[Effects of several microsatellite DNA loci on milk production in dairy cattle]

The amplified fragment length polymorphisms of 7 microsatellite DNA loci linked with weaver gene according to the comparative map of mouse and cattle were detected in 178 Holstein cattle. Results showed that there were 4 and 6 alleles at BM6438 and BMS2321 loci respectively. Two alleles at BMS4020 locus and 5 alleles at BMS711 locus were detected. Two alleles at INRA117, 3 alleles at CA095 and 3 alleles at TGLA116 locus were found. Among these 7 microsatellite loci, BM6438, BMS711 and BMS2321 were high polymorphic loci, and PIC(polymorphism information content) was 0.58, 0.67 and 0.67 respectively. PIC of the moderate polymorphic locus TGLA116 was 0.45. BMS4020, INRA117 and CA095 were low polymorphic loci with PIC of 0.06, 0.05 and 0.05 respectively. Effects of BM6438, BMS2321, BMS711 and TGLA116 on milk production traits were analyzed with PROC GLM of SAS. Results showed that the four loci had no significant effect on milk yield of Holstein cattle, effect of BM6438 and BMS711 on milk composition was not significant either(P > 0.05). BMS2321 had a significant effect on protein yield and protein percentage(P < 0.01). The effect of TGLA116 on protein yield and protein percentage reached a significant level at P < 0.05.