Evaluation of a systemic antibiotic treatment of toxic puerperal metritis in dairy cows

Effects of oxytocin and PGF2α on uterine contractility in cows with and without metritis-An in-vitro study

The aim of this study was to investigate the effects of PGF_2α and oxytocin in vitro on myometrial contractility in puerperal uteri. Thirteen puerperal uteri were removed and perfused after euthanasia of cows with (n=7) and without metritis (n=6). Measurement of uterine contractility was done using four piezoelectric crystals, which were implanted into the myometrium along the greater curvature of the uterine horn where fetal implantation occurred during the previous pregnancy. After 30min of equilibration, oxytocin (5 IU) or PGF_2α (2.5mg Dinoprost) was administered randomly into both uterine arteries, and 30min later, the second administration of either oxytocin or PGF_2α occurred. Treatment with oxytocin induced contractions in uteri with metritis and uteri without metritis (P<0.05). In uteri with metritis, greater uterine contractions occurred after stimulation with oxytocin than in uteri without metritis (P<0.05). Treatment with PGF_2α did not (P>0.05) result in increased contractions in the uteri without metrtitis, however, induced an initial decrease in contractions followed by an increase (P<0.05) in contractions in uteri with metritis. Myometrial and endometrial gene expression of PGF_2α (FPR) and oxytocin receptor (OTR) was greater (P<0.05) in uteri with metritis than in uteri without metritis. The results suggest that oxytocin, but not PGF_2α, is an effective uterotonic drug in puerperal cows. Uteri in which metritis was diagnosed contracted more strongly after treatment with oxytocin than uteri in which metritis was not diagnosed. This effect was paralleled by greater gene expression of OTR as well as FPR in uteri with metritis compared with uteri in which metritis was not diagnosed.

Minimum inhibitory concentrations of frequently used antibiotics against Escherichia coli and Trueperella pyogenes isolated from uteri of postpartum dairy cows

The objective of this study was to determine minimum inhibitory concentrations (MIC) of frequently used antimicrobials for Escherichia coli and Trueperella pyogenes isolated from postpartum bovine uteri of cows with acute puerperal metritis (APM, n = 67), cows suspected to have APM (n = 37), and healthy cows (n = 37) and to evaluate possible differences in MIC according to clinical signs. Cows with APM had reddish-brown, fetid vaginal discharge and rectal temperature (RT) ≥39.5°C within 21 d in milk; cows suspected to have APM had either reddish-brown, fetid vaginal discharge or RT ≥39.5°C within 21 d in milk; and healthy cows had neither fetid discharge nor RT ≥39.5°C. Samples were collected from cows on commercial dairy herds (n = 7) using the cytobrush technique. A total of 37 T. pyogenes isolates and 85 E. coli isolates were tested. Ceftiofur, a third-generation cephalosporin that is often used to treat APM, was the focus of analysis. Trueperella pyogenes and E. coli were isolated more often from samples of cows with APM (46 and 90%, respectively) compared with samples from healthy cows (19 and 54%, respectively). Regarding cows suspected to have APM, T. pyogenes and E. coli were numerically more often isolated (30 and 70%, respectively) than in healthy cows (19 and 54%, respectively). Minimum inhibitory concentrations of ceftiofur were low. For T. pyogenes and E. coli, MIC₅₀ (concentration that inhibited growth of 50% of isolates) were 0.25 and 0.5 µg/mL and MIC₉₀ (concentration that inhibited growth of 90% of isolates) were 0.5 and 1 µg/mL, respectively. Although ceftiofur inhibited all T. pyogenes at the highest concentration tested (64 µg/mL), the growth of 5.9% of E. coli was not impaired. Recently, ampicillin has been suggested as an alternative treatment for APM. Although the T. pyogenes isolates exhibited low MIC in general (MIC₅₀ ≤0.015 µg/mL and MIC₉₀ = 0.06 µg/mL) and 81.1% of all T. pyogenes could be inhibited at the lowest ampicillin concentration tested, 11.8% of the E. coli isolates were not impaired at the highest concentration (64 µg/mL) tested in this study. The MIC₅₀ and MIC₉₀ of E. coli were 4 and ≥128 µg/mL, respectively. We detected no difference in the MIC distributions of ceftiofur or ampicillin among isolates from the 3 APM groups. In summary, E. coli with high MIC against ceftiofur as well as against ampicillin were found in this study.

