Quality of PDO Noir de Bigorre pork products according to pig feeding and season in extensive system

The Noir de Bigorre (NB) pork chain relying on pure Gascon autochtonous breed obtained in 2015 the FrenchAOC label required for further European Protected Designation of Origin (PDO) registration, for both fresh meat and dry-cured hams. Pigs produced in extensive conditions (pasture, 20 pigs/ha) consume large quantities of grass and, depending on the season, acorns and chestnuts in addition to a conventional diet. Variations in feed resources and climatic conditions along the fattening period can modulate animal growth, muscle and fat tissue traits and the intrinsic properties of pork products. Within the European H2020 TREASURE project, we aimed at better characterizing the variability of various phenotypic traits of pork and processed products from NB chain according to the pig finishing season. Gascon castrated male pigs were produced in compliance with PDO specifications in two farms of the NB chain with similar husbandry practices and slaughtered at the end of winter (W, n=25) or spring (S, n=23). Season influenced carcass and meat traits. At similar slaughter weight and age (166.5 kg and 414 d on average), S pigs exhibited slightly lower carcass fatness (P<0.10) but higher lipid content in the Gluteus (ham) muscle (3.44 vs 2.79%, P<0.001) than S pigs. In loin and ham muscles, S pigs showed higher ultimate pH (+0.06 to 0.15 units, P<0.01) and lower meat lightness (P<0.05) and hue angle (P<0.10), indicating redder meat, than W pigs. Season associated to feed resources affected tissue lipid profile with higher (P<0.05) n-3 polyunsaturated fatty acid content and lower (P<0.001) n6-/n-3 ratio in Gluteus muscle and external fat of green hams from S pigs, underlying the positive effect of pig grass consumption during spring on the nutritional value of pork. Present and future results on quality of fresh pork and dry-cured hams from pigs slaughtered at the end of autumn following acorns consumption will be useful for actors of the local NB chain to adapt pig husbandry practices, in order tofurther improve the eating quality and differentiation of pork products within PDO specifications.