孕酮对绵羊瘤胃体外发酵和瘤胃微生物区系的影响

Effects of Progesterone on Rumen Fermentation and Rumen Microflora of Sheep in vitro

为了研究孕酮对绵羊瘤胃发酵和瘤胃微生物区系的影响,试验选取3只未妊娠母羊采集瘤胃液,并以全混合日粮(TMR)作为基础发酵底物,分4组(每组5个重复),每组分别添加终质量浓度为0 ng/mL(CK)、1 ng/mL(PL,低浓度组)、8 ng/mL(PM,中浓度组)和22 ng/mL(PH,高浓度组)的孕酮进行发酵,培养48 h后分析瘤胃发酵参数和瘤胃菌群多样性。结果显示,与CK相比,PH组乙酸比例显著降低,PM组丁酸比例显著升高;PL组丙酸比例显著低于PM组,极显著低于PH组;PL组乙酸与丙酸比显著高于PM组和PH组。PL组发酵24 h产气量、有机物降解率和饲料代谢能显著高于CK,极显著高于PH组;PL组潜在最大产气量最高,显著高于CK和PM组,极显著高于PH组。Alpha多样性分析显示,PH组Shannon指数和Simpson指数极显著低于其他3组,ACE指数和Chaol指数CK与其他3组之间差异不显著。Beta多样性分析显示,PH组和其他3组间的微生物菌群多样性差异显著。LEfSe分析发现,与CK相比,孕酮添加组显著降低了动性球菌科(Planococcaceae)、拟杆菌科(Bacteroidaceae)、琥珀酸弧菌科(Succinivibrionaceae)、互养菌科(Synergistaceae)以及Shuttleworthia菌属、假丁酸弧菌属(Pseudobutyrivibrio)、反刍杆菌属(Ruminobacter)、假单胞菌属(Pseudomonas)、乳杆菌属(Lactoba⁃cillus)和Streptococcus minor的相对丰度。孕酮质量浓度影响瘤胃微生物菌群和瘤胃发酵参数,且当孕酮质量浓度为22 ng/mL时瘤胃菌群多样性降低。

The aim of this study was to research the effects of progesterone on rumen fermentation and rumen microflora of sheep.In this study,rumen fluid was collected from 3 non-pregnant ewes and total mixed ration(TMR)was used as the basal fermentation substrate.The experiment was divided into four groups(five replicates per group),and each group was fermented with progesterone at the final mass concentrations of 0 ng/mL(CK),1 ng/mL(PL,low concentration group),8 ng/mL(PM,medium concentration group)and 22 ng/mL(PH,high concentration group),respectively.After 48 h of cultivation,the rumen fermentation parameters and the diversity of rumen microflora were analyzed.The results showed that compared with CK group,the proportion of acetic acid in PH group significantly decreased and the proportion of butyric acid in PM group significantly increased.The proportion of propionate in PL group was significantly lower than that in PM group,and extremely significantly lower than that in PH group.The ratio of acetic acid to propionate in PL group was significantly higher than that in PM group and PH group.Gas production after fermentation for 24 h,organic matter digestibility and feed metabolizable energy in PL group were significantly higher than those in CK group,and extremely significantly higher than those in PH group.The potential maximum gas production in PL group was the highest,significantly higher than that in CK group and PM group,and extremely significantly higher than that in PH group.Alpha diversity analysis showed that the Shannon index and Simpson index of PH group were extremely significantly lower than those in the other three groups.There were no significant differences in ACE index and Chao1 index between CK group and the other three groups.Beta diversity analysis showed that there were significant differences in microflora diversity between PH group and the other three groups.LEfSe analysis found that compared with CK group,the relative abundance of Planococcaceae,Bacteroidaceae,Succinivibrionaceae,Synergistaceae,Shuttleworthia,Pseudobutyrivibrio,Ruminobacter,Pseudomonas,Lactobacillus,and Streptococcus minor was significantly lower in progesterone addition groups.Progesterone mass concentration affected rumen microbial flora and rumen fermentation parameters,and the diversity of rumen microflora decreased when progesterone concentration was 22 ng/mL.