Effects of sugarcane bagasse and pineapple residue on the growth,development,and gut microbiota of black soldier fly larvae
This study aims to investigate the effects of feeding black soldier fly(BSF)larvae with sugarcane bagasse and pineapple peel on their growth performance and gut microbiota.The experiment used unfermented and naturally fermented sugarcane bagasse and pineapple peel as base feed materials,supplemented with different proportions of tofu residue to create various feed formulations for feeding BSF larvae.The growth performance and gut microbiota of the BSF larvae were then measured.The results showed that compared to the control(CK),which used pure tofu residue as the base feed,treatment Ⅳ(80%fermented pineapple peel+20%tofu residue)significantly improved the average body length,weight,growth performance,and feed efficiency of the BSF larvae before they became prepupae,while reducing the feed conversion ratio(FCR).After 7 days of rearing,the average body length,weight,biomass gain,growth rate,and feed efficiency of larvae in treatment Ⅳ were 11.58%,46.69%,47.12%,46.75%,and 24.10%higher than those in CK,respectively,with the FCR reduced by 19.18%.Compared to treatments Ⅰ and Ⅲ,which used unfermented fruit residues as base feed,treatments Ⅱ and IV improved the average body length,weight,larval growth rate,and feed efficiency of the BSF larvae before prepupation,and reduced the FCR.The gut microbiota of BSF larvae clustered well.In treatments Ⅰ~Ⅳ,the average relative abundance of the phylum Bacteroidetes in the larvae's gut was significantly higher than in CK,while the average relative abundance of the phylum Firmicutes in treatments Ⅱ~Ⅳ was significantly lower than in CK.The average relative abundance of Firmicutes in treatment Ⅰ was lower than in CK but not significantly so.Compared to CK,the relative abundance of the genus Enterobacter in the gut of BSF larvae in treatments Ⅰ~Ⅳ increased significantly(over 40.10%),while the relative abundance of the genus Enterococcus decreased significantly.The relative abundance of the genera Morganella and Actinomyces decreased but not significantly,while the relative abundance of the genus Providencia increased but not significantly.The study indicated that treatment IV led to better growth performance and feed conversion efficiency in BSF larvae compared to other treatments,with fermented fruit residue treatments outperforming unfermented treatments.Additionally,different feed formulations caused changes in the relative abundance of the gut microbiota in BSF larvae.