Effects of dietary inclusion level of microwave-dried black soldier fly (Hermetia illucens) larvae meal on growth performance, cecal volatile fatty acid profiles, and blood parameters in broilers

This study evaluated the effect of microwave-dried black soldier fly (Hermetia illucens) larvae meal (HILM) as a dietary protein source for broiler diets. A total of 250 male broilers were randomly allocated to five dietary treatment groups (10 replicates and 5 birds·pen^-1) which were respectively fed the following: a control diet (HI0) and four experimental diets in which soybean meal was replaced with 2 (HI2), 4, 6, and 8% HILM. At the end of the study (35 d), blood samples were collected from 10 randomly selected broilers (1 bird per pen) to determine serum parameters. Then, the broilers were slaughtered to determine volatile fatty acid (VFA) profiles in cecal digesta. The average daily gain and average daily feed intake linearly decreased (p < 0.01), and the feed conversion ratio linearly increased (p < 0.05) according to the inclusion level of HILM; however, there were no significant differences between the HI0 and HI2 groups. Dietary HILM increased (p < 0.01) the total VFAs in cecal digesta and decreased (p < 0.05) the triglyceride level in the blood. The broilers fed HILM had lower (p < 0.01) serum phosphorus levels; dietary HILM increased (p < 0.05) the serum calcium level. The total VFAs in cecal digesta were positively influenced by the dietary microwave-dried HILM. However, a low inclusion level (2%) of HILM in broiler diets is proper in terms of growth performance and health.