The rumen microbial ecosystem during the transition period in dairy cows

Rumen bacteria;Transition cows;Rumen metabolism

Alqarni, Saleh ; Loor ; Juan J.

关键词: Rumen bacteria;    Transition cows;    Rumen metabolism;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/49547/Saleh_Alqarni.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Seven rumen cannulated Holstein cows were used from 3 weeks prepartum to 4 weeks postpartum to determine the relative abundance of 7 different species of ruminal microorganisms. The prepartum diet was based on corn silage. In the postpartum, diet included ground corn, grain by-products, and alfalfa haylage. Ruminal digesta were collected at five times: -14, -7, 10, 20, and 28 days around parturition. Total DNA from ruminal digesta was isolated and real-time quantitative PCR was used to determine the relative abundance of bacterial species. Eubacterium ruminantium and Selenomonas ruminantium were not affected by time (P>0.05). Megasphaera elsdenii and Prevotella bryantii increased significantly postpartum (P<0.001). Conversely, Butyrivibrio proteoclasticus decreased gradually from -14 through 28 days (P<0.001). Fibrobacter succinogenes was affected by time being lowest at day 10 (P=0.02) whileAnaerovibrio lipolytica recorded the lowest abundance at -7 d followed by an increase by 20 days postpartum (P<0.001). Overall, these results indicate that changes in diet after parturition affect the abundance of ruminal bacteria, particularly M. elsdenii (a lactate-utilizing bacteria) and P. bryantii (a starch-degrading bacteria) which increased markedly after parturition likely as a consequence of a higher concentrate intake. In terms of milk production, there was a relative decrease in the body weight of dairy cows.The milk yield increased considerably up to the fourth week, while the percentage of fat was reduced considerably.