Antibiotic treatment of metritis in dairy cows-A meta-analysis

The objective of this meta-analysis was to assess the efficacy of the treatment of bovine metritis with common antibiotic and nonantibiotic treatment options. Acute puerperal metritis, a systemic and potentially painful illness with rectal temperature >39.5°C and signs of toxemia due to an infection of the uterus, occurs within 21 d after parturition. Because of the infectious nature, antibiotics are considered beneficial for the treatment of acute puerperal metritis. Each use of an antimicrobial drug, however, is associated with selective pressure for eventual emergence of resistant bacteria. The 23 trials evaluated in the course of a previously conducted systematic review were the basis for meta-analytic investigations. Selected trials were screened regarding their eligibility for the following investigations: (1) comparison of different antibiotic treatments with respect to metritis prevalence at time of re-examination, (2) efficacy of ceftiofur treatment with respect to metritis prevalence at time of re-examination, (3) comparison of efficacy of antibiotic versus nonantibiotic drugs with respect to metritis prevalence at time of re-examination, and (4) equivalence assessment of treatment effects on reproductive performance measures. Where at least 3 trials had investigated the same outcome variable and met the inclusion criteria (inclusion of a control or reference group diagnosed with metritis; reporting means and standard deviation in case of continuous data), meta-analytic investigations were carried out. Due to a shortage of comparable studies, we could not conduct investigations (1) and (3). Ceftiofur treatment of 828 metritic cows was associated with a decrease in the prevalence of metritis following treatment in comparison to 804 untreated cows. In conclusion, meta-analytic investigations uncovered a need for more high-quality studies. Furthermore, a positive effect of the most commonly used antibiotic drug, ceftiofur, for the treatment of bovine metritis could be shown. A comparison with other antibiotic or nonantibiotic treatment options could not be made.

Genetic and functional analysis of the bovine uterine microbiota. Part I: Metritis versus healthy cows

Metritis is a uterine disease that affects 10 to 30% of all lactating dairy cows and has detrimental effects on reproductive performance, milk production, and survival. Data regarding the identity and abundance of bacterial genes governing traits such as virulence, antibiotic resistance, and stress responses could enable identification of previously unknown agents that play a role in metritis pathogenesis. Moreover, such knowledge could lead to the development of improved treatments or preventive methods. Therefore, the objectives of this study were to characterize the uterine microbial population and to differentiate, for the first time, the microbial functional diversity in cows with metritis versus healthy cows. In addition, we aimed to identify relationships between microbial genes and postpartum uterine health. Uterine swabs were collected from 24 cows within 3 to 12 d in milk; 12 cows were diagnosed with metritis and the other 12 were healthy. Metritis was defined as a watery, reddish or brownish uterine discharge having a fetid smell, and rectal temperature greater than 39.5°C. Cows with a clear and viscous uterine discharge, not fetid or mucopurulent, were classified as healthy. Microbial metagenomic DNA from uterine swab samples was subjected to whole-genome shotgun sequencing on the Illumina MiSeq platform (Illumina Inc., San Diego, CA). The MG-RAST server (metagenomic rapid annotations using subsystems technology; http://metagenomics.anl.gov/) and STAMP software (http://kiwi.cs.dal.ca/Software/STAMP) were used to detect statistically significant differences in the abundance of taxonomic and functional features between the uterine microbial metagenomes of metritic and healthy cows. Our results showed an increased abundance of Fusobacteria and Bacteroidetes in metritic cows, confirming the potential role of those 2 taxa in the pathogenesis of metritis. The MG-RAST analysis revealed a significantly higher abundance of genes for protein transport across the cytoplasmic membrane and type VI bacterial secretion systems in the metritic microbiota. Additionally, genes coding for resistance to acid stress were exclusive to the metritis microbiota, suggesting that microbial resistance to acid stress is important for microbial survival in the infected uterus. On the other hand, genes coding for adhesion molecules, bacteriocins, and antibacterial peptides were significantly associated with the uterine microbiota of healthy cows, as was tolerance to colicin E2.

Estimating US dairy clinical disease costs with a stochastic simulation model

A farm-level stochastic model was used to estimate costs of 7 common clinical diseases in the United States: mastitis, lameness, metritis, retained placenta, left-displaced abomasum, ketosis, and hypocalcemia. The total disease costs were divided into 7 categories: veterinary and treatment, producer labor, milk loss, discarded milk, culling cost, extended days open, and on-farm death. A Monte Carlo simulation with 5,000 iterations was applied to the model to account for inherent system variation. Four types of market prices (milk, feed, slaughter, and replacement cow) and 3 herd-performance factors (rolling herd average, product of heat detection rate and conception rate, and age at first calving) were modeled stochastically. Sensitivity analyses were conducted to study the relationship between total disease costs and selected stochastic factors. In general, the disease costs in multiparous cows were greater than in primiparous cows. Left-displaced abomasum had the greatest estimated total costs in all parities ($432.48 in primiparous cows and $639.51 in multiparous cows). Cost category contributions varied for different diseases and parities. Milk production loss and treatment cost were the 2 greatest cost categories. The effect of market prices were consistent in all diseases and parities; higher milk and replacement prices increased total costs, whereas greater feed and slaughter prices decreased disease costs.

