Effects of growth rate on carcass and meat quality traits and their association with metabolism-related gene expression in finishing pigs

The objective of this study was to evaluate the effect of different growth rates on carcass characteristics and meat quality and their relationship with myogenesis and lipogenesis in finishing pigs. Pigs were slaughtered at the same age and were assigned to high (HGR) or low (LGR) growth rates with 120 kg or 110 kg final body weights at slaughter. The results indicated that pigs with HGR had heavier (P < 0.05) final body weight, carcass weight, dressing percentage, backfat thickness, higher (P < 0.05) concentrations of fat in the muscle and higher (P < 0.05) total RNA concentration in muscle than pigs with LGR. The messenger RNA (mRNA) expression of lipoprotein lipase, fatty acid synthase, malic enzyme, peroxisome proliferator-activated receptor γ, and sterol regulatory element binding protein-1 in fat were higher (P < 0.05) in pigs with HGR. Additionally, the mRNA expression of glycogen synthase in muscle was lower (P < 0.05) in pigs with HGR. These results indicate differences in postmortem myogenesis and lipogenesis traits of pigs with different growth rates; these differences in turn might have affected carcass characteristics and meat quality.