ABSTRACT. This study analyzed the effect of muscle-fiber type composition on glycogenin-1 (GYG) gene expression and its impact on pH. The longissimus dorsi (LD) muscle contains more type IIB fibers (75.10%) than does the psoas major (PM) muscle (41.58%), while the PM has more type I (3.65 vs 0.94%), type IIA (34.15 vs 10.63%), and type IIX (20.62 vs 13.33%) fibers. Compared with PM, glycolytic potential (GP), pH 45 min , and DpH from 45 min to 24 h post-mortem were all relatively higher in LD. Glycogen metabolites (lactate and GP) were negatively correlated with pH 24 h and positively correlated with DpH. Expression of GYG was generally higher in LD. GYG expression was positively correlated with glycogen metabolite (lactate and GP) content and DpH, and was negatively correlated with pH 24 h . These data confirm that the muscle-fiber type and GP have significant effects on ultimate pH and pH decline, and suggest that expression of GYG in muscles is related to the metabolism of glycogen and may impact GP, ΔpH, and ultimate pH. High expression of GYG was associated with a high glycogen content, large pH decline, and low ultimate pH in muscles post-mortem.

ABSTRACT. The aim of this study was to analyze the results of two crossing systems between wild boars and different domesticated pig breeds. Hybrid wild boars were produced by crossing captured wild boars with Meishan pigs and LY sows according to the traditional production system. The resultant commercial hybrids were black and white in coat color, respectively. Significant differences were found in the carcass and meat quality traits and nutritional values between these two hybrid wild boars. Compared with the white hybrid wild boars, at the age of 300 days, the body weight of black hybrid wild boars was 9.41 kg lower, while percent lean was 2.51% less and percent fat 2.45% higher (P < 0.05). The black hybrid wild boars had higher pH 2 (6.17 vs 6.09) and intramuscular fat (3.34 vs 2.52%), lower drip loss (2.21 vs 2.68%) and shear force (44.00 vs 52.23) (P < 0.05), and more unsaturated fatty acids and essential amino acids (P < 0.05). In conclusion, cross breeding was shown to be an effective method to improve the overall production performance of wild boars, but crossing 2609 Performance of hybrid wild boars with different crossing systems ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (1): 2608-2616 (2015 with different dam line breeds caused different responses. Compared with the white hybrid wild boars, the black hybrid wild boars had worse growth rate and carcass traits, but better meat quality traits and nutritional values.