A REVIEW ON BOVINE MASTITIS WITH SPECIAL FOCUS ON CD4 AS A POTENTIAL CANDIDATE GENE FOR MASTITIS RESISTANCE - A REVIEW

Mastitis is an inflammation of the mammary gland, caused by the invasion and duplication of Escherichia coli (E. coli), Staphylococcus uberis (S. uberis) and Staphylococcus aureus (S. aureus) and a wide variety of other microorganisms through teat or damaged nipple, decreasing potential milk production in the affected quarter of mammary gland. Economic, animal productivity, international trade and animal welfare issues associated with mastitis play an important role in the agricultural industry. Therefore, worldwide dairy cattle breeding programs are trying to breed cows with improved resistance to mastitis. Mastitis cannot be eliminated but can be reduced to a low level. This can be achieved by breeding strategies, reducing the exposure to pathogen and increasing the resistance to intramammary infection. Numerous therapeutic, prophylactic and management techniques are used to control and reduce the mastitis. However, a widely proposed strategy is marker assisted selection using candidate gene approach which is based on improving the host genetics. One of them is cluster of differentiation 4 (CD4) gene, which is a glycoprotein located on receptors of immune cells. CD4 exhibits an essential role in a variety of inflammation related conditions in many species. Therefore, CD4 as a candidate gene for resistance to mastitis has received considerable attention. The review is based on a study of CD4 in association with improving resistance to mastitis and it may he helpful in formulating breeding programmes and marker assisted selection to lower the mastitis.