This study was conducted to determine the effect of dietary carnosine (β-alanyl-L-histidine) supplementation on antioxidant capacity and meat quality of pigs. 72 pigs approximately 60 kg were fed a corn- and soybean meal-based diet supplemented with 0, 25, 50 or 100 mg carnosine per kg diet for 8 weeks. Carnosine supplementation did not affect growth performance and carcass traits of pigs. However, the addition of 100 mg carnosine per kg diet increased pH value of muscle at 45 min, 24 h and 48 h postmortem. It also decreased drip loss at 48 h postmortem and increased redness value of muscle at 45 min postmortem (p < 0.05). The addition of 100 mg carnosine per kg diet enhanced glycogen concentration and Ca-ATPase activity at 24 and 48 h postmortem, and reduced malondialdehyde and carbonyl protein complexes concentrations in muscle at 24 h postmortem (p < 0.05). The addition of 100 mg carnosine per kg diet increased glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) activities in plasma, liver or muscle, as well as SOD and GSH-Px genes expression in muscle (p < 0.05). Taken together, these findings indicate that carnosine supplementation improves antioxidant capacity and meat quality of pigs.

The uneven development of adipose tissues reflects a differential occurrence of biological events in vivo while the underlying molecular mechanism remains largely unknown. In the present study, the in vivo inflammatory status of an inbred obese porcine model, Lantang pig, was assessed, aiming to provide evidence for obesity biology. Compared with genetically lean pigs (crossbred, Duroc × Landrace × Large White), Lantang pigs exhibited a larger amount of ultra large adipocytes in subcutaneous adipose tissue accompanied with higher expression of macrophage/monocytes markers and pro-inflammatory genes (TLR4, CD14, CD11β, MCP1, TNFα, IL1β and IL6) and lower expression of cellular antioxidant enzymes (SOD1, 2 and 3). Plasma concentrations of LPS and TNF-α were also higher in Lantang pigs than in lean pigs. Among adipose tissues of Lantang pigs, the subcutaneous tissue had the most abundant expression of inflammation related genes (TLR4, CD14, TNFα and IL6) and the lowest level of cellular antioxidant genes (SOD 1 and 2), while the perirenal adipose tissue had opposite profile. Significant activation of p38 MAPK pathway was indicated by increased phosphorylation of p38 in the subcutaneous adipose tissue of Lantang pigs. Collectively, the bacteria-derived LPS induced inflammation-associated oxidative stress indeed exists in adipose tissues of Lantang pig, and the differential expressions of inflammatory and antioxidant genes, to some extent, account for the uneven development of the adipose tissue within bodies.