Comparison of Meat Quality and Blood Biochemical Indicators between Pale, Soft, and Exudative (PSE) and Normal Pork

The purpose of this study was to investigate the incidence of pale, soft and exudative (PSE) pork, compare the differences in carcass, meat quality and blood physiological indexes between pigs with PSE and normal meat, and explore the feasibility of using blood biochemical indexes as markers for identifying pigs producing PSE meat. A total of 392 Duroc ×Landrace × Yorkshire pigs were randomly selected and slaughtered according to the standard procedure. Their Longissimus dorsi muscle were collected to measure meat quality traits, and blood samples for routine and biochemical tests. The pigs were divided into PSE and normal pigs based on the meat quality traits of pH_{45 min}, pH_{24 h}, drip loss and water loss rate. Analysis of variance (ANOVA) and principal component analysis (PCA) were used to compare the differences between PSE and normal pigs, and explore the feasibility of distinguishing the two types of pigs by blood biochemical indexes. The results showed that: 1) the incidence of PSE pork was determined to be 10.2% based on two or more of the meat traits pH_{45 min} <5.9, pH_{24 h} < 5.6, drip loss > 5.0%, and water loss rate > 20.0%, the incidence of PSE pork at slaughter was 9.95% according to phenotype, and the consistency between them was 82.5%; 2) pH_{45 min} , pH_{24 h}, and intramuscular fat content (IMF) were significantly lower and L^*_{45 min}, L^*_{24 h}, drip loss, and water loss rate were significantly higher in PSE meat than in normal meat(P < 0.05); 3) the coefficients and significance of correlation among quality traits of PSE meat were higher than those of normal meat; 4) there were no significant difference in routine blood indexes between PSE and normal pork (P > 0.05); 5) the levels of aspartate aminotransferase (aspartate aminotransferase, AST), creatinine (CR), creatine kinase (CK), lactate dehydrogenase (LDH), urea, lactate (LAC) and glucose (GLU) in PSE pork were significantly higher than those in normal pork (P <0.05), but the blood biochemical indexes were not sufficient to distinguish PSE from normal pork.