalanine, tryptophan, glutamic, and arginine levels in the muscle and calipash were significantly lower in the other groups than that in the G1 group (P < 0.05), whereas isoleucine level showed the opposite trend. The results showed that the replacement of 10% dietary FM with BSFLM is feasible for Chinese soft-shelled turtles, and it has a positive influence on growth performance, antioxidant capacity, and nutritional value.