title: Relationship between rumen methanogens and methane production in dairy cows fed diets supplemented with a feed enzyme additive.
abstract: OBJECTIVE
  To investigate the relationship between ruminal methanogen community and host enteric methane (CH(4) ) production in lactating dairy cows fed diets supplemented with an exogenous fibrolytic enzyme additive.
  
  
  RESULTS
  Ecology of ruminal methanogens from dairy cows fed with or without exogenous fibrolytic enzymes was examined using PCR-denaturing gradient gel electrophoresis (PCR-DGGE) analyses and quantitative real-time PCR (qRT-PCR). The density of methanogens was not affected by the enzyme additive or sampling times, and no relationship was observed between the total methanogen population and CH(4) yield (as g per head per day or g kg(-1) DMI). The PCR-DGGE profiles consisted of 26 distinctive bands, with two bands similar to Methanogenic archaeon CH1270 negatively correlated, and one band similar to Methanobrevibacter gottschalkii strain HO positively correlated, with CH(4) yield. Three bands similar to Methanogenic archaeon CH1270 or Methanobrevibacter smithii ATCC 35061 appeared after enzyme was added.
  
  
  CONCLUSIONS
  Supplementing a dairy cow diet with an exogenous fibrolytic enzyme additive increased CH(4) yield and altered the composition of the rumen methanogen community, but not the overall density of methanogens.
  
  
  CONCLUSIONS
  This is the first study to identify the correlation between methanogen ecology and host CH(4) yield from lactating dairy cows.
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Zhou
authors.forename: Y-H
authors.initials: YH
authors.lastname: Chung
authors.forename: K A
authors.initials: KA
authors.lastname: Beauchemin
authors.forename: L
authors.initials: L
authors.lastname: Holtshausen
authors.forename: M
authors.initials: M
authors.lastname: Oba
authors.forename: T A
authors.initials: TA
authors.lastname: McAllister
authors.forename: L L
authors.initials: LL
authors.lastname: Guan
mesh_terms: D000818:Animals; D002417:Cattle / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D004798:Enzymes / Q000008:administration & dosage*; D005260:Female; D018628:Gene Dosage; D007774:Lactation; D008697:Methane / Q000096:biosynthesis*; D041581:Methanobrevibacter / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012417:Rumen / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004798:Enzymes; D012336:RNA, Ribosomal, 16S; D008697:Methane