中文摘要：

以6月龄苏尼特羊（6只）的股二头肌为实验材料,同时以同月龄的巴美肉羊（10只）、小尾寒羊（10只）为对照,用ATP酶（ATPase）组织化学法染色,对比其肌纤维密度、不同类型肌纤维的数量比例和面积比例、单根肌纤维直径及肌纤维横截面积,并分析了苏尼特羊肌肉组织学特性与肉品质之间的相关关系,揭示了苏尼特羊的肉质特性.结果表明：3个品种的股二头肌中ⅡB肌纤维比例均为最多;苏尼特羊Ⅰ型肌纤维的数量比例、面积比例和肌纤维直径均显著小于巴美肉羊（P＜0.05）,横截面积显著小于巴美肉羊和小尾寒羊（P＜0.05）;苏尼特羊ⅡA型肌纤维面积比例显著小于巴美肉羊和小尾寒羊（P＜0.05）;ⅡB型肌纤维横截面积显著小于小尾寒羊（P＜0.05）.苏尼特羊股二头肌的肌纤维密度与粗脂肪含量呈显著正相关,与剪切力呈负相关,ⅡB型肌纤维数量比例与极限pH值显著负相关（P＜0.05）.

英文摘要：

The objective of this study was to characterize the profile of muscle fibres from the same muscle （bicepsfemoris,BF） among different breeds （Sunit sheep,Bamei sheep and Small Tail Han sheep） by histochemical analysis.Six Sunit sheep,ten Bamei sheep and ten Small Tail Han sheep were slaughtered at 6 months of age.Ovine skeletal muscle fibres were classified using the myosin ATPase staining technique with an acid preincubation solution （pH 4.6）,into three types （Ⅰ,Ⅱ A and ⅡB）.The fiber number,area percentage,diameter and cross-sectional area of each fiber type were studied.The relationship between fiber types and meat quality of Sunit sheep traits was also examined.The results showed that fiber number percentage of type ⅡB was the most common in BF muscle of three breeds.The fiber number,area percentages and diameter of type Ⅰ in Sunit sheep were significantly lower than those in Bamei sheep （P ＜ 0.05）.The cross-sectional area of type Ⅰ and the fiber area percentage of type Ⅱ A and were significantly lower than those in Bamei sheep and Small Tall Han sheep （P ＜ 0.05）.The cross-sectional area of type ⅡB was significantly lower than that in Small Tail Han sheep （P ＜ 0.05）.For Sunit sheep,fiber density in BF muscle had a positive correlation with fat content （P ＜ 0.05） and a negative correlation with WBSF.Fiber number percentage of type Ⅱ B had a negative correlation with ultimate pH （P ＜ 0.05）.