The Difference Of Meat Quality, Muscle Energy Metabolism And MyHC MRNA Expression Between Erhualian And Pietrain Pigs At Transport Stress

In this study, Erhualian and Pietrain pigs at 20kg body weight were employed to investigate the effect of breed and transport stress on muscle quality, the lactic acid (LD) content and the activities of lactate dehydrogenase (LDH) and creatine kinase (CK), as well as the proportion of four muscle fiber types in longissimus dorsi.The pH_45min, pH_24h, water holding capacity (WHC), meat color of longissimus dorsi and W-B shear force of psoas were measured for estimating meat quality among different treatment groups of the two breeds. The pF_45min (P<0.01) and pH_24h (P<0.05) were significantly higher in Erhualian than Pietran pigs both in transport groups and control groups. No significant difference in meat color and WHC was observed in control groups but significant difference (P<0.05) in transport groups was seen between breeds, Erhualian exhibiting better meat quality traits than Pietran. There was no significant difference in tenderness between any groups, and Erhualian having large individual variations. Correlation analysis of meat quality parameters showed that pH_45min was correlated with pH_24h(r=0.549, P<.01), meat color(r=0.634, P<0.01), WHC(r=0.638, P<0.01); pH_24h was also correlated with meat color(r=0.364, P<0.05) and WHC(r=0.448, P<0.01); WHC was correlated with meat color (r=0.385, P<0.05) and W-B shear force (r=-0.561, P<0.01).The LD content and activities of CK and LDH of longissimus dorsi were measured for estimating the muscle energy metabolism capacity. There is no difference in LD content between breeds with same treatment and between groups of same genotype, but LD content negatively correlated with pH_45min (r=-0.455, P<0.01) and WHC (r=-0.587, P<0.01). The control group and transport group of Erhualian had higher LDH activity (P<0.05) than Pietran, and the activity of LDH have positive correlation with pH_45min(r= 0.410, P<0.05), pH_24h(r= 0.485, P<0.05) and WHC(r= 0.451, P<0.01). The CK activity of Erhualian were about twice higher (P<0.01) than Pietran. pH_45min (r= 0.741, P<0.01), pH_24h (r=0.573,...