RESUMEN
<p><b>OBJECTIVE</b>To study the effect of the polymorphism F279Y of the growth hormone receptor (GHR) gene on milk yield and composition in Chinese Holstein cattle.</p><p><b>METHODS</b>Hundred thirty two Chinese Holstein cattle were selected as study materials, according to DHI production performance method to get the data of milk yield and composition; PCR- SSCP and sequencing method were used to detect the genotypes; least square method was used to acquire correlation analysis.</p><p><b>RESULTS</b>Chinese Holstein cattle F279Y of GHR gene loci A and T allele frequency were 0.68 and 0.32, respectively, the experimental group significantly deviated from Hardy Weinberg equilibrium (P < 0.01); 305 d milk yield of AA genotype was significantly higher than AT type (P < 0.05), 305 d milk fat yield, 305 d milk protein yield and 305 d lactose of AT type had better trend than those of AA type in numeric; Therefore, allele A was dominant gene of high milk yield, allele T has positive effect on milk composition.</p><p><b>CONCLUSION</b>Mutation F279Y of GHR gene can be used as genetic markers in Chinese Holstein milk production traits of marker assisted selection (MAS) breeding.</p>