Caratterizzazione del microbiota fecale di suini di razza Nero Siciliano alimentati con integrazione di siero di latte liquido fresco

The study of the gut microbiome is considered a relevant tool due to the impact of this research field on host health, well-being and growth. In this field, the research has shown a rapid increase favoured by overcoming the technological limits of classical microbiology through the development of next-generation sequencing platforms that allowed the simultaneous study at a high resolution of the microbial communities. The present PhD thesis is part of an industrial PON research project aimed at characterizing the faecal microbiota profile of Nero Siciliano pigs after a dairy co-feed integration. Liquid feeding is an alternative practice employed in swine production that allows the recovery of low-cost liquid by-products to reduce the environmental impact. This type of feeding can positively affect an animal's gut health, well-being and performance. Liquid whey is a palatable feed, representing a resource to administer ingredients without additional costly processes. In this view, this study investigated the faecal microbiota of eleven pigs belonging to the Nero Siciliano breed after a liquid whey co- feed supplemented diet using a metagenomics approach. The administration of by- products as animal feed, especially in swine production, is a strategy to provide functional ingredients to improve gut health. Therefore, to explore the potential effect of a liquid whey-supplemented diet on the faecal microbiota, five pigs were assigned to the control group and fed with a standard formulation feed, and six pigs to the experimental group fed with the same feed supplemented with fresh liquid whey. Faecal samples were collected from each individual before the experimental diet (T0) and one (T1), and two (T2) months after the beginning of the co-feed integration. Taxonomic analysis based on the V3–V4 region of the bacterial 16S rRNA showed that pig faeces were populated by a complex microbial community with a remarkable abundance of Firmicutes, Bacteroidetes and Spirochaetes phyla and Prevotella, Lactobacillus, Clostridium and Treponema genera. Alpha and beta diversity values suggested that the experimental diet did not significantly affect the general faecal microbiota diversity. However, time points differential abundance analysis revealed significant variation for several bacterial genera, thus suggesting that the experimental diet potentially affected some genera of the microbial community over time.