Management of Reproductive Disease in Dairy Cows

Postpartum diseases are common in dairy cows, and their incidence contributes to reduced fertility and increased risk of culling, making their prevention and management extremely important. Reproductive efficiency has a major impact on economic success of any dairy production unit. Optimizing reproductive efficiency contributes to overall efficiency of production units, minimizing environmental impacts and contributing to sustainability of food production. Additionally, control of reproductive diseases is important for maintenance of health and welfare of dairy cows; for minimizing use of antibiotics; and ensuring a wholesome, safe, and nutritious product.

A longitudinal cohort study of acute puerperal metritis cases in Swedish dairy cows

Background

Acute puerperal metritis affects cows during the early postpartum period and causes fever, fetid vaginal discharge and general depression. The disease is severe and treatment with antimicrobials is often required. This study followed 79 Swedish dairy cows with acute puerperal metritis with registered treatment and outcome in terms of recovery. Bacteria isolated from the uterus and their susceptibility to penicillin were studied. Clinical cases were assigned by participating practitioners who examined the cows, performed uterine swab sampling, decided treatment and provided information about cow health and calving conditions. Fertility and culling data were collected from the official Swedish milk and health recording scheme. Recovery from disease was defined in four levels; as a cow that survived 1 or 4 months, was inseminated and subsequently became pregnant. Intervals from dates of first and latest calving to insemination date were studied.

Results

The most common bacterial findings were a mixed culture of Escherichia coli and bacteria such as Gram positive cocci, Fusobacterium necrophorum, Clostridium spp. or Trueperella pyogenes. The Gram positive cocci, Pasteurella spp. and F. necrophorum were generally susceptible to penicillin. The majority of cows (70%) were treated with penicillin in accordance with the Swedish policy on treatment of metritis while 19% were treated with tetracycline and 8% were not treated with antimicrobials. Recovery rates were similar between treatments. Besides “calving to last insemination” interval (CLI) that was 5 days shorter than the national mean, fertility was slightly reduced compared to national means. “Calving to first insemination” interval (CFI) was 4 days longer than national mean and number of inseminations/cow increased from 1.9 to 2.1. Escherichia coli culture positive cows did not become pregnant to the same extent as cows without E. coli in the uterus (P = 0.046). Twin births resulted in a longer CFI (P = 0.034). The culling rate was generally high (42% within 300 days after occurrence of metritis), though death associated with acute disease was low (6%).

Conclusions

Escherichia coli was the most common bacterial pathogen isolated from cases of acute puerperal metritis in the present study. This bacterium is inherently resistant to penicillin, but although most cows were treated with penicillin, death due to acute disease was low and recovery and final fertility results were acceptable. In times of emerging antimicrobial resistance and demand for prudent antimicrobial use, we suggest that penicillin is a “good enough” choice if antimicrobial treatment of acute puerperal metritis is needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s13028-016-0257-9) contains supplementary material, which is available to authorized users.

A combination of lactic acid bacteria regulates Escherichia coli infection and inflammation of the bovine endometrium

Uterine function in cattle is compromised by bacterial contamination and inflammation after calving. The objective of this study was to select a combination of lactic acid bacteria (LAB) to decrease endometrium inflammation and Escherichia coli infection. Primary endometrial epithelial cells were cultured in vitro to select the most favorable LAB combination modulating basal tissue inflammation and E. coli infection. Supernatants were obtained to determine expression of pro-inflammatory cytokines, and E. coli infection was evaluated after harvesting the tissue and plate counting. The selected LAB combination was tested in uterus explants to assess its capacity to modulate basal and acute inflammation (associated with E. coli infection). The combination of Lactobacillus rhamnosus, Pediococcus acidilactici, and Lactobacillus reuteri at a ratio of 25:25:2, respectively, reduced E. coli infection in vitro with (89.77%) or without basal tissue inflammation (95.10%) compared with single LAB strains. Lactic acid bacteria treatment reduced CXCL8 and IL1B expression 4.7- and 2.2-fold, respectively, under acute inflammation. Ex vivo, the tested LAB combination reduced acute inflammation under E. coli infection, decreasing IL-8, IL-1β, and IL-6 up to 2.2-, 2.5-, and 2.2-fold, respectively. In the total inflammation model, the LAB combination decreased IL-8 1.6-fold and IL-6 1.2-fold. Ultrastructural evaluation of the tissue suggested no direct interaction between the LAB and E. coli, although pathological effects of E. coli in endometrial cells were greatly diminished or even reversed by the LAB combination. This study shows the promising potential of LAB probiotics for therapeutic use against endometrial inflammation and infection.

