title: The effect of calcium propionate on the ruminal bacterial community composition in finishing bulls.
abstract: OBJECTIVE
  Manipulating the fermentation to improve the performance of the ruminant has attracted the attention of both farmers and animal scientists. Propionate salt supplementation in the diet could disturb the concentration of propionate and total volatile fatty acids in the rumen. This study was conducted to evaluate the effect of calcium propionate supplementation on the ruminal bacterial community composition in finishing bulls.
  
  
  METHODS
  Eight finishing bulls were randomly assigned to control group (CONT) and calcium propionate supplementation (PROP) feeding group, with four head per group. The control group was fed normal the total mixed ration (TMR) finishing diet, and PROP group was fed TMR supplemented with 200 g/d calcium propionate. At the end of the 51-day feeding trial, all bulls were slaughtered and rumen fluid was collected from each of the animals.
  
  
  RESULTS
  Propionate supplementation had no influence the rumen fermentation parameters (p>0.05). Ruminal bacterial community composition was analyzed by sequencing of hypervariable V3 regions of the 16S rRNA gene. The most abundant phyla were theFirmicutes(60.68%) andBacteroidetes(23.67%), followed byTenericutes(4.95%) and TM7 (3.39%). The predominant genera includedSucciniclasticum(9.43%),Butyrivibrio(3.74%),Ruminococcus(3.46%) andPrevotella(2.86%). Bacterial community composition in the two groups were highly similar, except the abundance ofTenericutesdeclined along with the calcium propionate supplementation (p = 0.0078).
  
  
  CONCLUSIONS
  These data suggest that the ruminal bacterial community composition is nearly unchanged by propionate supplementation in finishing bulls.
authors.affiliation: State Key Laboratory of Animal Nutrition, Beijing 100094, China.|College of Animal Science and Technology, China Agricultural University, Beijing 100094, China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Animal Nutrition, Beijing 100094, China.|College of Animal Science and Technology, China Agricultural University, Beijing 100094, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Animal Nutrition, Beijing 100094, China.|College of Animal Science and Technology, China Agricultural University, Beijing 100094, China.
authors.forename: Qingxiang
authors.initials: Q
authors.lastname: Meng
authors.affiliation: State Key Laboratory of Animal Nutrition, Beijing 100094, China.|College of Animal Science and Technology, China Agricultural University, Beijing 100094, China.
authors.forename: Zhenming
authors.initials: Z
authors.lastname: Zhou
keywords: Calcium Propionate; Finishing Bulls; Pyrosequencing; Ruminal Bacterial Community Composition