Defining and diagnosing postpartum clinical endometritis and its impact on reproductive performance in dairy cows

Evaluation of endometrial echotexture and cervical cytology in cows during and after treatment of endometritis

OBJECTIVE

The aim of this study was to evaluate changes in the endometrium by using echotexture parameters during and after treatment of endometritis with intrauterine administration of an intrauterine antiseptic solution (Lotagen®, 3% metacresolsulphonic acid and formaldehyde) in cows which became pregnant after treatment.

MATERIAL AND METHODS

According to the severity of endometritis 21 cows were divided into three groups: E1 (slight, n = 7), E2 (moderate, n = 8), E3 (severe, n = 6). The control group (C, n = 11) consisted of cows without endometritis that did not receive an intrauterine medication. A software (Bs200 Pro®) was used to evaluate echotexture parameters Contrast (CON), Gradient (GR), Homogeneity (HOM), Mean Gray Level (MGL) of images taken during the examinations at hours (h) 0, 1 and 6 and days (d) 2, 3, 5 and 10.

RESULTS

At 0 h, GR was significantly lower in group E2 than in groups E1 and C (p < 0.05). There was an increase in GR values between 0 h and 10 d in group E2 and E3, but a decrease during the same time interval in group C (p < 0.05). In contrast, CON values of group E2 were lower (p < 0.05) at 0 h compared to other timepoints of examination and lower than in group C. HOM values were lower (p < 0.05) in groups E1, E2 and E3 than in group C on d 5 and d 10. HOM values were higher at 1 h compared to 6 h, d 2 and d 10 in group E3 (p < 0.05). By contrast to GR values, HOM values were higher in group C at 6 h and d 10 than they were in group E3. MGL values of group E2 were higher (p < 0.05) than in group C until d 10 and higher (p < 0.05) in group E3 than in group C at 6 h after treatment. In group E2 an increase of MGL values until d 2 was followed by a decrease (p < 0.05).

CONCLUSION

Echotexture parameters determined by the evaluation of sonographic B-mode images reflect changes in the endometrium and could be used for the evaluation of the recovery period after treatment of endometritis.

Diseases, reproductive performance, and changes in milk production associated with subclinical ketosis in dairy cows: a meta-analysis and review

Many studies have shown that subclinical ketosis (SCK) is associated with an increased risk of developing various diseases, reproductive disorders, and changes in milk production. The present work aims at producing an overview between this disorder and theses outcomes. A meta-analysis of the literature, including 131 different models from 23 papers, or a review when the literature was scarce was conducted. For each outcome, the odds ratio (OR), relative risk, or hazard ratio was presented for various moderators to reduce heterogeneity among the studies. The raw change in milk production associated with SCK was estimated and adjusted, taking into consideration the outcomes known to interact with milk production during the peripartum period. The results showed that 2 main categories of moderators had a significant effect on the adjusted risk. First, the adjustment made by defining SCK as (1) β-hydroxybutyrate concentration >1.4 mM, (2) nonesterified fatty acid (NEFA) concentration >0.4 mM prepartum, or (3) NEFA concentration >1.0 mM postpartum corrected the underestimated risk (despite low significance). This is because several trials reported the relevant risks using lower thresholds for the β-hydroxybutyrate or NEFA values. Using a low threshold leads to lower risk of disease compared with using a high threshold. Second, the correction produced using the polyfactorial terms corrected the overestimation of risk because many trials reported only univariable models. The relative risk or OR (95% confidence interval) related to abomasal displacement, clinical ketosis, early culling and death, metritis, placental retention, clinical mastitis, lameness, and a doubling of the SCC in cases with SCK were 3.33 (2.60-4.25), 5.38 (3.27-8.83), 1.92 (1.60-2.30), 1.75 (1.54-2.01), 1.52 (1.20-1.93), 1.61 (1.24-2.09), 2.01(1.64-2.44), and 1.42 (1.26-1.60), respectively. The precision level of the estimate depended on the outcome. The direct mean ± standard deviation of the 305-d milk losses associated with SCK were 251 ± 73 kg after adjusting for abomasal displacement, clinical ketosis, metritis, and placental retention. The OR (95% confidence interval) for first service calving risk in cases of SCK was 0.67 (0.53-0.83). The calving-to-first-service interval was 8 d longer and the calving-to-conception interval was 16 to 22 d longer in cows with SCK. The relationships among the different reproductive indicators were quantified in only 1 or 2 trials. The present work highlights the need to conduct further studies on the associations between SCK and the risks of diseases, changes in milk production, and reproductive parameters.

Comparison of bacterial endotoxin lipopolysaccharide concentrations in the blood, ovarian follicular fluid and uterine fluid: a clinical case of bovine metritis

We investigated the concentration of the bacterial endotoxin lipopolysaccharide (LPS) in the blood, ovarian follicular fluid and uterine fluid of a clinical case of bovine metritis. A 2-year-old lactating Holstein cow exhibited continuous fever >39.5°C for more than 2 weeks after normal calving. The cow produced a fetid, watery, red-brown uterine discharge from the vagina and was diagnosed with metritis. The LPS concentrations in plasma and uterine fluid were 0.94 and 6.34 endotoxin units (EU)/ml, respectively. One of seven follicles showed an extremely high level of LPS (12.40 EU/ml) compared to the other follicles (0.62-0.97 EU/ml). These results might suggest the presence of high concentration of LPS in follicles in cows with postpartum metritis.

Cardiac responses to palpation per rectum in lactating and nonlactating dairy cows

