不同饲养方式对牦牛瘤胃发酵参数及微生物菌群的影响

Effects of Different Feeding Methods on Rumen Fermentation Parameters and Microbial Flora of Yaks

本研究旨在比较不同饲养方式对牦牛瘤胃发酵参数及微生物菌群的影响。试验选取3周岁、体重[(176.3±14.7)kg]相近、体况良好的公牦牛20头,随机分为舍饲组(全混合日粮)和放牧组(放牧),每组10头牛。预试期10 d,正试期90 d。结果表明:1)舍饲组瘤胃总挥发性脂肪酸(TVFA)、乙酸、丙酸、丁酸浓度显著高于放牧组(P<0.05),而瘤胃pH显著低于放牧组(P<0.05)。2)舍饲组瘤胃微生物菌群Chao1指数显著高于放牧组(P<0.05)。3)在门水平上,舍饲组瘤胃Saccharibacteria、迷踪菌门(Elusimicrobia)、拟杆菌门(Bacteroidetes)、螺旋体门(Spirochaetae)、软壁菌门(Tenericutes)相对丰度显著高于放牧组(P<0.05),而放牧组瘤胃浮霉菌门(Planctomycetes)、互养菌门(Synergistetes)和厚壁菌门(Firmicutes)相对丰度显著高于舍饲组(P<0.05)。在属水平,舍饲组瘤胃Candidatus_Saccharimonas、醋酸杆菌属(Acetobacter)、螺旋体属_2(Spirochaeta_2)、凸腹真杆菌属(Eubacterium_ventriosum_group)和乳酸杆菌属(Lactobacillus)相对丰度显著高于放牧组(P<0.05),而放牧组瘤胃罗斯氏菌属(Rosebuna)、狭义梭菌属(Clostridium_sensu_stricto_1)、Family-ⅩⅢ-AD3011、丁酸弧菌属_2(Butybrivibrio_2)和奎因氏菌属(Quinella)相对丰度显著高于舍饲组(P<0.05)。4)利用PICRUSt预测瘤胃微生物的代谢途径和功能,在KEGG2水平,舍饲组能量代谢(energy metabolism)、核苷酸代谢(nucleotide metabolism)、转录(transcription)、运输和分解代谢(transport and catabolism)基因家族相对风丰度显著高于放牧组(P<0.05)。综上所述,与放牧相比,全混合日粮舍饲育肥提高了牦牛瘤胃内非纤维物质的降解菌以及半纤维降解菌属的相对丰度,同时增加了VFA浓度,并且牦牛的能量代谢通路上调,促进了牦牛的高效代谢,有助于加快牦牛的生长发育。

The objective of this study was to compare the effects of different feeding methods on rumen fermentation parameters and microbial flora of yaks.In the experiment,twenty 3-year-old male yaks with similar body weight[(176.3±14.7)kg]and good body condition were selected,and randomly divided into barn feeding group(total mixed ration)and herding group(grazing),each group contained 10 yaks.The pretrial period lasted for 10 days and the trial period lasted for 90 days.The results showed as follows:1)the concentrations of total volatile fatty acid,acetic acid,propionic acid and butyric acid in rumen of barn feeding group were significantly higher than those of herding group(P<0.05),while rumen pH was significantly lower than that of herding group(P<0.05).2)The rumen microbial flora Chao1 index of barn feeding group was significantly higher than that of herding group(P<0.05).3)At the phylum level,the relative abundances of Saccharibacteria,Elusimicrobia,Bacteroidetes,Spirochaetae and Tenericutes in rumen of barn feeding group were significantly higher than those of herding group(P<0.05),while the relative abundances of Planctomycetes,Synergistetes and Firmicutes in rumen of herding group were significantly higher than those of barn feeding group(P<0.05).At the genus level,The relative abundances of Candidatus_Saccharimonas,Acetobacter,Spirochaeta_2,Eubacterium-ventriosum_group and Lactobacillus in rumen of barn feeding group were significantly higher than those of herding group(P<0.05),while the relative abundances of Rosebuna,Clostridium_sensu_stricto_1,Family-ⅩⅢ-AD3011,Butybrivibrio_2 and Quinella in rumen of herding group were significantly higher than those of barn feeding group(P<0.05).4)Using PICRUSt to predict the metabolic pathways and functions of rumen microorganisms,in KEGG2 level,the relative abundances of energy metabolism,nucleotide metabolism,transcription,transport and catabolism the related gene family of barn feeding group was significantly higher than those of herding group(P<0.05).In conclusion,compared with grazing,the total mixed ration barn feeding increase the relative abundances of non-fibrous substance degrading bacteria and hemi-fibrous degrading bacteria in rumen of yaks,and at the same time increase the concentration of VFA,and the energy metabolism pathway of yak was up-regulate,promoted the efficient metabolism of yaks,which helps to accelerate the growth and development of yaks.