Isolation and Identification of Uterine Microorganisms in Postpartum Dairy Cows

Uterine infection is a major problem in reproductive management and inefficient estrous detection. The bovine uterus is sterile before calving and the cervix provides a barrier against intrauterine invasion by pathogens during gestation1. Following calving, the uterus may become infected due to presence of infectious or non-specific microorganisms. Several bacterial, protozoan, viral and mycoplasmal infections are common in postpartum period. The most common and economically important bacteria for uterine infection are Actinomyces spp, Escherichia coli, Fusobacterium spp, Pasteurella spp, Pseudomonas spp, and Staphylococcus spp2. Cows with uterine infection in the postpartum period generally have lower conception rates at subsequent breeding. A high percentage of cows have bacteria present in the uterus during the first two weeks after calving may be considered as infected. However, by two months post-calving, the prevalence of uterine infection decline to less than 10 percent. Even though, pathogenic bacteria persist in some cows causing uterine disease by preventing physiological uterine involution resulting in sub-fertility in individual cows or even in the whole herds3. Bovine genital infections, either specific or non-specific in nature, account for large number of pregnancy failure in cows4. Generally, nonspecific infection of the genitalia is considered to be the main cause of repeated conception failure5,6. Bacterial infection is the most important among the various causes of endometeritis7. Such a condition may cause cervicitis or endometritis of various degrees, which may lead to embryonic death and repeat breeding problems8. These infections affect fertility by altering the uterine environment resulting in sperm transport impairment, sperm death and hostile environment to subsequent development and maintenance of the conceptus leading to their death9. Incidence of uterine infection in cattle decreases with the increasing of the postpartum period, ranging from 90% in 25 days of calving to postpartum to 9% in 46-60 days of postpartum period10.