关键词: 乳腺炎, 体细胞评分, 中国荷斯坦牛, 遗传多态性, 乳铁蛋白基因5′侧翼区

Abstract: Bovine lactoferrin (LF) is a multifunctional glycoprotein found in milk, which acts mainly as a defense factor in the mammary gland. Polymorphism has been found in the bovine LF gene. However, there is no report on genetic poly-morphism of LF gene and its associations with mastitis in dairy cattle. In this study, the promoter fragment of LF gene con-taining -926(G/A), -915(T/G), -478(/G), and +72(T/C) mutations were genotyped by the PCR-RFLP and CRS-PCR method. Two hundred and sixty-eight Chinese Holstein cows were screened. Least square linear model (LSM) analysis was applied to evaluate the associations of LF gene with somatic cell score (SCS). The results indicated that the SCS was sig-nificantly affected by -478(/G) and +72(T/C), but not by the other two loci (P >0.05). The SCS of cow with genotype AB in +72(T/C) position was significantly lower than that of genotype AA (P<0.01) or AB (P<0.05). In position -478(/G), the cow with genotype CC showed significantly lower SCS in contrast to cow with genotype CD and DD (P < 0.01). In conclusion, genotype AB in position +72(T/C) and genotype CC in position -478(/G) of LF gene were advantageous genotype, which can be used as candidate markers for mastitis resistance selection in dairy cattle.