Impact of bovine lipocalin-2 haplotype on milk composition, somatic cell score and incidence of mastitis in Polish Holstein-Friesian cattle

Abstract

Lipocalin-2 (LCN2) is a secreted protein, produced e.g. by neutrophils – the main group of cells involved in inflammatory conditions caused by pathogenic bacteria. So far, no studies have been carried out on the genetic variability of the LCN2 gene in cattle in terms of immunity/susceptibility to mastitis in cows. This study concerns the analysis of polymorphisms within the LCN2 gene in cattle and their impact on the production traits and the incidence of mastitis in Polish Holstein-Friesian cows. Using the PCR-RFLP method, two polymorphisms – g.98784892C > T and g.98784893T > G – were identified in intron 5 of the LCN2 gene, which represent two haplotypes (CT and TG, respectively). The CT haplotype was shown to have a significant impact on the average somatic cell score of milk, however, the CT and TG haplotypes were found to have no impact on the milk yield, protein, fat and lactose levels, or the incidence of mastitis in cows. An analysis of polymorphisms in the bovine LCN2 gene could be employed in future to support selection in dairy cattle breeding programmes focused towards the somatic cell count in milk, and the LCN2 gene itself could become a molecular marker of cows’ immunity to mastitis.

Keywords

• lipocaline-2
• polymorphism
• gene
• somatic cell score
• mastitis