China Animal Husbandry and Veterinary Medicine ›› 2021, Vol. 48 ›› Issue (4): 1251-1263.doi: 10.16431/j.cnki.1671-7236.2021.04.012

• Animal Nutrition and Feed Science • Previous Articles     Next Articles

Effects of Dietary Crude Fiber Level on Rumen Microbial Composition and Diversity of Fattening Lambs

LI Xi, MAO Yangyi, LUO Huidi, ZHAO Peng, LI Jun, ZHANG Li, LI Chunyan, WANG Honghao   

  1. College of Animal Sciences, Shanxi Agricultural University, Taiyuan 030032, China
  • Received:2020-09-18 Online:2021-04-20 Published:2021-04-16

Abstract: This experiment was conducted to investigate the effects of dietary crude fiber level enhancement on rumen microbial composition and diversity of fattening lambs.In this study,healthy and disease-free male lambs were selected.All lambs with similar weight at the age of 2 months were randomly divided into two groups according to the body weight,38 males in each group were fed with different diets.The diets of control group were composed of concentrate and alfalfa hay,while the diets of the treatment group were composed of whole corn silage and peanut seedling based on control group diet.The period of trial lasted 150 d,including 20 d in the preliminary phase.After the end of the experiment,5 lambs from each group were slaughtered,and rumen contents were collected for the measurement of microbial diversity and structural changes by 16S rDNA high-throughput sequencing technology.The results showed that the bacterial diversity in the rumen of the treated lambs was significantly higher than that of the control group (P<0.05).At the level of phylum,the dominant bacteria in the rumen of the lambs in the treatment group were Bacteroidetes and Firmicutes,while the dominant bacteria in the control group were Bacteroidetes and Proteobacteria.After the addition of fiber,the relative abundance of Firmicutes in the rumen of the fattening lambs was significantly increased (P<0.05),the relative abundance of Proteobacteria was significantly reduced (P<0.05).At the level of genus,195 genera were identified from the rumen bacteria of the control group and the treatment group,and the dominant bacteria in the treatment group were Prevotella_1 and Succiniclasticum,while the dominant bacteria in the control group were Succinivibrionaceae and Prevotella_7.The relative abundance of Succiniclasticum,Treponema_2,Ruminococcaceae and Selenomonas_1 in the rumen of fattening lambs was increased by increasing the dietary fiber level,and the relative abundance of Succinivibrionaceae was significantly reduced (P<0.05).Therefore,the increase of dietary fiber level appropriately had a certain effect on the structure of rumen microbial flora of fattening lambs,which could promote the proliferation of some fiber-degrading bacteria,and was beneficial to rumen fermentation and nutrient digestion and utilization of fattening lambs.

Key words: rumen microorganisms; diversity; fattening lamb; 16S rDNA

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