title: Microbial composition in different gut locations of weaning piglets receiving antibiotics.
abstract: OBJECTIVE
  The aim of this study was to examine shifts in the composition of the bacterial population in the intestinal tracts (ITs) of weaning piglets by antibiotic treatment using high-throughput sequencing.
  
  
  METHODS
  Sixty 28-d-old weaning piglets were randomly divided into two treatment groups. The Control group was treated with a basal diet without antibiotics. The Antibiotic group's basal diet contained colistin sulfate at a concentration of 20 g per ton and bacitracin zinc at a concentration of 40 g per ton. All of the pigs were fed for 28 days. Then, three pigs were killed, and the luminal contents of the jejunum, ileum, cecum, and colon were collected for DNA extraction and high-throughput sequencing.
  
  
  RESULTS
  The results showed that the average daily weight gain of the antibiotic group was significantly greater (p<0.05), and the incidence of diarrhea lower (p>0.05), than the control group. A total of 812,607 valid reads were generated. Thirty-eight operational taxonomic units (OTUs) that were found in all of the samples were defined as core OTUs. Twenty-one phyla were identified, and approximately 90% of the classifiable sequences belonged to the phylum Firmicutes. Forty-two classes were identified. Of the 232 genera identified, nine genera were identified as the core gut microbiome because they existed in all of the tracts. The proportion of the nine core bacteria varied at the different tract sites. A heat map was used to understand how the numbers of the abundant genera shifted between the two treatment groups.
  
  
  CONCLUSIONS
  At different tract sites the relative abundance of gut microbiota was different. Antibiotics could cause shifts in the microorganism composition and affect the composition of gut microbiota in the different tracts of weaning piglets.
authors.affiliation: Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.|College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Kaifeng
authors.initials: K
authors.lastname: Li
authors.affiliation: Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
authors.forename: Yingping
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Jiucheng
authors.initials: J
authors.lastname: Chen
authors.affiliation: Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
authors.forename: Jinggang
authors.initials: J
authors.lastname: Chen
authors.affiliation: Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
authors.forename: Xiangxiang
authors.initials: X
authors.lastname: He
authors.affiliation: Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
keywords: Antibiotics; Growth Performance; Gut Microbiota Diversity; MiSeq; Weaning piglets