水培大麦苗对湖羊生长性能、瘤胃发酵参数及微生物区系的影响OA

This experiment aimed to investigate the effects of different proportions of hydroponic barley(HB)on the growth performance,rumen fermentation,and rumen microbial community of Hu sheep,and provide a theoretical basis for the application of HB in mutton sheep.Fifty healthy Hu sheep,aged four months and with similar body weight(18.97±1.36 kg),were selected and randomly allocated into five groups,with 10 replicates per group.The groups were supplemented with 0％(control group),5％,10％,15％,and 20％HB to replace the corn stalk and corn silage in the basal diet(on a dry matter basis).The preliminary trial lasted for 15 days,followed by a formal feeding period of 60 days.Body weights were meas-ured at the beginning and end of the experiment,and rumen fluid was collected at the end of the experiment for de-termination of rumen fermentation parameters and rumen microbial community.The results showed that:(1)DMI in the 15％HB and 20％HB groups was significantly lower than that in the CON group(P＜0.05),and F/G in the 10％HB,15％HB,and 20％HB groups was significantly lower than that in the CON and 5％HB groups(P＜0.01).(2)Rumen pH decreased with increasing inclusion of hydroponic barley,with the 20％HB group being significantly lower than the CON,5％HB,and 10％HB groups(P＜0.01).Concentrations of NH3-N,acetate,propionate,butyrate,and TVFA increased with increasing inclusion of hydroponic barley,with the 20％HB group being significantly higher than the other groups(P＜0.01).(3)Compared with the CON group,the relative abundances of Saccharimonadia and Gammacproteobateria in the experimental groups and the 5％HB group significantly decreased(P＜0.05),while the relative abundances of Negativicutes and Ruminococcaceae_UCG_002 in the 10％HB,15％HB,and 20％HB groups significantly increased(P＜0.05).Rumen_bacteri-um showed negative correlations with acetate concentration(P＜0.05,r=-0.497)and TVFA(P＜0.05,r=-0.452).Prevotella showed a significantly negative correlation with A/P(P＜0.05,r=-0.506).Un-classfied_F082 showed negative correlations with propionate concentration(P＜0.01,r=-0.587),pH(P＜0.05,r=-0.490),and A/P(P＜0.01,r=0.580),while Saccharofermentans showed a positive cor-relation with A/P(P＜0.01,r=0.622).In conclusion,supplementing hydroponic barley in the diet can improve the production performance of Hu sheep,regulate rumen fermentation,and alter the rumen mi-crobial community structure,with the optimal proportion being 15％～20％.