Dynamics of postpartum endometrial cytology and bacteriology and their relationship to fertility in dairy cows

Abstract

Endometrial samples were obtained from 56 consecutively calving dairy cows examined for endometrial cytology and for aerobic and anaerobic bacterial growth. Changes over time, correlations between different cell types and between cell and bacterial populations and with fertility measures were calculated. The proportion of neutrophils in cytologic preparations decreased with time postpartum. Other cell types did not change significantly with time. The proportion of neutrophils early (Day 0 and 7) postpartum was negatively correlated with neutrophil proportion at 5 or 7 weeks postpartum and positively correlated with fertility. Cows with high proportion of neutrophils at 7 days postpartum (>40%) were significantly more likely to become pregnant than those with lower proportions of neutrophils. Escherichia coli were the bacteria most frequently isolated at 0 or 7 days postpartum but were uncommon after that. Trueperella pyogenes were most prevalent at 3 weeks postpartum and were more likely to infect cows that had previously been infected with E coli. The presence of T pyogenes at 3 weeks postpartum increased the risk of concomitant or later infection with gram-negative anaerobes. The presence of T pyogenes at 3 weeks postpartum significantly reduced the risk of pregnancy at 150 days in milk. The presence of alpha-hemolytic Streptoccus spp. at 7 days postpartum was associated with improved reproductive performance. The proportion of neutrophils at 5 and 7 weeks postpartum was related to concomitant bacterial infection. These findings suggest that rapid mobilization of neutrophils to the postpartum uterus is a beneficial response for uterine health in dairy cows.

Quantification of the uterine involution and dimensions, hormonal response and reproductive performance of pyometric and healthy dairy cows treated with Dinoprost

“…Interestingly, elevated systemic inflammation (which was characterized by higher concentrations of Haptoglobin) during the early postpartum period was negatively associated with the ovulatory status of the first dominant follicle and reproductive performance of cows. In addition, contamination of uterus with Trueperella pyogenes at 3 weeks postpartum significantly reduced the risk of pregnancy at 150 days in milk (Gilbert and Santos, 2016). Results of the present study showed that Dinoprost injection increased pregnancy rate in pyometric cows which is consistent with previous studies (Mortimer et al, 1984;El-Tahawy et al, 2011).…”

Uterine and systemic inflammation influences ovarian follicular function in postpartum dairy cows

“…Cows that have stronger initial recruitment of inflammatory cells into the uterus have been shown to have a faster resolution of uterine inflammation postpartum [23]. On the other hand, elevated uterine fluid pH was associated with prolonged uterine inflammation when sampled between 40–60 days postpartum [37].…”

“…Most cows have some bacteria in the uterus early postpartum, but the type of bacteria present may be important. Some bacterial species have been negatively associated with fertility such as Escherichia coli , Trueperella pyogenes , Fusobacterium necrophorum , and Prevotella melaninogenica while the presence of alpha-hemolytic streoptococcus early postpartum appears beneficial [8,23,24]. Intrauterine inflammation is usually diagnosed by cytological evaluation of cells in uterine samples [25–27].…”

“…Intrauterine inflammation is usually diagnosed by cytological evaluation of cells in uterine samples [25–27]. A higher proportion of polymorphonuclear leukocytes (PMN) in uterine samples associated with robust initial recruitment of PMN hastens resolution of uterine inflammation postpartum [23]. Cows with intrauterine inflammation persisting beyond 35 days after calving are considered to have endometritis [28].…”

Symposium review: Mechanisms of disruption of fertility by infectious diseases of the reproductive tract

“…Common diseases of dairy cows include retained fetal membranes, metritis, and endometritis (as well as cervicitis), mastitis, lameness and abomasal displacement, clinical hypocalcemia, and ketosis. All of these diseases occur most frequently in the early part of lactation and thus in the period preceding and immediately following insemination (Foditsch et al, 2016;Gilbert and Santos, 2016;Neves et al, 2018). Interestingly, all of these conditions detrimentally affect reproductive performance, whether they are infectious (metritis, endometritis, mastitis, and some cases of lameness) or noninfectious (lameness and abomasal displacement, hypocalcemia, and ketosis).…”