Interest in the monitoring of heart rate variability (HRV) has increased recently, as it gives more detailed and immediate information about the level of stress than traditional behavioral or hypothalamus-pituitary-adrenal measures. In this study, we evaluated heart rate (HR) and parasympathetic HRV parameters to monitor cardiac stress responses to palpation per rectum (PPR) in lactating (LACT; n = 11) and nonlactating (NLACT; n = 12) dairy cows. Heart rate and HRV were recorded from 40 min before PPR until 120 min after it was completed. Heart rate, the root mean square of successive differences (RMSSD), and the high-frequency component (HF) of HRV were analyzed by examining 5-min time windows. To compare cardiac responses to PPR between groups, changes in HR and HRV parameters were calculated as area under the curve (AUC) for LACT and NLACT cows. An immediate increase in HR was detected during PPR in both LACT (+21.4 ± 2.4 beats/min) and NLACT cows (+20.6 ± 2.3 beats/min); however, no differences were found between groups on the basis of parameters of AUC. The increase in HR in both groups along with a parallel decrease in RMSSD (LACT cows: -5.2 ± 0.4 ms; NLACT cows: -5.1 ± 0.4 ms) and HF [LACT cows: -10.1 ± 0.8 nu (where nu = normalized units); NLACT cows: -16.9 ± 1.2 nu] during PPR indicate an increase in the sympathetic, and a decrease in the parasympathetic tone of the autonomic nervous system. The increase in RMSSD (LACT cows: +7.3 ± 0.7 ms; NL cows: +17.8 ± 2.2 ms) and in HF (LACT cows: +24.3 ± 2.6 nu; NLACT cows: +32.7 ± 3.5 nu) immediately after PPR indicated a rapid increase in parasympathetic activity, which decreased under the baseline values 10 min following PPR. The amplitude and the maximum RMSSD and HF values were greater in NLACT cows than in LACT animals, suggesting a higher short-term cardiac responsiveness of NLACT cows. However, the magnitude and the duration of the stress response were greater in LACT cows, as indicated by the analysis of AUC parameters (area under the HRV response curve and time to return to baseline). Cow response to the PPR was more prominent in parasympathetic HRV measures than in HR. Based on our results, the effect of PPR on the cows' cardiac stress responses may have an impact on animal welfare on dairy farms, and investigating the effect of lactation on the cardiac stress reactions could prove useful in modeling bovine stress sensitivity. Further research is needed to find out whether the differences due to lactation are physiological or management related.

Incidence of subclinical endometritis and its effects on reproductive performance of crossbred dairy cows

In dairy cattle, uterine infections are not life threatening and often unavoidable; however, they reduce fertility and increase the production costs of properties. The aim of this study was to evaluate the incidence of subclinical endometritis from 32 to 70 days in milk (DIM) and its effects on the reproductive performance of crossbred dairy cows. Lactating cows (Holstein/Gir; n = 172), with no history of retained placenta, without clinical signs of uterine infection were used. The body condition score (BCS) was evaluated on a scale from 1 to 5. Ultrasound examination was performed to evaluate uterine lining and ovarian activity, while vaginal mucus was analyzed by gloved hand. The diagnosis of subclinical endometritis was performed by endometrial cytobrush technique. The samples were collected, stained, and examined microscopically; positive cases for subclinical endometritis were considered with the presence of ≥5 % of neutrophils. Later, the cows were submitted to conventional artificial insemination or timed artificial insemination. The incidence of subclinical endometritis in the herd was 26 %, and this was not affected by the season of calving, presence of corpus luteum, DIM, and parity. Cows with a BCS ≤2.50 had a higher incidence of subclinical endometritis. The conception rate to first insemination and pregnancy rate at 150 days postpartum were not influenced by the presence of subclinical endometritis in crossbred dairy cows.

Effects of physiological and/or disease status on the response of postpartum dairy cows to synchronization of estrus using an intravaginal progesterone device

Progesterone treatments are used to increase submission rates in postpartum dairy cows; however, in many cases the protocol is used as a blanket therapy for all cows without regard for physiological or disease state. The objective of this study was to identify the physiological or disease classes of cows that respond well (or not) to synchronization of estrus via progesterone. Dairy cows (n = 402) were monitored peri and postpartum to establish their physiological or disease status. Animals were classified as having negative energy balance, clinical lameness, uterine infection (UI), anovulatory anestrus, high somatic cell counts, and healthy (H). Blood samples were collected at five different time points and analyzed for metabolites. All animals received an 8-day controlled internal drug release protocol, which included GnRH at insertion and PGF2α the day before removal. Response to the protocol was determined by visual observation of estrus synchronization. Conception rate was determined by ultrasonography between Days 32 and 35 after artificial insemination. Animals without UI were 1.9 times more likely to respond and two times more likely to be confirmed pregnant than those with UI. There was no relationship between negative energy balance and clinical lameness in the visual estrous response, but both conditions were associated with reduced conception rates. Dairy cows in anovulatory anestrus responded successfully to the protocol in both estrous response and conception rates. High glutathione peroxidase concentrations had a positive effect on conception rates, whereas high non-esterified fatty acids and beta-hydroxybutyrate had a negative effect on the estrous response. In conclusion, disease and physiological states of dairy cows determined the response to progesterone-based synchronization. The more disease or physiological problems the cows had, the lower the estrous response and conception rates; cows with these problems were not ideal candidates for synchronization. Both anestrus and healthy dairy cows were good responders to progesterone-based synchronization.

Does Coxiella burnetii affect reproduction in cattle? A clinical update

Q fever is a zoonosis produced by Coxiella burnetii, a bacterium that is widely distributed worldwide. Domestic ruminants are the most important source of C. burnetii for human infection. In sheep and goats, abortion is the main clinical consequence of infection, yet the symptoms described in cattle have so far been inconsistent. Q fever has been also scarcely reported in cattle, most likely because of its difficult diagnosis at the farm level and because of the many existing responsible C. burnetii strains. In this report, the effects of C. burnetii infection or Q fever disease on the reproductive behaviour of dairy cattle are reviewed, with special emphasis placed on the scarcity of data available and possible control actions discussed.

Invited review: Systematic review of diagnostic tests for reproductive-tract infection and inflammation in dairy cows

The objective of this study was to conduct a systematic and critical appraisal of the quality of previous publications and describe diagnostic methods, diagnostic criteria and definitions, repeatability, and agreement among methods for diagnosis of vaginitis, cervicitis, endometritis, salpingitis, and oophoritis in dairy cows. Publications (n=1,600) that included the words "dairy," "cows," and at least one disease of interest were located with online search engines. In total, 51 papers were selected for comprehensive review by pairs of the authors. Only 61% (n=31) of the 51 reviewed papers provided a definition or citation for the disease or diagnostic methods studied, and only 49% (n=25) of the papers provided the data or a citation to support the test cut point used for diagnosing disease. Furthermore, a large proportion of the papers did not provide sufficient detail to allow critical assessment of the quality of design or reporting. Of 11 described diagnostic methods, only one complete methodology, i.e., vaginoscopy, was assessed for both within- and between-operator repeatability (κ=0.55-0.60 and 0.44, respectively). In the absence of a gold standard, comparisons between different tests have been undertaken. Agreement between the various diagnostic methods is at a low level. These discrepancies may indicate that these diagnostic methods assess different aspects of reproductive health and underline the importance of tying diagnostic criteria to objective measures of reproductive performance. Those studies that used a reproductive outcome to select cut points and tests have the greatest clinical utility. This approach has demonstrated, for example, that presence of (muco)purulent discharge in the vagina and an increased proportion of leukocytes in cytological preparations following uterine lavage or cytobrush sampling are associated with poorer reproductive outcomes. The lack of validated, consistent definitions and outcome variables makes comparisons of the different tests difficult. The quality of design and reporting in future publications could be improved by using checklists as a guideline. Further high-quality research based on published standards to improve study design and reporting should improve cow-side diagnostic tests. Specifically, more data on intra- and interobserver agreement are needed to evaluate test variability. Also, more studies are necessary to determine optimal cut points and time postpartum of examination.

