不同水平苜蓿叶粉对妊娠母猪粪便体外发酵特性及菌群结构的调控作用OA

In this study,an in vitro fermentation model was constructed using fecal microbiota from gestating sows as the inoculum to investigate the effects of different levels of alfalfa leaf meal(ALM)on gas production,short-chain fatty acids(SCFAs)production,and microbial community composition under different fermentation times.This approach aims to optimize feed formulation to improve sow intestinal health and reproductive performance,reduce environmental pollution,and enhance economic benefits.Fecal microbiota from healthy gestating sows were used as the inoculum,and ALM was selected as the fermentation substrate.Four ALM levels were applied:0 mg(CON),50 mg(LALM),100 mg(MALM),and 200 mg(HALM).Fermentation broth and substrate residues were collected at 8,12,24,and 36 h for the determination of gas production,SCFAs yield,and microbiota composition.The results showed that total gas production and total SCFAs content in the fermentation broth at each time point tended to increase with increasing ALM levels.The addition of ALM significantly reduced H2S production(P<0.05).Acetic acid content increased significantly(P<0.01)following ALM addition,while valeric acid,isobutyric acid,and isovaleric acid contents were significantly increased(P<0.01)after 12 h of fermentation.Compared with the control group,the relative abundance of Fusobacterium was significantly reduced(P<0.05),whereas the relative abundance of Collinsella,Prevotellaceae_NK3B31_group,and Actinobacteriota was significantly increased(P<0.05)following ALM addition.The relative abundances of Prevotella,Olsenella,and Holdemanella exhibited significant positive correlations with fermentation gas production and short-chain fatty acids,while the former two genera showed highly significant negative correlations with H2S(P<0.01).In summary,supplementation with ALM in the in vitro fermentation of gestating sow fecal microbiota improved microbial community structure,promoted SCFAs production,and increased H2,CH4 and CO2 production.