Black Soldier Fly Larvae in broiler diets did not affect performance but decreased cellular immune parameters

Abstract

To evaluate the effects of different inclusion levels of dried Black Soldier Fly larvae (BSF) in broiler diets, five inclusion levels of BSF were investigated in the starter diets (0, 2.5, 5, 7.5 and 10%), and the grower and finisher diets (0, 5, 10, 15 and 20%). Diets were fed to a total of 400 broilers, placed in cages with 8 replicates per treattnent. For the starter (2d to l0d), there was no significant difference in total broiler performance across the treatments. However, during the grower period (lld to 21d), means feed intake (FI), body weight (BW), and feed conversion ratio (FCR) were significantly different across five treatme1f s (ANOVA, P <0.05); broilers with 10% larvae inclusion diet had the highest FCR and the highest Fl. Furthermore, orthogonal polynomial analysis reveals that the FI has a negative quadratic response to graded levels of BSF inclusion (P <0.05). Means white blood cell and lymphocytes were also significantly different in broilers across five treatments (ANOVA test P < 0.05). Those birds with 15% and 20% larvae diets had significantly lower lyinphocytes and white blood cell count compared to the control group (Tukey post hoc test, P <0.001). In tl1e finisher period, there was a significant (P < 0.05) four-fold decrease in cluster of differentiation 3 (CD3+) lyinphocytes and a significant 9.7 fold decrease in the population of CD3+CD8+ intestinal cytotoxic T lymphocytes in birds fed a 20% BSF larval diet compared to the control group. These findings suggest that inclusion of BSF may improve performance and affect the immune status in broilers.