Metabolomics identified new biomarkers to help describing feed efficiency in Italian Large White pigs

Improving feed efficiency in the swine industry is a key strategy for enhancing the sustainability and cost-effectiveness of this sector. In fact, as the pig grows toward market weight, it becomes less efficient at converting feed into body weight gain, as more energy is required from the organism to manage the basic biological functions. This is particularly relevant for the Italian heavy pig sector that is characterised by high slaughter weights and significant feed costs. This study applies untargeted metabolomics to explore feed efficiency in Italian heavy pigs. Here, feed conversion ratio (FCR) and average daily gain (ADG), the two primary metrics of efficiency, were evaluated using plasma metabolomics. Over 700 Italian large White pigs, with random residuals retrieved from genetic indexes routinely collected for selection purposes was used to generate two distinct pools (one for FCR and one for ADG). Each pool contained animals with extreme and divergent values for the trait of interest. Using untargeted metabolomic profiling of plasma, 722 metabolites were identified, with 662 of endogenous origin. Machine learning approaches (i.e. Boruta algorithm) identified discriminant metabolites within groups associated with FCR and ADG. For FCR, 11 key metabolites spanning lipid, amino acid, and peptide pathways were highlighted. For ADG, eight metabolites were identified, with notable changes in lipids and amino acids. Only one unknown metabolite was detected for both groups. The heritability of the selected metabolites ranged from 0.08 to 0.33. Functional analysis revealed metabolic pathways linked to energy production, lipid metabolism, and amino acid turnover as key drivers of feed efficiency. Principal component and random forest analyses further underscored the predictive power of these metabolites for differentiating high and low efficiency groups. The findings provide a foundation for integrating metabolomic biomarkers into precision breeding and selection strategies, ultimately enhancing the efficiency and sustainability of Italian heavy pig production. This project has received funding from the European Union – NextGenerationEU under the National Recovery and Resilience Plan (PNRR) – Mission 4 Education and research – Component 2 From research to business – Investment 1.1 Notice PRIN 2022 PNRR (DD N. 1409 del 14 / 09 / 2022), from FEEDTHEPIG, proposal code P2022FZMJ9 – CUP J53D23018310001.