Lipopolysaccharide (LPS) inhibits steroid production in theca cells of bovine follicles in vitro: distinct effect of LPS on theca cell function in pre- and post-selection follicles

In postpartum dairy cows, lipopolysaccharide (LPS) derived from gram-negative bacteria such as Escherichia coli causes uterine inflammation and leads to ovarian dysfunction. The aim of this study was to determine the effect of LPS on steroid production in bovine theca cells at different stages of follicular development. Theca cells isolated from pre- and post-selection follicles (PRFs, <8.5 mm in diameter, and POFs, >8.5 mm in diameter, respectively) of bovine ovaries were exposed to LPS under luteinizing hormone (LH) conditions, estradiol (E2) conditions or both conditions in vitro. Bovine theca cells expressed the LPS receptor gene complex: Toll-like receptor 4 (TLR4), CD14 and MD2. LPS suppressed progesterone (P4) and androstenedione (A4) production with downregulation of steroidogenic enzyme transcripts when theca cells were stimulated with LH. By contrast, LPS did not affect P4 or A4 production when theca cells were stimulated with E2. P4 and A4 production in theca cells from PRFs was suppressed by LPS as early as at 48 h of culture, whereas the effect of LPS on theca cells from POFs was observed at 96 h of culture. The results demonstrate that LPS inhibits steroid production in theca cells under LH conditions. Moreover, theca cells from POFs showed a slower response to LPS compared with that of theca cells from PRFs, which might imply a distinct effect of LPS on follicles at different developmental stages. These findings suggest a possible mechanism of ovarian dysfunction and subsequent infertility in cows with endometritis.

Spatio-specific regulation of endocrine-responsive gene transcription by periovulatory endocrine profiles in the bovine reproductive tract

In cattle, pro-oestrous oestradiol and dioestrous progesterone concentrations modulate endometrial gene expression and fertility. The aim was to compare the effects of different periovulatory endocrine profiles on the expression of progesterone receptor (PGR), oestrogen receptor 2 (ESR2), oxytocin receptor (OXTR), member C4 of aldo-keto reductase family 1 (AKR1C4), lipoprotein lipase (LPL), solute carrier family 2, member 1 (SLC2A1) and serpin peptidase inhibitor, clade A member 14 (SERPINA14): (1) between uterine horns ipsi- and contralateral to the corpus luteum (CL), (2) between regions of the ipsilateral horn and (3) in the vagina. Endometrium and vagina tissue samples were collected from cows that ovulated a larger (large follicle-large CL, LF-LCL; n=6) or smaller follicle (small follicle-small CL, SF-SCL; n=6) 7 days after oestrus. Cows in the LF-LCL group had a greater abundance of transcripts encoding ESR2, AKR1C4, LPL, SLC2A1 and SERPINA14, but a reduced expression of PGR and OXTR in the endometrium versus the SF-SCL group (PPGR and OXTR was greater in the contralateral compared with the ipsilateral horn (PPGR, ESR2, LPL, SLC2A1 and SERPINA14 (P<0.05). Different periovulatory endocrine profiles, i.e. LF-LCL or SF-SCL, did not influence gene expression in the vagina and had no interaction with inter- or intra-uterine horn gene expression. In conclusion, inter- and intra-uterine horn variations in gene expression indicate that the expression of specific genes in the bovine reproductive tract is location dependent. However, spatial distribution of transcripts was not influenced by distinct periovulatory sex-steroid environments.

Genetic merit for fertility traits in Holstein cows: IV. Transition period, uterine health, and resumption of cyclicity

The objective of this study was to monitor the dry matter intake (DMI), metabolic status, uterine health, and resumption of cyclicity in cows with similar genetic merit for milk production traits but with either good (Fert+) or poor genetic merit (Fert-) for fertility traits. Twenty-six cows were enrolled in the study and data are reported for 15 Fert+ and 10 Fert- cows that completed the study. All cows received a total mixed ration diet during early lactation and were turned out to pasture in late spring. Dry matter intake was recorded daily from wk -2 to 5 relative to parturition. Blood metabolites and metabolic hormones were measured from wk -2 to 8 relative to parturition. Milk production, body condition score, and body weight until wk 35 of lactation are reported. To monitor uterine health, vaginal mucus was scored weekly on a scale of 0 (no pus) to 3 (≥ 50% pus) from parturition to wk 8 and uterine polymorphonuclear neutrophil count was measured at wk 3 and 6 postpartum. Prepartum DMI was similar between genotypes, but Fert+ cows had significantly greater DMI than Fert- cows (19.7 vs. 16.8 kg of dry matter/d) during the postpartum period. Energy balance at wk 1 was significantly greater in Fert+ cows than in Fert- cows [2.3 vs. -1.12 unité fourragère lait (UFL)/d]. The Fert+ cows had significantly greater daily milk solids production (1.89 vs. 1.74 kg/d) and tended to have greater daily milk yield (24.2 vs. 22.3 kg/d). The Fert+ cows had significantly greater mean circulating insulin-like growth factor-I (102.62 vs. 56.85 ng/mL) and tended to have greater mean circulating insulin (3.25 vs. 2.62 μIU/mL) compared with Fert- cows from wk -2 to 8 relative to parturition. Mean circulating glucose (3.40 vs. 3.01 mmol/L) concentrations were significantly greater in Fert+ cows compared with Fert- cows from wk -2 to 3 relative to parturition. The Fert+ cows maintained significantly greater mean body condition score throughout lactation compared with Fert- cows (2.98 vs. 2.74 units). Moreover, Fert+ cows had better uterine health compared with Fert- cows, as evidenced by lower weekly vaginal mucus scores from wk 2 to 6 postpartum and, based on uterine cytology, smaller proportions were classified as having endometritis at wk 3 (0.42 vs. 0.78) and 6 (0.25 vs. 0.75). Also, a significantly greater proportion of Fert+ cows had resumed cyclicity by wk 6 postpartum (0.86 vs. 0.20) compared with Fert- cows. Hence, we report for the first time that genetic merit for fertility traits is associated with postpartum uterine health status. Superior uterine health and earlier resumption of cyclicity may be mediated through differences in DMI, energy balance, insulin, insulin-like growth factor-I, and body condition score profiles. Importantly, phenotypic improvement in fertility traits was achieved without antagonizing milk production.

