缓释包被尿素对藏西北绒山羊瘤胃组织形态、蛋白酶活性及微生物多样性的影响OA

To investigate the effects of slow-released urea on rumen morphology,proteinase activity and microbial diversity of Tibetan cashmere goats,thirty 15-month-old Tibetan cashmere goats(half male and half female)were divided into 3 groups with 10 replicates per group and 1 sheep per replicate according to single factor level.They were divided into control group,urea group(2％)and slow-released urea group(2.4％).The pre-test period lasted for 7 days and the trial period lasted for 49 days.The results showed as follows:(1)the rumen papillary height and keratin thickness in urea group were lower than those in con-trol group and slow-released urea group(P＜0.05).(2)The rumen protease activity and pepsin activity in slow-released urea group were higher than those in control group and urea group(P＜0.05).(3)Com-pared with control group and slow-released urea group,the relative abundance of Actinobacteriota,Chlo-roflexi(P＜0.01)and Firmicutes(P＜0.05)in urea group was increased and Bacteroidota was decreased(P＜0.05).The rumen of cashmere goats in the slow-released urea group had higher relative abundance of Patescibacteria than that in the control group and the urea group(P＜0.01),and the rumen of cashmere goats in the control group had higher relative abundance of Verrucomicrobiota than that in the urea group and the slow-released urea group(P＜0.05).Compared with the control group and the slow-released urea group,the relative abundance of Christensenellaceae_R-7_group in urea group(P＜0.01),Firmicutes_un-classified and NK4A214 group(NK4A214_group)were increased(P＜0.05),while Rikenellaceae_RC9_gut_group(P＜0.01)and Prevotella(P＜0.05)were decreased.The rumen of cashmere goats in the urea group had lower relative abundance of bacteria F082 than that in the control group(P＜0.05).The relative abundance of Candidatus_Saccharimonas in slow-released urea group was higher than that in control group and urea group(P＜0.01).In conclusion,dietary urea supplementation changed rumen microflora structure of cashmere goats.Compared with urea,dietary supplemented with slow-released urea could in-crease rumen protease activity,and has no negative effect on rumen development of cashmere goats.