九龙牦牛肉质性状测定及肌肉蛋白质双向电泳的初步分析

肉质性状是畜禽最主要的经济性状.为阐明九龙牦牛(Bos grunniens)肉质的特性,对不同年龄和性别的九龙牦牛(n=107)肉的部分性状进行了测定.结果表明,0.5岁犊牦牛背最长肌的蛋白质、肌内脂肪(IMF)和肌红蛋白(Mb)含量、剪切力等均显著低于成年牦牛,而这些指标在成年公牦牛与成年母牦牛之间差异不大.不同年龄成年九龙牦牛背最长肌IMF含量接近,提示其IMF沉积受年龄影响相对较小.另外,牦牛背最长肌剪切力存在较大的个体间差异.与成年黄牛相比,牦牛背最长肌IMP含量低,蛋白质含量高,熟化后p H下降幅度小.本研究还建立了九龙牦牛肌肉双向电泳方法,为阐明肌肉差异表达蛋白提供了方法.九龙牦牛肉的蛋白质、IMF和Mb含量以及剪切力等与黄牛有明显差异.

Analysis of meat traits of Jiulong yak and primary study of muscle proteins by two-dimensional electrophoresis

Meat trait is the major economic trait of livestock and poultry. To elucidate the meat trait characteristics of Jiulong yaks (Bos grunniens), this study analyzed partial parameters of meat samples from Jiulong yaks (n=107) of different ages and genders. The contents of protein, intramuscular fat (IMF), myoglobin (Mb), and shear force of longissimus dorsi of 0.5 year-old yaks were significantly lower than those of adult yaks, although those parameters were similar between adult male yaks and female yaks. IMF contents of longissimus dorsi were similar among adult Jiulong yaks of different ages, suggesting that their IMF deposition was less affected by ages. In addition, shear force of yak longissimus dorsi differed among individuals. Compared with adult yellow cattle, yak longissimus dorsi showed lower IMP content and higher protein content, and less pH decrease after ripening. This research also developed a method of two-dimensional electrophoresis of Jiulong yak muscle proteins, which may help to elucidate differential expressed proteins of muscle tissue. Jiulong yaks showed differences compared with yellow cattle in their protein, IMF and Mb contents, as well as shear force of meat.