Postpartal subclinical endometritis alters transcriptome profiles in liver and adipose tissue of dairy cows

Transcriptome alterations in liver and adipose tissue of cows with subclinical endometritis (SCE) at 29 d postpartum were evaluated. Bioinformatics analysis was performed using the Dynamic Impact Approach by means of KEGG and DAVID databases. Milk production, blood metabolites (non-esterified fatty acids, magnesium), and disease biomarkers (albumin, aspartate aminotransferase) did not differ greatly between healthy and SCE cows. In liver tissue of cows with SCE, alterations in gene expression revealed an activation of complement and coagulation cascade, steroid hormone biosynthesis, apoptosis, inflammation, oxidative stress, MAPK signaling, and the formation of fibrinogen complex. Bioinformatics analysis also revealed an inhibition of vitamin B3 and B6 metabolism with SCE. In adipose, the most activated pathways by SCE were nicotinate and nicotinamide metabolism, long-chain fatty acid transport, oxidative phosphorylation, inflammation, T cell and B cell receptor signaling, and mTOR signaling. Results indicate that SCE in dairy cattle during early lactation induces molecular alterations in liver and adipose tissue indicative of immune activation and cellular stress.

Mucin 1 and cytokines mRNA in endometrium of dairy cows with postpartum uterine disease or repeat breeding

Mucin (MUC) 1 is an inducible innate immune effector, an important component of defense against bacterial invasion, and is linked with infertility in humans. The objectives were to evaluate messenger RNA (mRNA) expression of MUC1 and cytokine genes in the endometrium of cows with various postpartum uterine inflammatory conditions or with a history of repeat breeding. Endometrial samples were collected from lactating dairy cows diagnosed with metritis (n = 4), endometritis (n = 4), subclinical endometritis (n = 4), or no uterine pathology (normal; n = 4). In addition, endometrial samples were collected from repeat breeder cows with (n = 4) or without (n = 4) subclinical endometritis, and unaffected cows (n = 4). Quantitative polymerase chain reaction was used to determine mRNA abundances of MUC1, Toll-like receptor (TLR) 4, interleukin (IL) 1β, IL6, IL8, tumor necrosis factor (TNF) α, insulin-like growth factor (IGF) 1, and IGF-binding protein (BP) 2. The mRNA expressions were significantly greater for cows with metritis and clinical endometritis compared with cows with no uterine inflammation, except for IL6. However, mRNA expressions for these target genes were not different for cows with subclinical endometritis, compared with cows without uterine inflammation, except for IL1β and TNFα mRNA (P < 0.01). All mRNA expressions were greater (P < 0.001) for repeat breeder cows with subclinical endometritis compared with normal cows. However, in repeat breeder cows without subclinical endometritis, only expressions of MUC1, IGF1, and IGF BP2 were greater compared with normal cows (P < 0.01). Based on functional protein networks, there were significant associations between these transcripts. In conclusion, endometrial expressions of MUC1 and cytokine genes differed among normal, fertile versus diseased, and subfertile dairy cows. Perhaps, these altered gene expressions contribute to endometrial insufficiency and consequently pregnancy wastage.

Interactions between negative energy balance, metabolic diseases, uterine health and immune response in transition dairy cows

The biological cycles of milk production and reproduction determine dairying profitability thus making management decisions dynamic and time-dependent. Diseases also negatively impact on net earnings of a dairy enterprise. Transition cows in particular face the challenge of negative energy balance (NEB) and/or disproportional energy metabolism (fatty liver, ketosis, subacute, acute ruminal acidosis); disturbed mineral utilization (milk fever, sub-clinical hypocalcemia); and perturbed immune function (retained placenta, metritis, mastitis). Consequently NEB and reduced dry matter intake are aggravated. The combined effects of all these challenges are reduced fertility and milk production resulting in diminishing profits. Risk factors such as NEB, inflammation and impairment of the immune response are highly cause-and-effect related. Thus, managing cows during the transition period should be geared toward reducing NEB or feeding specially formulated diets to improve immunity. Given that all cows experience a reduced feed intake and body condition, infection and inflammation of the uterus after calving, there is a need for further research on the immunology of transition dairy cows. Integrative approaches at the molecular, cellular and animal level may unravel the complex interactions between disturbed metabolism and immune function that predispose cows to periparturient diseases.

The effect of metritis on luteal function in dairy cows

Background

Disturbed uterine involution impairs ovarian function in the first weeks after calving. This study analyzed the long-term effect of metritis on luteal function of 47 lactating Holstein-Friesian cows during the first four postpartum estrous cycles. Cows with abnormal uterine enlargement and malodorous lochia were classified as having metritis (group M, n = 18), and all others were considered healthy (group H, n = 29). Luteal size was measured once between days 9 and 13 of the first (group H, n = 11; group M, n = 12), second (group H, n = 23; group M, n = 18) and fourth (group H, n = 11; group M, n = 7) postpartum luteal phases. Serum progesterone concentration was measured at the same time. Sixteen cows (group H, n = 9; group M, n = 7) underwent transvaginal luteal biopsy for gene expression analysis of steroidogenic regulatory proteins during the second and fourth cycles. Cows with persistence of the corpus luteum (CL) underwent determination of luteal size, luteal biopsy and serum progesterone measurement once between days 29 and 33, followed by prostaglandin treatment to induce luteolysis. The same procedures were repeated once between days 9 and 13 of the induced cycle.

Results

The cows in group M had smaller first-cycle CLs than the cows in group H (p = 0.04), but progesterone concentrations did not differ between groups. Luteal size, progesterone concentration and gene expression did not differ between the two groups during the second and fourth cycles. Compared with healthy cows (10%), there was a trend (p = 0.07) toward a higher prevalence of persistent CLs in cows with metritis (33%). Persistent CLs were limited to the first cycle. Persistent CLs and the induced cyclic CLs did not differ with regard to the variables investigated.

Conclusions

An effect of metritis on luteal activity was apparent in the first postpartum estrous cycle. However, after the first postpartum cycle, no differences occurred in analyzed parameters between metritis and control cows. Therefore, a metritis is able to impair luteal activity transiently, but does not seem to have a long-term effect on luteal function.

