Study On The Relationship Of Muscle Fiber Histochemical Characteristics,Glycolytic Potential And Meat Quality In Bamei Sheep

To investigate the relationship of the muscle fiber characteristics,glycolytic potential and meat quality of Bamei lamb, longissimus dorsi (LD), biceps femoris (BF), triceps brachii (TB) and supraspinatus(SS) muscles were obtained from lambs and were comparatively analyzed for improve the meat quality. All lambs were divided into four weight groups (A,30-40kg; B,40-50kg; C,50-60kg). The results showed that,A decrease in the compositions of type I and IIA fibers and an increase in the composition of type IIB fibers were observed in four anatomical locations with increasing weight. The cross-sectional area and diameter of muscle type fibers were found to increase with increasing weight. The growth of type IIB was mainly in earily stage within the scope of the slaughter weight. Within the weight from40kg to60kg, the growth of muscle fiber was not obvious.In four anatomical locations type IIB fiber was the main muscle fiber. The compositions of type I was was significantly lower in longissimus dorsi than others (p<0.05). The number and area percentage of type IIA in supraspinatus(SS) were higher than others (p<0.05). The oxidative muscle fibers number and area proportion of longissimus dorsi were the lowest, but were the highest in triceps brachii (TB) and supraspinatus(SS). On the contrary, the composition of type IIB fibe was higher in longissimus dorsi than other three anatomical locations, and was lower in supraspinatus(SS) than other three anatomical locations. What’s more,the change of muscle fiber size was that type IIB fiber was higher than other.In four anatomical locations, the glycolytic potential in weight from40kg to50kg was higher than other groups. Within the slaughter weight in the group from40kg to50kg,the glycolytic potential of Bamei lamb was significantly higher in longissimus dorsi than others and was significantly lower in triceps brachii (TB) than others.The slaughter weight showed a significant positive correlation with fiber number percentage and the area of type IIB, but was negatively correlated with type I and IIA. Fiber number percentage and the area percentage of IIA was positively correlated with glycolytic potential. The pH24showed a significant positive correlation with fiber number percentage and the area of type IIA, and was nagatively correlated with type IIB. The WBSF was negatively correlated with the number percetage and diameter and cross-sectional area of type IIA. The diameter of type IIA showed a significant positive correlation with the rate of cooked meat.In conclusion, a decrease in the compositions of type I and IIA fibers and an increase in the composition of type IIB fibers were observed in four anatomical locations with increasing weight. The cross-sectional area and diameter of muscle type fibers were found to increase with increasing weight.In four anatomical locations type IIB fiber was the main muscle fiber. The glycolytic potential in weight from40kg to50kg Was higher than other groups. The liveweight was negatively correlated with the compositions of type I and IIA fibers. The meat quality was negatively correlated with the compositions of type IIA.