Enhanced adipogenesis in Mashen pigs compared with Large White pigs

Abstract

Intramuscular fat (IMF) is critical pork meat quality; however, its content is relatively low in commercial pig breeds. The objective of this experiment was to investigate the difference in intramuscular adipogenesis between Mashen and Large White pigs. 12 male Mashen and Large White piglets (six in each breed) were used, and longissimus dorsi muscle was sampled for analysis. The results showed that back fat thickness (p < .01) and leaf fat weight (p < .05) were increased in Mashen pigs. Moreover, the IMF contents were greater in Mashen pigs (p < .01). With exception of sterol regulatory element-binding protein 1, mRNA expression of other adipogenic markers, including Zinc finger protein 423 (p < .05), platelet-derived growth factor receptor α (p < .05), CCAAT enhancer binding protein β (C/EBPβ, p < .05), C/EBPα (p < .05) and peroxisome proliferator-activated receptor γ (PPARγ, p < .01) were greater in Mashen pigs; consistently, protein abundance of both C/EBPα (p < .01) and PPARγ (p < .05) were also greater. Both mRNA expression of fatty acid synthase (FAS) (p < .01) and its activity (p < .05) were elevated in Mashen pigs, whereas no difference of acetyl-CoA carboxylase activity was observed. In addition, protein content of fatty-acid binding protein 4 (FABP4) was elevated in Mashen pigs. The malate dehydrogenase activity was greater (p < .05) and hormone-sensitive lipase activity was lower in Mashen pigs. In summary, IMF content was enhanced in Mashen pigs, which at least partly through enhancing intramuscular adipogenesis.