Longitudinal Analysis of the Microbiota Composition and Enterotypes of Pigs from Post-Weaning to Finishing.

The present study aimed at investigating the evolution of pigs' fecal microbiota composition from post-weaning to finishing in a longitudinal analysis. The experiment was conducted on 160 Pietrain × (Large White × Landrace) castrated male and female pigs in two replicates. Feces were collected at 52, 99, 119, 140, and 154 days of age for further 16S rRNA sequencing to analyze the microbiota composition. Pig microbiota evolved strongly from 52 to 99 days of age with an increased abundance of Streptococcaceae and a decreased abundance of Lactobacillaceae. During the finishing stage, microbiota kept evolving at a slower rate. To link the community structure to the performances, the fecal samples were clustered into enterotypes sharing a similar bacterial composition. At 52 days, two enterotypes dominated either by or by - were identified. They differed from the two enterotypes determined from 99 to 154 days which were dominated either by or by -. During this time period, 75% of the pigs switched enterotypes. The enterotypes were not related to differences in the overall growth or feeding performance. The enterotype definition was time-dependent and seemed to be related to the sex type at 99 days of age.