关键词: 中国荷斯坦牛, 转铁蛋白基因, 多态性, 产奶性能, 单倍型

Abstract: 【Objective】The polymorphisms of transferrin gene and their correlation to milk performance and healthy traits in Chinese Holstein cattle were investigated, which may help to breed high milk yield and healthy cows.【Method】DNA sequencing, PCR-RFLP and CRS-PCR were applied to analyze the polymorphisms of transferrin gene in 576 Chinese Holstein cattle and its associations with production performance were investigated by SAS software.【Result】Three novel SNPs (g.-1748G＞A, g.13942T＞C and g.14037A＞G) in the 5′flanking region, exon 8 and intron 8 of Tf gene were found, respectively. The locus g.-1748G＞A was significantly associated with 305 d milk yield (P＜0.05). The locus g.13942T＞C was significantly associated with somatic cell score. The cows with genotype CC was significantly higher than TT and TC genotype (P＜0.05). At locus g.14037A＞G , the cows with genotype AA showed higher 305 d milk yield than those with genotypes AG (P＜0.05), with genotype AG showed higher protein rate than those with genotypes GG (P＜0.05). Eight haplotype and 19 haplotype combinations were found in 576 Chinese Holstein cattle. The cows with haplotype combinations H4H4 had the highest milk fat and milk protein percentage. The cows with haplotype combinations H2H5 had the highest 305 d milk yield and the cows with haplotype combinations H3H4 had the lowest somatic cell score.【Conclusion】The correlation was detected between different genotypes and haplotype combinations of Tf gene and milk yield, protein rate and somatic cell score, but there was no correlation between the polymorphisms and milk fat rate.

Key words: China Holstein, transferrin gene, polymorphism, milk performance, haplotype