Metabolomics for the sustainability of a meat value chain: application to the Italian heavy pig production system

Italian Protected Designation of Origin (PDO) dry-cured hams produced in Italy constitute a value chain of more than 3 billion € per year. Heavy pigs, slaughtered at about 160 kg of live weight and at 9 months of age, are the animals that produce the raw materials (i.e. the legs) that are then processed to obtain these typical hams. Legs can be properly processed to become PDO hams only if the pigs are raised following some specification rules and derive from a breeding program that has meat and carcass quality traits as its main objectives. These traits are defined by a complex interplay of biological mechanisms and interactions, most of which are still to be defined. Different breeds and lines, and within lines, males (castrated) and females, are characterized by a wide range of variability among these production traits. To understand the basic biological processes underlying economic relevant traits that are routinely evaluated in the Italian heavy pig breeding program, we investigated targeted and untargeted metabolomic profiles of the animals. Plasma from a total of about 800 Italian Large White and Italian Duroc pigs was analysed with targeted and untargeted metabolomic platforms to obtain information from about 1000 metabolites. Data were then initially modelled via univariate and multivariate statistical approaches to identify metabolites characterizing and discriminating the two breeds and the two sexes. Then, metabolomic data were within-breed and sex analyzed via a systems biology approach to obtain biological networks that were further compared to identify breed and sex specific metabolite routes. The obtained results could help to shed new lights on how different genetic backgrounds may explain the basic biological factors that contribute to the variability of meat and carcass quality traits in heavy pigs.