Associations among serum pro- and anti-inflammatory cytokines, metabolic mediators, body condition, and uterine disease in postpartum dairy cows

BACKGROUND

Adipose tissue is an active endocrine organ which secretes a wide range of hormones and protein factors, collectively termed adipokines. Adipokines affect appetite and satiety, glucose and lipid metabolism, inflammation and immune functions. The objectives were to evaluate serum concentrations of adipokines (adiponectin, leptin, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6) in lactating dairy cows with postpartum uterine inflammatory conditions (metritis, clinical endometritis or subclinical endometritis) and in cows experiencing loss of body condition, and to assess the relationship of adipokines and body condition loss in the establishment of persistent uterine inflammatory conditions.

METHODS

Lactating multiparous Holstein cows (N = 40), with body condition scores (BCS) from 2 to 4 (eight cows for each 0.5 score increment) were enrolled. Body condition was monitored for all cows weekly for 7 weeks post calving; cows with uterine inflammatory conditions were also re-evaluated 2 weeks later. Blood samples were collected from 1 week prior to calving to 7 weeks after calving for determination of serum concentrations of adipokines, insulin and insulin like growth factor (IGF)-1.

RESULTS

Cows with metritis or clinical endometritis had higher serum concentrations of adiponectin, leptin, TNF-alpha, IL-1beta and IL-6 compared to normal cows (P < 0.05). Furthermore, serum leptin, TNF-alpha, IL-1beta and IL-6 were higher in cows with subclinical endometritis compared to normal cows (P < 0.05), and insulin and IGF-1 concentrations were lower in cows with metritis or clinical endometritis. Cows with low BCS (2 and 2.5) had significantly higher adiponectin, TNF-alpha, IL-1beta and IL-6 than those with high BCS (3 to 4). Cows with persistent uterine inflammatory conditions had higher adiponectin, leptin TNF-alpha, IL-1beta and IL-6 and insulin compared to normal and spontaneously recovered cows, except for IGF-1 (P < 0.05).

CONCLUSIONS

Serum concentrations of adipokines, insulin, and IGF-1 had significant associations with BCS categories (low vs. high) and postpartum uterine inflammatory conditions. Perhaps loss of body condition mediated increases in anti- and pro-inflammatory cytokines, whereas increased pro- and anti-inflammatory cytokines concentrations mediated body condition loss and thereby prolonged persistence of uterine inflammation in dairy cows.

Welfare-positive management and nutrition for the dairy herd: a European perspective

As European dairy farms become larger and diverge between grass-based and fully housed systems, interest in the welfare of the dairy cow and related environmental issues by consumers and legislators is increasing. These pressures mean that good nutrition and management, which underpin much dairy cow welfare, is critical. Despite considerable research into the management and nutrition of the dairy cow from calf to adulthood there is much on-farm variability in its application. While the incidences of many endemic diseases are reduced most are still significant, for example lameness. In addition, trade and climate change are bringing a more diverse range of pathogens, parasites and pests into Northern Europe. Housing aspects are limited in application by economics and in most cases still do not match grazing for welfare in temperate climates. Genomic technologies offer increased opportunities to breed for 'robustness' but like 'precision animal management systems' have still to be fully exploited.

Effects of 1 or 2 treatments with prostaglandin F₂α on subclinical endometritis and fertility in lactating dairy cows inseminated by timed artificial insemination

The objectives of the current study were to investigate the efficacy of PGF₂α as a therapy to reduce the prevalence of subclinical endometritis and improve pregnancy per artificial insemination (P/AI) in cows subjected to a timed artificial insemination (AI) program. A total of 1,342 lactating Holstein dairy cows were allocated randomly at 25 ± 3 d in milk (DIM) to remain as untreated controls (control, n=454) or to receive a single PGF₂α treatment at 39 ± 3 DIM (1PGF, n=474) or 2 treatments with PGF(α at 25 ± 3 and 39 ± 3 DIM (2PGF, n=414). All cows were enrolled in the double Ovsynch program at 48 ± 3 DIM and were inseminated at 75 ± 3 DIM. A subset of 357 cows had uterine samples collected for cytological examination at 25 ± 3, 32 ± 3, and 46 ± 3 DIM to determine the percentage of polymorphonuclear leukocytes (PMNL). Subclinical endometritis was defined by the presence of ≥ 5% PMNL. Vaginal discharge score was evaluated at 25 ± 3 DIM and used to define the prevalence of purulent vaginal discharge. Body condition score was assessed at 25 ± 3 DIM. Pregnancy was diagnosed 32 d after AI and reconfirmed 28 d later. At 32 ± 3 DIM, the prevalence of subclinical endometritis was reduced by treatment with PGF₂α at 25 ± 3 DIM in 2PGF (control=23.5% vs. 1PGF=28.3% vs. 2PGF=16.7%); however, this benefit disappeared at 46 ± 3 DIM, and 14% of the cows remained with subclinical endometritis. One or 2 treatments with PGF₂α did not influence P/AI on d 32 or 60 after timed AI, which averaged 39.9 and 35.2%. Similarly, treatment with PGF₂α had no effect on pregnancy loss between 32 and 60 d of gestation (11.9%). Cows diagnosed with both purulent vaginal discharge and subclinical endometritis had the lowest P/AI and the highest pregnancy loss compared with those diagnosed with only 1 of the 2 diseases or compared with cows having no diagnosis of uterine diseases. Interestingly, subclinical endometritis depressed P/AI and increased pregnancy loss only when it persisted until 46 DIM. On d 32 after AI, cows not diagnosed with subclinical endometritis and those that resolved subclinical endometritis by 46 DIM had greater P/AI than those that remained with subclinical endometritis at 46 DIM (45.4 and 40.0 vs. 25.0%, respectively). Similar to P/AI, cows not diagnosed with subclinical endometritis and those that resolved subclinical endometritis by 46 DIM had less pregnancy loss than those with subclinical endometritis at 46 DIM (9.6 and 13.5 vs. 43.9%, respectively). One or 2 treatments with PGF₂α before initiation of the timed AI program were unable to improve uterine health, P/AI, and maintenance of pregnancy in lactating dairy cows. Cows diagnosed with both purulent vaginal discharge and subclinical endometritis had the greatest depressions in measures of fertility at first AI, particularly when subclinical endometritis persisted in the early postpartum period.

