Mastitis and milk quality

Abstract

Mastitis is defined as an inflammation of the mammary gland. The inflammation is a response of the tissue to injury. The purposes of the inflammatory response are to destroy or neutralize the injurious agent and allow healing and return to normal function. A key component of inflammation is the influx of white blood cells or leukocytes which results in an increase in the somatic (body) cell count (SCC) of milk. Thus, the SCC is a common measure of mammary gland health and milk quality. Although inflammation can result from a variety of types of injury including infectious agents, physical trauma, or chemical irritants, mastitis in dairy cattle is generally the result of microorganisms which enter the mammary gland, multiply and produce toxins that cause injury to the mammary tissue. It is believed that mediators of inflammation may contribute to some of the pathophysiological responses in severe cases of mastitis. Bacteria are the most common causesof mastitis, but other types of organisms such as yeasts, mycoplasmas, and algae may occasionally infect the udder.