title: The effect of dietary concentrate and soya oil inclusion on microbial diversity in the rumen of cattle.
abstract: OBJECTIVE
  Methane emissions from ruminants are a significant contributor to global greenhouse gas production. The aim of this study was to examine the effect of diet on microbial communities in the rumen of steers.
  
  
  RESULTS
  The effects of dietary alteration (50 : 50 vs 90 : 10 concentrate-forage ratio, and inclusion of soya oil) on methanogenic and bacterial communities in the rumen of steers were examined using molecular fingerprinting techniques (T-RFLP and automated ribosomal intergenic spacer analysis) and real-time PCR. Bacterial diversity was greatly affected by diet, whereas methanogen diversity was not. However, methanogen abundance was significantly reduced (P = 0.009) in high concentrate-forage diets and in the presence of soya oil (6%). In a parallel study, reduced methane emissions were observed with these diets.
  
  
  CONCLUSIONS
  The greater effect of dietary alteration on bacterial community in the rumen compared with the methanogen community may reflect the impact of substrate availability on the rumen bacterial community. This resulted in altered rumen volatile fatty acid profiles and had a downstream effect on methanogen abundance, but not diversity.
  
  
  CONCLUSIONS
  Understanding how rumen microbial communities contribute to methane production and how these microbes are influenced by diet is essential for the rational design of methane mitigation strategies from livestock.
authors.affiliation: Environmental Microbiology Group, School of Biology and Environmental Science, University College Dublin, Dublin, Ireland.
authors.forename: L
authors.initials: L
authors.lastname: Lillis
authors.forename: B
authors.initials: B
authors.lastname: Boots
authors.forename: D A
authors.initials: DA
authors.lastname: Kenny
authors.forename: K
authors.initials: K
authors.lastname: Petrie
authors.forename: T M
authors.initials: TM
authors.lastname: Boland
authors.forename: N
authors.initials: N
authors.lastname: Clipson
authors.forename: E M
authors.initials: EM
authors.lastname: Doyle
mesh_terms: D000818:Animals; D001105:Archaea / Q000145:classification / Q000235:genetics; D001419:Bacteria / Q000145:classification / Q000235:genetics*; D044822:Biodiversity; D002417:Cattle; D016172:DNA Fingerprinting; D019641:DNA, Archaeal / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004032:Diet / Q000662:veterinary*; D005232:Fatty Acids, Volatile / Q000032:analysis; D008297:Male; D008697:Methane / Q000096:biosynthesis*; D012150:Polymorphism, Restriction Fragment Length; D012417:Rumen / Q000382:microbiology*; D013024:Soybean Oil / Q000737:chemistry*
chemical_list: D019641:DNA, Archaeal; D004269:DNA, Bacterial; D005232:Fatty Acids, Volatile; D013024:Soybean Oil; D008697:Methane