Incidência de endometrite citológica e desempenho reprodutivo em vacas de corte Nelore

Avaliaram-se a incidência de endometrite citológica dos 29 aos 90 dias pós-parto e seus efeitos sobre o desempenho reprodutivo de vacas de corte Nelore submetidas a uma estação de monta (EM) de 90 dias. Foram utilizadas 49 matrizes Nelores, sem histórico de retenção de placenta, sem a presença de uma infecção uterina clínica, e com escore de condição corporal acima de 2,5. Realizou-se exame ultrassonográfico para avaliar a parede uterina e a atividade ovariana. O diagnóstico de endometrite citológica foi feito pela técnica de lavagem uterina, considerando-se caso de endometrite ≥5% de neutrófilos em cada lâmina. A incidência de endometrite citológica do rebanho foi de 22%, não diferindo entre as categorias analisadas (primíparas versus multíparas) (P>0,05), a taxa de concepção à primeira inseminação também foi semelhante entre primíparas versus multíparas (P>0,05), porém a taxa de gestação ao final da EM foi maior nas vacas multíparas (83,8%) quando comparadas às primíparas (50,0%) (P<0,05). A presença ou ausência da endometrite citológica não influenciou a taxa de concepção (P>0,05), tampouco a taxa de gestação ao final da EM (P>0,05). Conclui-se que o uso da citologia endometrial não se justifica como ferramenta de diagnóstico em vacas de corte Nelore.

Effects of bovine viral diarrhoea virus on the fertility of cows

The aim of the present study was to determine the possible relationship between bovine viral diarrhoea (BVD) virus infection and the appearance of cervical mucous discharge (CMD) and the reproductive performance of cows in oestrus. For this purpose, CMD from 97 Holstein cows in oestrus was evaluated visually before artificial insemination (AI). Cows in oestrus were inseminated with frozen semen free from BVD virus (BVDV). Blood samples were tested by enzyme-linked immunoassay (ELISA) for antigen (Ag) and antibodies (Ab) of BVDV. The presence of the BVDV genome in cervical mucus samples was tested by reverse transcriptase-polymerase chain reaction (RT-PCR). The presence of BVDV Ab, Ag or genome was not associated with abnormal cervical mucous discharge (A-CMD). However, the presence of BVDV Ag (but not of the BVDV Ab) in blood samples was associated with a lower first service conception rate (FSCR; 27.8 vs. 70.9%; P < 0.01), indicating that BVDV viraemia at the time of AI has a negative effect on the fertility of cows.

Influence of energy balance on the antimicrobial peptides S100A8 and S100A9 in the endometrium of the post-partum dairy cow

Uterine inflammation occurs after calving in association with extensive endometrial remodelling and bacterial contamination. If the inflammation persists, it leads to reduced fertility. Chronic endometritis is highly prevalent in high-yielding cows that experience negative energy balance (NEB) in early lactation. This study investigated the effect of NEB on the antimicrobial peptides S100A8 and S100A9 in involuting uteri collected 2 weeks post partum. Holstein-Friesian cows (six per treatment) were randomly allocated to two interventions designed to produce mild or severe NEB (MNEB and SNEB) status. Endometrial samples were examined histologically, and the presence of neutrophils, macrophages, lymphocytes and natural killer cells was confirmed using haematoxylin and eosin and immunostaining. SNEB cows had greater signs of uterine inflammation. Samples of previously gravid uterine horn were used to localise S100A8 and S100A9 by immunohistochemistry. Both S100 proteins were present in bovine endometrium with strong staining in epithelial and stromal cells and in infiltrated leucocytes. Immunostaining was significantly higher in SNEB cows along with increased numbers of segmented neutrophils. These results suggest that the metabolic changes of a post-partum cow suffering from NEB delay uterine involution and promote a chronic state of inflammation. We show that upregulation of S100A8 and S100A9 is clearly a key component of the early endometrial response to uterine infection. Further studies are warranted to link the extent of this response after calving to the likelihood of cows developing endometritis and to their subsequent fertility.

The postpartum endometrial inflammatory response: a normal physiological event with potential implications for bovine fertility

After calving, the bovine endometrium undergoes marked morphological and functional changes that are necessary for subsequent re-breeding. Regulation and integration of these key events are largely uncharacterised. Here, endometrial swabs and biopsies were taken at 15, 30 and 60 days postpartum (DPP) from 13 healthy primiparous cows, 10 of which subsequently conceived, with a view to characterising innate and inflammatory gene expression profiles. Endometrial biopsies exhibited severe inflammation (>75 leukocytes per high-power field) at 15 DPP, which had begun to resolve by 30 DPP and had completely resolved by 60 DPP. The severe inflammation at 15 DPP coincided with uterine infection in all cows and a significant increase (P < 0.05) in the expression of all of 16 genes investigated, including CD45, IL8, IL6, IL1, TNF, TAP, SAA3 and HP at 15 DPP, relative to 60 DPP. All of these parameters had begun to return to normal physiological levels at 30 DPP. Systemically, serum protein concentrations of IL-8 were elevated at 15 DPP compared with 60 DPP (78 pgmL(-1)vs 48 pgmL(-1); P = 0.02). These results indicate that endometrial inflammation, leukocyte infiltration and increased expression of pro-inflammatory, antimicrobial and acute-phase protein genes are expected features of the postpartum period, critical to bacterial clearance and uterine involution.

Therapy of bovine endometritis with prostaglandin F2α: a meta-analysis

The objective of the conducted meta-analysis was to assess the efficacy of the treatment of bovine endometritis with PGF(2α) by statistical means. Postpartum uterine infections have a high prevalence and a very negative effect on reproductive performance in dairy cattle. Because of a wide discordance between research results, a meta-analysis of the efficacy of the treatment of bovine endometritis with PGF(2α) was conducted. A comprehensive literature search was performed using online databases to reveal a total of 2,307 references. In addition, 5 articles were retrieved by reviewing citations. After applying specific exclusion criteria and evaluating specific evidence parameters, 5 publications, comprising 6 trials, were eligible for being analyzed by means of meta-analysis. Data for each trial were extracted and analyzed using meta-analysis software Review Manager (version 5.1; The Nordic Cochrane Centre, Copenhagen, Denmark). Estimated effect sizes of PGF(2α) were calculated on calving to first service and calving to conception interval. Prostaglandin F(2α) treatment of cows with chronic endometritis had a negative effect on both reproductive performance parameters. Heterogeneity was substantial for calving to first service and calving to conception interval [I(2) (measure of variation beyond chance)=100 and 87%, respectively]; therefore, random-effects models were used. Sensitivity analysis as well as subgroup analysis showed that the performance of randomization was influential in modifying effect size of PGF(2α) treatment. The funnel plot illustrated a publication bias toward smaller studies that reported a prolonged calving to conception interval after a PGF(2α) treatment. We conclude that the investigation of this subject by means of meta-analysis did not reveal an improvement of reproductive performance of cows with endometritis after treatment with PGF(2α). Furthermore, there is a shortage of comparable high quality studies investigating reproductive performance after PGF(2α) treatment of cows with chronic endometritis.

