Cytological endometritis in dairy cows: diagnostic threshold, risk factors, and impact on reproductive performance

Abstract

We determined the threshold proportion of polymorphonuclear leukocytes (PMNs) for a diagnosis of cytological endometritis (CEM), the risk factors for this condition, and its impact on reproductive performance in dairy cows. Uterine cytology was performed on 407 Holstein cows 4 weeks postpartum to determine the proportions of endometrial cells and PMNs. A receiver operator characteristics curve was used to determine the threshold above which the PMN proportion affected the likelihood of cows conceiving by 200 days postpartum. The optimal threshold was ≥ 14% PMN (sensitivity, 31.3%; specificity, 81.7%; p < 0.05). The farm identity, retained placenta (odds ratio [OR] = 1.87), and septicemic metritis (OR = 3.07) were risk factors for CEM (p < 0.05). Cows with CEM were less likely to resume cyclicity (OR = 0.58) and to conceive by 200 days postpartum (hazard ratio = 0.58). Cows with CEM tended (p < 0.1) to be less likely to become pregnant after their first insemination (OR = 0.65) and to require a greater number of inseminations per conception (2.3 vs. 2.2). In conclusion, a PMN threshold of 14% defined the presence of CEM at 4 weeks postpartum. The farm, retained placenta, and septicemic metritis were risk factors for CEM, which reduces subsequent reproductive performance.

Cytological endometritis in dairy cows: a preliminary study

“…The decreases in reproductive performance (low probability of conception following the first insemination, more AIs required per conception, and lower chance of conception by 200 days postpartum) observed in cows with CEM in the present study are comparable to the results of several previous studies (Kasimanickam et al, 2004;Gilbert et al, 2005;Barlund et al, 2008;Ahmadi et al, 2016;Lee et al, 2018).…”

“…In the current investigation, although not significant, problem cows had higher incidence of CE than did their normal herd-mates. Similarly, Lee et al (2018) mentioned that diseases like retained placenta, and septic metritis increase the incidence of CE due to creating and establishing favorable conditions for microbial growth inside the uterus. In our study, the low number of cows included in the study might have influenced the statistical significance.…”

Influence of endometritis on milk yield of zero-grazed dairy cows on smallholder farms in Rwanda

“…The threshold values of PMN for predicting SCLE positive case are 8% PMN for 21 to 33 DIM; 6% PMN for 34 to 47 DIM; and 4% PMN for 48 to 60 DIM. However, the PMN threshold for the overall period (21 to 62 DIM) is ≥5% when the applied method counts 300 cells per endometrial cytology slide ( Madoz et al., 2013 ; Melcher et al., 2014 ; Okawa et al., 2017 ; Chan Lee et al., 2018 ).…”

Nutritional condition in the dry period is related to the incidence of postpartum subclinical endometritis in dairy cattle

“…The prepared slides were assessed twice by two clinicians, one of whom collected the samples, and another did not, as in the study by Wagener et al [ 10 ]. We set 5% to 14% as the cut-off PMN% for defining the SCE; 5% PMN is considered adequate for diagnosing SCE at 21 to 62 DPP [ 9 , 10 ] while 14% PMN% is used as the CE threshold [ 11 ]. Cytological samples in PMN%<4, 5<PMN%<14, 15< PMN% were categorized as normal, SCE, and CE, respectively.…”

“…The percentage of polymorphonuclear (PMN) cells, calculated from the total number of the PMN and endometritis cells obtained by uterus lavage or cytobrush [ 8 ], has been usually used to define both, CE and SCE. To date, several definitions of endometritis have been postulated; 5% PMN is adequate as a diagnostic criterion for SCE at 21 to 56 DPP in some studies [ 9 , 10 ], while others stated that 14% PMN is a suitable threshold for diagnosing CE at 4 weeks after the delivery [ 11 ], or 18% PMN at 20 to 33 DPP is a better threshold for diagnosing CE [ 12 ]. Thus, the percentage of PMN is a particularly important indicator for improving SCE treatment.…”