title: Rumen microbial population dynamics in response to photoperiod.
abstract: OBJECTIVE
  This work was carried out to determine if there was a difference in the microbial population of the rumen associated with daylength at which sheep are housed.
  
  
  RESULTS
  Denaturing gradient gel electrophoresis (DGGE) was used to study the ciliate and bacterial diversity in the rumen of Soay rams kept in long day (16 h light) or short day (8 h light) photoperiods. Bacterial diversity varied according to the daylength conditions where the host animal was housed, as did total volatile fatty acids (VFA) concentrations. No differences associated with daylength were detected in ciliate diversity, branched VFA concentrations or the ruminal ammonia concentrations.
  
  
  CONCLUSIONS
  As diets had identical composition, yet voluntary intakes levels were higher during long days, it is proposed that the differences in bacterial populations arise because of the differences in amount of food consumed.
  
  
  CONCLUSIONS
  The outcome of this study demonstrated that factors beyond dietary composition must be taken into account when trying to study microbial populations, even in what can be considered a fairly constant environment.
authors.affiliation: Gut Microbiology and Immunology Division, Rowett Research Institute, Aberdeen, UK. n.mcewan@rowett.ac.uk
authors.forename: N R
authors.initials: NR
authors.lastname: McEwan
authors.forename: L
authors.initials: L
authors.lastname: Abecia
authors.forename: M
authors.initials: M
authors.lastname: Regensbogenova
authors.forename: C L
authors.initials: CL
authors.lastname: Adam
authors.forename: P A
authors.initials: PA
authors.lastname: Findlay
authors.forename: C J
authors.initials: CJ
authors.lastname: Newbold
mesh_terms: D000818:Animals; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis; D004435:Eating / Q000502:physiology; D004591:Electrophoresis, Polyacrylamide Gel; D017440:Photoperiod; D012417:Rumen / Q000737:chemistry / Q000382:microbiology* / Q000502:physiology; D012756:Sheep / Q000382:microbiology* / Q000502:physiology; D013997:Time Factors
chemical_list: D004269:DNA, Bacterial