Using temperature-sensing reticular boluses to aid in the detection of production diseases in dairy cows

The objective of this study was to investigate associations between increases in reticular temperature (RT) in dairy cows and the diagnosis of metritis, mastitis, lameness, and pneumonia by dairy personnel. A prospective case-control study was conducted on a 2,175-cow dairy operation in Colorado from May 2010 to April 2011. Each cow received an orally administered temperature sensing reticular bolus after parturition and RT measurements were recorded 3 times per day as lactating cows exited the milking parlor. A cow was identified as having an increased RT when a deviation of 0.8°C above baseline (average of readings of previous 10d) was recorded by the TempTrack software (DVM Systems, LLC, Greeley, CO). During the same study period, dairy personnel without access to RT data recorded health events and classified them according to clinical signs observed. A total of 201 health events (cases) were included in the data analysis. Cows with clinical mastitis and pneumonia had significantly higher odds (6.7 and 7.5 times higher, respectively) of having an increased RT of 0.8°C above their baseline within 4d preceding diagnosis when compared with control cows. Specificity and sensitivity for an increase of 0.8°C above baseline RT within 4d of disease diagnosis was 76.85 and 66.97% for mastitis, and 69.23 and 76.92% for pneumonia, respectively. No significant difference in RT was found for cows diagnosed with lameness or metritis. Results of this study suggest that RT monitoring can be a useful tool in the early detection of mastitis and pneumonia in dairy cows.

Short communication: Evaluation of vaginal discharge following treatment with a progesterone insert

Yellowish discharge after application of intravaginal progesterone releasing inserts is frequently observed in cows. The objective of this study was to compare the bacteriological contamination of the vagina and uterus before and after a treatment with a progesterone insert in heifers. Forty-two Holstein heifers received a progesterone releasing insert [Eazi-Breed controlled internal drug release (CIDR) insert; Pfizer Animal Health, Berlin, Germany] for 7d. The protruding tail had been removed from half of the inserts (no tail group: n=21; tail group: n=21). Nine heifers from the tail group lost the insert within the 7-d treatment interval and were excluded. Heifers identified in estrus were artificially inseminated on d 9 or 10. Vaginal discharge was scored on a 4-point scale [vaginal discharge score (VDS) 0 to 3] and vaginal swabs were taken for bacteriological examination on d 0 and 7 and the day of artificial insemination (AI). Furthermore, cytological and bacteriological samples were obtained from the uterus on d 7 and the day of AI. On d 0, coliforms and Streptococcus spp. were found in vaginal swabs of 21 heifers (64%). On d 7, all heifers showed purulent vaginal discharge (VDS 2 to 3). The VDS was higher in the tail group compared with the no tail group. Arcanobacterium pyogenes, coliforms, and Streptococcus spp. were isolated from the vaginal swabs in 32 of 33 (96%) heifers on d 7. On the day of AI, VDS had improved to 0 or 1 in 96% of the heifers. However, A. pyogenes, coliforms, and Streptococcus spp. were still isolated in 17 of 33 (53%) heifers from the vagina and in 32 of 33 (96%) heifers from the endometrium. Endometrial cytology revealed polymorphonuclear neutrophils (PMN) in 11 heifers (6 to 32% PMN). Five samples exceeded the threshold of 5% PMN, and 2 samples exceeded the 10% PMN threshold, indicative of subclinical endometritis. In conclusion, pyogenic bacteria were found in the vagina and uterus on d 7 and the day of AI after intravaginal progesterone treatment. The severity of the discharge was affected by the protruding tail of the insert.

Evaluation of two doses of ceftiofur crystalline free acid sterile suspension for treatment of metritis in lactating dairy cows

The objectives of this study were to evaluate efficacy of a 2-dose regimen of ceftiofur crystalline free acid sterile suspension (CCFA-SS) for treatment of acute metritis in lactating dairy cows under field conditions and to provide additional safety and injection site tolerance data for injections at the base of the ear. Cows at 15 dairies with rectal temperature ≥ 39.5°C and fetid uterine discharge ≤ 10 d postcalving were randomly assigned by blocks of 2, based on order of entry and without regard to parity, to treatment with saline (1.5 mL/45.5 kg of body weight, n=509) or CCFA-SS (6.6 mg of ceftiofur equivalents/kg of body weight, n=514). Treatments were administered by subcutaneous injection in the posterior aspect of the ear where it attaches to the head; the first dose was administered on study d 0 and the second dose was administered in the contra lateral ear on study d 3. Rectal temperatures were recorded on study d 1 to 4 and 5 or 6 and cows were clinically evaluated daily from study d 1 to 13. Cows that exhibited increased adverse clinical signs of poor health or complications associated with metritis were categorized as a treatment failure and administered escape therapy. Each cow received a veterinary physical examination on study d 5 or 6 to determine if she should be removed from the study and on study d 14 to determine clinical cure or failure to cure. Clinical cure was defined as rectal temperature <39.5°C and non-fetid and purulent or mucopurulent discharge on study d 14 and no escape therapy administered. The injection procedure was scored after each injection (study d 0 and 3) and injection sites and ear carriage were scored on study d 5 or 6, 14, and 57±3. Of the 1,023 cows enrolled, 7 were completely censored due to protocol deviations and 34 were removed for protocol deviations or medical conditions not related to metritis. Clinical cure rate was higher for CCFA-SS than for saline (74.3 vs. 55.3%) and rectal temperatures for each of study d 1 to 5 or 6 were lower for CCFA-SS than saline. Injection procedure indices showed that CCFA-SS could be practically and safely administered using commercial dairy facilities. Although injection site scores were higher for CCFA-SS than saline at study d 5 or 6 and 14, ≥98.6% of ears were normal on d 57±3. Thus, a 2-dose treatment with CCFA-SS given 72h apart increased metritis clinical cure rate and was well tolerated in dairy cows.

