营养水平对杂交肉牛FABP3基因表达及IMF的影响

Effect of different total mixed ration on FABP3 mRNA expression and intramuscular fat in crossbred cattle

为研究营养水平对杂交肉牛心脏型脂肪酸结合蛋白(FABP3)基因表达及肌内脂肪含量(IMF)的影响,以西门塔尔、利木赞和夏洛莱杂交肉牛为研究对象,利用实时荧光定量PCR技术,分别测定高、中、低营养水平的3种杂交肉牛背部脂肪中FABP3mRNA表达水平,并测定其背最长肌IMF。结果:(1)高营养组中夏洛莱牛IMF高于同营养组其他2种肉牛,其背部脂肪中FABP3mRNA水平也显著高于另外2种杂交肉牛(P<0.01);中营养组中西门塔尔和利木赞牛IMF均高于同营养组的夏洛莱牛,但FABP3mRNA的水平无显著差异(P>0.05);低营养组中夏洛莱牛IMF和FABP3mRNA水平均显著低于另外2种肉牛(P<0.01);(2)夏洛莱杂交肉牛背部脂肪中FABP3mRNA水平与IMF具有显著的相关性(P<0.05),而西门塔尔和利木赞牛中FABP3mRNA水平与IMF无显著相关性(P>0.05)。该结果表明提高营养水平影响FABP3mRNA表达并在一定程度上影响IMF,但影响显著与否存在品种差异,在肉牛育种和牛肉生产中应当同时考虑营养因素和遗传因素。

The experimental cattles were given low,medium and high TMR,FABP3 mRNA expression level was detected in back fat by real-time PCR and IMF content in lonfissimus dorsal muscle was determined.Results：（1） IMF content was highest in Charolais crossbred cattle given high TMR,and FABP3 mRNA expression level was also significantly highest in Charolais crossbred cattle（P0.01）.IMF content of Simmental and Limousin crossbred cattle were higher than Charolais,while there was no difference between three crossbred cattle given medium TMR（P0.05）.IMF content and FABP3 mRNA expression level of Charolais crossbred cattle were lower than other cattle given low TMR（P0.01）.（2） In Charolais crossbred cattle,the FABP3 mRNA expression level was significantly correlated（P0.05） with IMF content,but there was no significant relation between FABP3 mRNA expression level and IMF content（P0.05）.Conclusion：improving nutritional levels could influence FABP3 mRNA expression and IMF content partly.The results suggested that nutritional level and genetic factor should be considered in cattle breeding and beef production.