Gut microbiota composition of Turopolje pigs in outdoor production and acorn supplementation

The Turopolje pig is a local porcine breed originating from Croatia characterised by its rusticity and adaptation to the traditional outdoor farming system linked to local oak forests. While this once-widespread breed was almost completely replaced by industrial breeds in the second half of the 20th century, there is growing interest on promoting its production in the framework of sustainable porcine production. The objective of our study was to characterise the gut microbiota composition in 24 Turopolje pigs raised outdoor by using a conventional feed and a conventional feed supplemented with acorns. The gut microbiota composition of all pigs was determined by re-sequencing the bacterial 16S gene in an Illumina MiSeq. Bioinformatics analyses were performed by using Qiime’s open-reference OTU calling subsampled method following author’s recommendations. NMDS and PERMANOVA analyses performed by using the Vegan R package showed significant effects of diet, showing that the acorn supplementation has a relevant impact on gut microbiota, notably by reducing richness and diversity. This result was confirmed in differential abundance analysis that showed that 152 out of 1466 OTUs were significantly different between the two groups. Interestingly, the predicted microbiota metabolic functions that were differentially abundant involved fatty acid and amino-acid metabolisms. Funded by European Union’s H2020 RIA program (Grant agreement No 634476).