Influence of production system in local and conventional pig breeds on stress indicators at slaughter, muscle and meat traits and pork eating quality.

Sensory quality of pork is a complex phenotype determined by interactions between genetic and environmental factors. This study aimed at describing the respective influences of breed and production system on the development of pork quality. Plasma stress indicators and Longissimus muscle (LM) composition, physicochemical and sensory quality traits were determined in two contrasted breeds - the conventional Large White (LW, n=40) and the French local Basque (B, n=60).

Metabolic adaptation of two pig muscles to cold rearing conditions.

Cold environment represents an external stress modulating animal growth and energy use. At muscle level, adaptation to cold conditions potentially involves energy homeostasis regulation gauged by the adenosine monophosphate (AMP)-activated protein kinase (AMPK). Our study aimed at evaluating the bare effects of short- and long-term cold exposure on growth performance, carcass traits, and metabolic characteristics of the oxidative semispinalis (SS) muscle and glycolytic LM and to evaluate the reversibility of short-term effects, with a special emphasis on AMPK activity.

In vitro characterization of proliferation and differentiation of pig satellite cells.

Skeletal muscle contains various muscle fiber types exhibiting different contractile properties based on the myosin heavy chain (MyHC) isoform profile. Muscle fiber type composition is highly variable and influences growth performance and meat quality, but underlying mechanisms regulating fiber type composition remain poorly understood. The aim of the present work was to develop a model based on muscle satellite cell culture to further investigate the regulation of adult MyHC isoforms expression in pig skeletal muscle.

Consequences of divergent selection for residual feed intake in pigs on muscle energy metabolism and meat quality.

Selection to decrease Residual Feed Intake (RFI) is a relevant way to improve feed efficiency in growing pigs. However, RFI criterion is correlated with body composition and muscle characteristics. Present study evaluated adaptive responses to divergent selection on RFI on muscle metabolism and homeostasis through AMP-activated protein kinase pathway.

Muscle characteristics and meat quality traits are affected by divergent selection on residual feed intake in pigs.

Residual feed intake (RFI) is defined as the difference between the observed feed intake and that expected based on requirements for maintenance and production. A divergent selection was conducted during 4 generations in Large White male pigs to produce low and high RFI lines. The present study aims at determining the influence of this selection on biochemical and histological traits of skeletal muscle, and relating these changes to correlated effects on growth, carcass composition, and meat quality traits.