牛肉质性状在遗传育种中的研究进展

牛肉的内在品质,尤其是牛肉的嫩度,不仅与屠宰后肉的处理有关,而且还包括遗传、营养和饲养等影响活体的肌肉特性有关因素。不同的品种或同一品种不同的基因型肉品质的不同主要是通过结缔组织的特性、肌间脂肪的含量与组成分和肌纤维的特性。这些不同主要引起肉色和烹饪失水率的不同,还会引起风味和嫩度的不同。抑肌素基因的突变会引起肌肉的过度生长,促进糖分解肌肉纤维的代谢,还会导致胶原质和肌间脂肪含量的下降,从而影响肉的品质。肌间脂肪含量是高遗传变异的,嫩度是中等遗传变异的,风味和多汁性是低遗传变异的。决定结缔组织或肌纤维特性的一些关键基因的多态性都已经被鉴定,因为它们都与肉品质性状相关联。

Research Progress on Meat Quality Trait in the Genetic Breeding of Cattle

Intrinsic quality attributes of beef,especially its tenderness,depended not only on post-mortem factors,but also on muscle characteristics of live animals,includin genetic,nutritional and rearing factors.Different breeds or different genotypes of the same breed mainly differed by the characteristics of their connective tissue,content and composition of intramuscular fat and the characteristics of their muscle fibres.These differences induced mainly differences in meat colour,cooking losses,flavour and tenderness of beef.Mutation in the myostatin gene induced generalizedly hypertrophy of muscles,promoted a glycolytic muscle fibre metabolism,and also led to decrease collagen and intramuscular fat contents,then effected the meat characteristics.The genetic variability was quite high for intramuscular fat content,moderate for tenderness and low for flavour and juiciness.The identification of polymorphisms in some key genes which determined characteristics of connective tissue or of muscle fibres had been reported because of their association with beef quality traits.