Lactoferrin gene promoter variants and their association with clinical and subclinical mastitis in indigenous and crossbred cattle.

Lactoferrin (Lf) gene promoter was screened for the presence of single nucleotide polymphism in indigenous and crossbred cattle from North India and to evaluate its association with Mastitis. Study revealed the presence of genetic variation in regulatory region of bovine Lactoferrin gene using PCR-RFLP technique. Three genotypes namely GG, GH and HH were identified. A single nucleotide change, from guanine to adenine at 25th position was found to be significantly associated (p<0.05) with clinical mastitis in indigenous Sahiwal and crossbred Karan Fries cattle maintained at organised herd of National Dairy Research Institute, Karnal. A non-significant association was observed between subclinical mastitis, somatic cell score (SCS), and GG genotype in Karan Fries cattle, however, a lower SCS was observed in animals having GG genotype. Overall a lower incidence of clinical mastitis was recorded in those animals having GG genotype of Lf in Sahiwal and Karan Fries (KF) cattle. The SNP identified in the promoter region may effect expression lactoferrin protein, which may lead to different levels of antibacterial and anti-inflammatory activity of Lf gene. Results from this study indicated the probable role played by Lactoferrin promoter to serve as candidate gene for mastitis susceptibility among indigenous and crossbred milch cattle.