Structural Changes of the Gastrocnemius Muscle of Emasculated Native Taiwanese Chickens Using Succinate Dehydrogenase Localization

Abstract

The aim of this study was to compare the muscle fiber structural changes of the medial head and lateral head of the gastrocnemius muscle of intact cocks (Group 1), emasculated cocks with testicular tissue remaining (Group 2), emasculated cocks (Group 3), and intact hens (Group 4) of native Taiwanese DL2 chicken using results of succinate dehydrogenase localization studies. The results showed that the gastrocnemius muscle of each group of chickens contained Type-Ⅰ red muscle fibers, Type-ⅡA white muscle fibers and Type-ⅡB white muscle fibers. However, the percentages in each group varied. For the medial head of the gastrocnemius muscle, the ratio of white muscle fibers was higher than that of red muscle fibers. For the lateral head of the gastrocnemius muscle in the group 3, the ratio of white muscle fibers was higher than that of red muscle fibers. After comparing the muscle fiber diameters with the muscle fibers of each type in the medial head of the gastrocnemius muscle, there were no significant differences (P ＞ 0.01) among the four groups. But compared the muscle fiber diameters of the lateral head of the gastrocnemius muscle, type-Ⅰ red muscle fibers and type-ⅡA white muscle fiber of group 2 and group4 were significant differences (P ＜ 0.01). However merely the Type-ⅡB white muscle fiber of the group 2 were significant differences (P ＞ 0.01).