Study On Muscle Histological And Physicochemical Characteristices Of Sunit Sheep

The histological characteristics (the number proportion, the area proportion, diameter, cross-sectional area) and physicochemical characteristics (water content, fat content, pH1value, pH24value, meat color score, shear force and water loss rate) were measured to study the correlation between the two properties of Sunit sheep systematically. The variances in these characteristics of different anatomical locations (musculus longissimus dorsi, musculus biceps femoris, musculus triecps brachii), different ages (5months,6months and8months), and different breeds (Sunit sheep, Bamei lamb, Small fat-tail sheep) were tested to reveal the meat quality properties of Sunit sheep. The results showed that type II b fiber was the main type in muscles, and its diameter and cross-sectional area were greater than type I and type Ⅱa. In LD, the content of I, Ⅱa muscle fiber was the least, the BF followed, TB was the most. Type II b was opposite. There was no difference in the fiber diameter and cross-sectional area of type I fibers among muscles. However, the fiber diameter, cross-sectional area of type Ⅱa fibers and type Ⅱb fibers were significantly different among muscles (p<0.05). The content of type I was reduced with increasing age in three parts. The content of type Ⅱa increased with the rise of months in the LD, but reduced with the increasing of months in BF, TB. There were no significant changes in the content of type Ⅱb of LD with different months of age, but the content increased with the rising of months of age in BF and TB. Muscle fiber diameter and cross-sectional area increased with the increasing age. The muscle fiber diameter and cross-sectional area of Sunit sheep were the thinnest among different breeds(p<0.05). Thers was no significant difference(p>0.05) of moisture content and pH value in different parts, ages and breeds. Crude fat content, water loss rate were significantly different (p<0.05) in disparate parts, months of age and breeds.There were no significant differences in the shear force of parts and breeds, but it changed a lot as the different months of age (p<0.05). The differences in the color of different months of age were remarkable (p<0.05), but not significant in parts and breeds. The correlation between muscle fiber characteristics and the shear force was distinct in the BF(p<0.01), not significant in the LD and TB. The correlation between muscle fiber characteristics and the content of crude fat was significant in the TB(p<0.05), not distinct in the LD and BF. The degrees of correlation between muscle fiber characteristics and other physicochemical characteristics were different. The correlations between muscle fiber characteristics and other physicochemical characteristics were different in disparate anatomical locations of Sunit sheep.