中文摘要：

研究比较我国不同品种牛肌肉纤维特征,为高档牛肉生产和品种培育提供技术参数。运用肌肉组织冰冻切片、琥珀酸脱氢酶染色法（SDH）研究6个品种肉牛（利木赞牛、皮埃蒙特牛、中国西门塔尔牛、鲁西牛、秦川牛和晋南牛）的背最长肌、腰大肌、股二头肌的肌纤维类型、肌纤维直径和肌纤维密度等特征。结果表明：1）鲁西牛和利木赞牛背最长肌的红肌纤维（R型）比例分别为32.7%和29.5%,显著高于其他4个品种（P〈0.05）;晋南牛腰大肌和鲁西牛股二头肌的R型纤维比例最高为42.7%和48.7%;2）秦川牛背最长肌中的3种类型肌纤维直径值分别为60.009、61.109和67.800μm均显著大于另外5个品种（P〈0.05）,秦川牛和晋南牛的腰大肌和股二头肌的红肌纤维（R型）和中间型纤维（I型）的肌纤维直径显著大于其他4个品种（P〈0.05）;3）皮埃蒙特牛和利木赞牛腰大肌的红肌纤维（R型）密度分别为216.667和189.583根/mm2,白肌纤维（W型）密度分别为200.926和261.11根/mm2显著大于其他品种（P〈0.05）;鲁西牛的背最长肌和股二头肌的R型肌纤维密度大于其他品种;4）每一品种牛不同部位肌肉组织中不同肌纤维类型的比例在6个品种中没有明显的规律性,而肌纤维直径,除晋南牛股二头肌的肌纤维直径最大,其他5个品种牛均是背最长肌的肌纤维（3种）直径显著大于腰大肌（P〈0.05）;除晋南牛外,其余5个品种牛腰大肌的肌纤维密度显著大于背最长肌和股二头肌的肌纤维密度（P〈0.05）。不同品种肉牛,同一部位的肌纤维类型比例、肌纤维直径和肌纤维密度是存在差异的;除晋南牛外,另外5个品种肉牛均是腰大肌部位的肌纤维密度最大、背最长肌肌纤维直径大于腰大肌肌纤维直径,而晋南牛有其自身的特点。

英文摘要：

The objective of this study was to investigate the characteristics of different breeds of cattle in China and provide technical parameters for the production of superior quality beef and breed selection.Fiber characteristics of longissimus dorsi,musculi psoas major and biceps femoris in six Chinese breeds of cattle were studied using cryostat section and enzyme succinate dehydrogenase（SDH） staining.1） The percentage of red muscle（R type） of longissimus dorsi in Luxi cattle and Limousine（32.7% and 29.5%） is significantly higher than that of others breeds（P0.05）;While,the percentage of R muscle fiber types of musculi psoas major and biceps femoris is the highest in Jinnan cattle and Luxi cattle（42.7% and 48.7% respectively）.2） The diameter of all the three muscle fiber types of longissimus dorsi（60.009,61.109,67.800 μm） in Qinchuan is significantly thicker than that of the other breeds cattle（P0.05）;The diameter of Red and Intermediate types of muscle fiber of musculi psoas major and biceps femoris in Qinchuan and Jinnan cattle is significantly thicker than that in other four breeds of cattle（P0.05）.3） The density of all the R（216.667 and 189.583 num/mm2） and W（200.926 and 261.11 num/mm2） muscle fiber types of the musculi psoas major in Piemontese and Limousine is significantly higher than the one in other breeds of cattle（P0.05）;The density of the R muscle fiber types of the longissimus dorsi and biceps femoris in Luxi cattle is higher than that in other breeds of cattle.4） For the same breed,the percentage of the three muscle fiber type in different part of the body in six breeds of cattle has no obvious consistency.The diameter of longissimus dorsi muscle fiber is significantly thicker than that of musculi psoas major in the five breeds of cattle（P0.05）,except for Jinnan breed whose biceps femoris has the thickest diameter of muscle fiber.Also,the density of muscle fiber of musculi psoas major in the other five breeds is significantly higher than that of l