Abstract:
Industrial rearing of insects, especially the black soldier fly, is gaining momentum in recent years because of the increase in food and feed insecurity, high prices of animal feeds and animal proteins, and population growth. This in turn has led to increased global demand for alternative sources of protein apart from traditional livestock products. This study focused on evaluating the gut microbial community dynamics of both the layer and broiler chickens that have been fed on BSF larvae-based diet. The bacterial communities were characterized using high throughput Oxford nanopore sequencing of the full-length bacterial 16S rRNA gene and downstream analysis was done using the QIIME2 pipeline and R software. The layer pullets were allotted 5 dietary treatments that were formulated as follows: control diet (T1): 100% FM + 0% BSFL, T2: 25% BSFL + 75% FM; T3: 50% BSFL + 50% FM; T4: 75% BSFL + 25% FM, and T5: 100% BSFL + 0% FM and the broiler chicken were allotted four dietary treatments, T1 (25% DI + 75% BSFL), T2 (50% DI + 50% BSFL), T3 (75% DI + 25% BSFL) and T4 (100% fishmeal + 0% DI + BSFL). From the findings, it was observed that the predominant phyla in the gut of both the layers and broilers were Firmicutes (90%), Proteobacteria (7%), and Bacteroidetes (2%). At the genus level, the abundant bacteria identified in layer pullets were the Lactobacillus (93%), Enterococcus (2%), Bacteroides (2%), and Blautia (2%) among others. In broilers, the predominant bacteria were Enterococcus (70%), Lactobacillus (25%), and Ruminococcus (3%). A significant increase in the abundance of the beneficial lactic acid-producing bacteria was observed in diets that had BSFL inclusion, especially the Lactobacillus, and Enterococcus. The BSFL-based feeds supported almost similar microbial communities as the conventional fishmeal with changes observed in microbial abundance and this supports the replacement of fishmeal with insect-based feeds without a negative impact on the GIT of chicken. Our findings unravel complex gut microbial shifts in chickens fed BSFL-based feeds and therefore underpins the potential roles of beneficial bacteria identified as promising prebiotics and probiotics in reshaping the gut microbiota to maintain good gut health and improve the overall health status of the birds.