Effects of defatted black soldier fly larvae meal as a replacement for soybean meal on growth performance, health, intestinal morphology and cecal microbiota of broiler chickens
摘要
This study investigated the effects of replacing soybean meal (SBM) with black soldier fly larvae meal (BSFL) on the performance, carcass yield, blood biochemistry, hematology, and organ histology of broiler chickens. A total of 250 one-day-old Ross chicks were randomly allocated into five dietary treatments, with 5 replicates of 10 birds each, according to the following experimental design: a control group fed a basal diet (T1), and four groups with dietary replacement of SBM by 25% BSFL (T2), 50% BSFL (T3), 75% BSFL (T4), and 100% BSFL (T5). All groups were maintained under identical management and environmental conditions. At the end of the 35-day experimental period, the broilers were slaughtered, dressed, and weighed. The results showed that the 25% substitution level (T2) gave the best results, significantly improving body weight, weight gain, and the feed conversion ratio (FCR) with normal feed intake. The 50% group (T3) maintained a stable carcass weight similar to the control but showed lower feed intake. In contrast, higher levels (75% and 100%) decreased growth performance and carcass quality due to the high chitin content in the insect exoskeleton. Blood profiles and liver enzymes (ALT and AST) remained normal in most groups, confirming that the diet was safe. However, the 100% group (T5) showed higher cholesterol and HDL levels, and a lower albumin-to-globulin (A/G) ratio. Tissue analysis revealed only mild, non-pathogenic immune responses in the liver and lymphoid organs. Furthermore, BSFL did not alter the cecal microbial balance, maintaining normal Lactobacillus spp. and coliform counts, and all groups remained Salmonella-free. In conclusion, these findings indicate that BSFL can safely replace up to 50% of dietary SBM without compromising broiler health, development, or physiological status. This establishes BSFL as a viable, sustainable alternative protein source capable of reducing reliance on traditional soybean meal in poultry production, provided inclusion rates are optimized to prevent nutritional imbalances at higher substitution levels.
Graphical Abstract