Effects Of Genotypes,Castration Methods And Growth Hormone On Porcine Muscle Fiber Characteristics And Pork Quality

The objective of this study was to evaluate the effects of ractopamine supplementation, castration methods, two Pietrain pig genotypes and their interactions on the muscle fibre characteristics, glycolytic potential, sensory quality and meat quality of192pigs. The results showed that:1.50%Pietrain genotype decreased the subjective color score and marbling (P<0.05); increased shear force, glycolytic potential level and pork juciness, and increased of off flavor (P<0.01);50%Pietrain genotype had a tendency to reduce the proportion of muscle fiber type IIA, proportion of muscle fiber type IIB, the relative area of fiber IIB, tended to increased muscle fiber IIX and the relative area (P<0.10).2. Ractopamine significantly decreased muscle brightness value, the red value, whiteness and glycolytic potential (P<0.05); significantly increased IIX muscle fiber cross-sectional area and shear force; ractopamine extremely significantly decreased tenderness (P<0.001).3. Immunocastration increased glycolytic potential level and shear force value (P <0.05), and decreased marbling (P<0.05). Immunocastration had a tendency to increase the relative area of fibers type IIA (P<0.10); increased off flavor (P<0.01). When ractopamine didn’t add, immunocastration had juicer pork.In conclusion, Pietrain genotype had greatest impact on meat quality in three factors. Immunocastration and the use of Pietrain genotypes appears to be a viable alternative to the use of ractopamine, as it assures the production of lean carcasses without any major effect on pork quality.