Time course of defense mechanisms in bovine endometrium in response to lipopolysaccharide

Endometritis caused by uterine infection after calving reduces fertility and causes major economic losses to the dairy industry. This study investigated the time course of an inflammatory response in bovine endometrium triggered by exposure to bacterial endotoxin lipopolysaccharide (LPS). Mixed endometrial epithelial and stromal cells (9:1 ratio) were grown to confluence as a model system and treated with an optimized dose of 100 ng/ml LPS in vitro. Gene expression responses were measured using quantitative PCR, and gene products were investigated using assays of culture medium and Western blotting. Of 17 candidate genes tested initially, LPS treatment for 24 h up-regulated mRNA expression of TLR4 signaling (TLR4, CD14), cytokines (IL1B, TNF), chemokines (IL8, CXCL5), antimicrobial peptides (LAP, S100A8, S100A9, S100A12), and matrix metalloproteinases (MMP1, MMP13). A 48 h, LPS time course study showed that TNF increased first at 1 h, followed by peak expression of IL1B at 6 h, and those of S100A8, S100A12, and LAP at 12 h. The intracellular S100A8 protein content doubled at 12-24 h but with little excretion into the medium. Regarding prostaglandin biosynthesis, PTGES mRNA was slightly higher after LPS exposure, whereas expression of the PGF synthase AKR1B1 was inhibited. Despite this, LPS treatment stimulated the secretion of both PGE₂ and PGF₂(alpha) to a similar extent. These results suggest that the family of S100 Ca²⁺ binding proteins are released from damaged endometrial cells and may play a major antimicrobial role. Prostaglandin synthesis increased during the uterine infection, but we found no evidence that this was associated with a change in the PGE:PGF ratio.

Clinical endometritis in an Argentinean herd of dairy cows: risk factors and reproductive efficiency

The objectives of this study were to assess the clinical and metabolic risk factors for clinical endometritis, the likelihood for having a normal vaginal discharge during postpartum, and the effects of endometritis on milk yield, reproductive efficiency, and metabolic status in Holstein cows. The study was conducted in a commercial dairy herd (Cordoba, Argentina) where 303 Holstein cows were enrolled. Cows were body condition scored (1 to 5) and tail bled on -14, 7, 21, 31, 41, and 50 d relative to parturition. Cows having a vaginal discharge with presence of pus between 21 and 41 d postpartum (dpp) were diagnosed as having clinical endometritis. Plasma blood samples were analyzed for nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and blood urea nitrogen using commercial kits and insulin-like growth factor 1, insulin, and leptin by RIA. Data were analyzed with PROC MIXED, PROC GENMOD, and PROC PHREG of SAS (SAS Institute Inc., Cary, NC). Abnormal calving and puerperal metritis increased the risk for endometritis [adjusted odds ratio (AOR)=2.21 for both]. High prepartum NEFA and high postpartum BHBA increased the risk for endometritis (AOR=1.003 and 1.001, respectively), whereas high prepartum blood urea nitrogen reduced it (AOR=0.853). Cut-offs of 456.6 μM NEFA and 402.5 μM BHBA had sensitivities of 0.69 and 0.58, and specificities of 0.88 and 0.86, respectively. The likelihood for having normal vaginal discharge increased with time (∼1% × dpp) and with normal calving. Cows with endometritis had higher milk yield than normal herdmates (27.8±0.9 vs. 25.7±0.4 kg/d), lower risk for pregnancy by 100 dpp (AOR=0.10), higher nonpregnancy risk by 200 dpp (AOR=2.87), and higher risk for culling than normal cows (AOR=2.28). Cows with endometritis had a lower hazard rate (0.44) for pregnancy and had approximately 70 d longer calving-to-conception intervals. Finally, endometritis had no effect on metabolic hormones. In conclusion, the risk for clinical endometritis increases with abnormal calving and puerperal metritis, as prepartum NEFA and postpartum BHBA concentrations increase. Prepartum NEFA and postpartum BHBA could be useful for the prediction of endometritis. Last, clinical endometritis has detrimental effects on reproductive efficiency, as affected cows take longer to get pregnant and are at higher risk for culling.

Short communication: Large-scale study on effects of metritis on reproduction in Danish Holstein cows

A total of 398,237 lactations of Danish Holstein dairy cows were studied with the main objective to investigate the effects of metritis on 2 fertility variables: interval from calving to first insemination (CFI) and nonreturn rate at 56 d after first insemination (NR56), adjusting for milk production and body condition score as confounders. Metritis was defined as a score of at least 5 (indicating purulent vaginal discharge with abnormal smell) on the Danish uterine score scale (from 0 to 9, used to evaluate vaginal discharge in the first 19 d postpartum on all fresh cows in herds participating in a national herd health program). Cows with metritis in early lactation presented a significant delay in first insemination (hazard ratio of 0.80) and a significantly reduced probability of success at first insemination. The effect of metritis was also present after adjusting for possible effects of body condition score, milk production in the first month of lactation, parity, herd, and year-season. Only a small part of the observed effect of metritis could be explained by variation in body condition score at calving and milk production in the first month after calving. The results from this large-scale study underscore the deleterious effects of metritis on the fertility variables CFI and NR56.

Comparison of a leukocyte esterase test with endometrial cytology for diagnosis of subclinical endometritis in postpartum dairy cows

The objective was to compare a leukocyte esterase (LE) test with endometrial cytology (EC) for diagnosis of subclinical endometritis in dairy cows. The relationship between subsequent fertility and the uterine (Ut) and cervical (Cx) leukocyte esterase activity was determined by the odds of pregnancy by 90 days in milk (DIM). Holstein cows (N = 218) without clinical endometritis and between 21 and 47 DIM from five commercial dairy herds were sampled for uterine and cervical leukocyte esterase activity and EC by cytobrush. To test the effect of time, cows were grouped into early (21-31 DIM) and late (32-47 DIM) animals. There was a slight agreement between UtLE and CxLE (weighted κ = 0.37). The percentage of neutrophils was correlated with esterase score either from the uterus (UtLE; P = 0.0001) or cervix (CxLE; P = 0.002). The percentage of neutrophils on EC (P < 0.001), the UtLE score (P < 0.0001), and the CxLE (P = 0.0009) diminished as DIM increased. Neither CxLE nor UtLE were statistically associated with pregnancy at 90 DIM. However, between 32 and 47 DIM, the percentage of neutrophils on EC and odds of pregnancy at 90 DIM were associated (P = 0.04). For the same interval, based on receiver/response operating characteristics analysis, the optimal cutoff was >6.7% neutrophils to classify cows with subclinical endometritis. In conclusion, uterine LE activity was correlated with percentage of neutrophils as determined by EC, but not with odds of pregnancy. Subclinical endometritis (>6.70% neutrophils) diagnosed by EC between 32 and 47 DIM was associated with reduced odds of pregnancy.