Genetic Association of Bovine TNF-α Gene Polymorphism with Clinical and Sub-clinical Mastitis in Sahiwal Cows

One major problem of dairy cattle industry is the high prevalence of mammary gland infection. Despite significant technological developments in animal husbandry, udder infection is still widespread; particularly in large herds that causes high production losses to the dairy industry of Pakistan. Identification of molecular marker sequences that are directly related to immunity against mastitis might be helpful for animal selection trait and prevention of this disease. The aim of the present study was to assess the effect of polymorphism in bovine tumor necrosis factor alpha (TNF-alpha) gene on immune function and its role in mastitis susceptibility in Pakistani Sahiwal cows. In this study, a total of 150 Sahiwal cows were selected suffering from clinical (n=50), subclinical (n=50) mastitis along with non-mastitic (n=50) cows from different dairy farms of Punjab. TNF-alpha gene was amplified with specific primer and sequenced to get the full-length sequence of this gene. A total of nine changes including transition (n=6) and transversion (n=3) were found at the different position of this gene. Due to these changes, the amino acid is changed that leads to significant change in the folding of 3D protein structure of clinical sample, while in subclinical samples, showing the same variation in overall 3D protein structure analysis of TNF-alpha gene. The association between polymorphism identified within the TNF-alpha gene with mastitis reported in this study revealed that SNPs has potential to serve as a molecular marker for screening of mastitis resistant and susceptible Sahiwal cows.