Mastitis and Reproductive Complication in Dairy Cattle: A Comprehensive Review

Abstract

Mastitis and reproductive complications in cattle are among the most challenging disease conditions in dairy cattle farming. Traditionally, mastitis is associated with a decrease in milk production and quality, an increase in veterinary costs, culling rate, and susceptibility to other diseases. However, in recent times, the detrimental effect of mastitis on reproduction and fertility has gained everyone’s attention. Most of the research findings relating mastitis to reproduction are derived from a retrospective approach rather than controlled clinical studies. There is a constraint in understanding the detailed relationship between mastitis and reproduction due to the individual complexity of both conditions. Available information indicates that mastitis leads to decreased pregnancy rate, an aberration in the estrus cycle, early embryonic mortality or abortions, prolonged days open, a higher number of services per conception, and decreased conception rate. Decreased reproductive performance in mastitis-affected cows could be due to hyperthermia, impaired embryonic development and oocyte maturation, physiological alteration in the uterus, and disturbances of the hypothalamic-pituitary-ovarian axis. Increased cytokines associated with intramammary infection act as a key modulator of reproductive function. Although mastitis harms reproductive performance, studies show that the effect varies with the type, timing, incidence, the degree of elevation of somatic cell count (SCC), and the type of pathogen involved. The present review furnishes the available information on the effect of mastitis on reproduction and attempts to explain the possible mechanisms by which mastitis influences reproductive performance in dairy animals. Further research and studies are required to comprehend the relation between mastitis and reproductive performance in dairy animals.