43 Feed efficiency and behavior are associated with gut microbiome in three breeds of pigs

Feed efficiency and behavior are important traits in the pork industry for economic, welfare, and environmental aspects. The gut microbiota plays an important role in nutrient digestibility and it is likely to influence these traits. The aim of this study was to characterize the feed efficiency, feeding behavior and gut microbiome relationships of pigs belonging to three different breeds. Individual body weight, feed intake and rate of Duroc (n = 222), Landrace (n = 244), and Large White (n = 221) pigs were recorded. Rectal fecal samples were collected from each animal at three time points (T1, start of trial; T2, mid-trial; T3, end of trial) and used for microbiome 16S rRNA gene sequencing. Individual feed intake and body weight were edited to obtain average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR), average daily feeding rate (ADFR), average feed intake per visit (AFIV), average daily number of visits to feeder (ANVD), average daily occupation time (AOTD), average occupation time per visit (AOTV). The impact of gut microbiome on the traits studied was present and seemed to depend on the breed and the time point of recording. At T1, Oscillibacter and Phascolarctobacterium had negative impact on ANVD and ADFI in Duroc, Ruminococcus had negative impact on ADFI in Landrace and Parvimonas, Escherichia and Anaerovibrio had negative impact on ADFI and ANVD in Large White. At T2, Lactobacillus showed a positive impact on ADFR in Landrace and on ADFI in Large White. At T3, Ruminococcus, Faecalibacterium and Dorea had a positive impact on ADFI in Duroc, Staphylococcous had positive impact on ADFR in Landrace and Peptoniphilus had negative impact on ADFI in Large White. Gut microbiome may have an heterogenous impact on the regulation of feeding behavior and feed efficiency depending on the host genotype.