A study to examine the relationship between metritis severity and depletion of oxytetracycline in plasma and milk after intrauterine infusion

Metritis is a frequent problem in postpartum dairy cows. Intrauterine therapy with the antimicrobial oxytetracycline (OTC) is often used, although this therapy has not been shown to be superior to systemic therapy. The objectives of this study were to (1) determine the plasma and milk concentrations of OTC following intrauterine infusion in postpartum dairy cows with varying degrees of metritis severity; (2) determine the depletion time of OTC in an attempt to provide veterinarians withdrawal guidelines, should they use this therapy; and (3) correlate metritis severity scores with OTC concentrations in plasma and milk. Our hypothesis was that cows with more severe metritis would have higher OTC concentrations in milk following intrauterine therapy. Thirty-two cows were selected to participate in the study after farm personnel had determined that they had metritis based on evaluation of vaginal discharge between 4 and 14 DIM, in accordance with the farm's treatment protocols. Metritis scores (1-4) were assigned based on a published scheme: 1 represented yellow-to-orange thick discharge or translucent mucus with no fetid smell; 2 represented blood-tinged vaginal mucus, slightly watery, with little or no fetid smell; 3 represented red to red/brown watery discharge with moderate fetid smell; and 4 represented red to red/brown watery discharge containing pieces of placenta and an intense fetid smell. Trial cows received a single treatment of 4g of OTC (approximately 6.7mg/kg) via intrauterine infusion. Blood samples were collected over 96h, and milk samples were collected before intrauterine therapy and 3 times a day for 4 d following infusion. Following treatment, OTC rapidly diffused to plasma and subsequently to milk. Maximum OTC concentrations in plasma and milk occurred within the first 24h following intrauterine infusion, and 25 of the 32 cows had detectable OTC concentrations in milk at 4 d after intrauterine infusion. Cows with clinical metritis (metritis severity scores of 3 or 4) at the initiation of treatment were significantly and positively correlated with higher milk OTC concentrations at the second [time (T)9 h; r=0.43], fourth (T25 h; r=0.42), and fifth milking following treatment (T33 h; r=0.38) compared with cows with normal vaginal discharge. We also observed a positive correlation between initial metritis score and milk maximum concentration (r=0.36) and milk area under the concentration curve (r=0.36). Given that intrauterine administration of OTC is an extra-label therapy, dairy producers should consult with their veterinarian to ensure that milk is being tested at or below the established tolerance for OTC. This will ensure that violative drug residues do not enter the human food supply.

Relationship between Escherichia coli virulence factors and postpartum metritis in dairy cows

The objectives of this study were to report the prevalence of Escherichia coli and Trueperella pyogenes in the uterus of postpartum dairy cows before the onset of postpartum metritis (PPM) and to quantify their association with subsequent occurrence of PPM, to quantify the association between the presence of genes encoding E. coli virulence factors (VF) and PPM, and to determine the accuracy of using early postpartum uterine bacteriology results (bacteria and VF) to identify cows at risk of PPM. A prospective cohort study was conducted on 3 commercial dairy farms. Uterine swabs were collected from 371 Holstein dairy cows (3 commercial herds) at 1 to 7d in milk and submitted to the laboratory for identification of E. coli, T. pyogenes, and E. coli VF. A total of 40 VF were tested using the radioactive probe hybridization method. Postpartum metritis was defined as the presence of a fetid watery red-brown uterine discharge, associated with fever (rectal temperature >39.5°C), and systemic signs of illness (dullness, reduced appetite, and milk production). Surveillance of PPM was done by trained farmers blinded to laboratory results and cows were followed until 21d in milk. Statistical analyses were conducted using 2×2 tables and mixed logistical regression models. Prevalences of E. coli, T. pyogenes, and PPM were 42, 34, and 15%, respectively. A total of 32 VF were found in E. coli isolates. Most prevalent VF were extraintestinal pathogenic genes such as fimH (89%), hlyE (87%), and iss (70%). Cows positive for intrauterine E. coli were 3.2 times more likely to have subsequent PPM compared with bacteriologically negative cows. Cows with VF hra1 in their uterus were 2.7 times more likely to have PPM than cows positive for E. coli and negative for hra1 and 5.9 times more likely than bacteriologically negative cows. Cows with VF kpsMTII in their uterus were 3.2 times more likely to have PPM than cows positive for E. coli and negative for kpsMTII and 6.2 times more likely than bacteriologically negative cows. Using E. coli, hra1, and kpsMTII as predictors for subsequent PPM, positive predictive values were 23, 31, and 42%, respectively, whereas the negative predictive values were 91, 80, and 78%, respectively. Overall, these results showed that E. coli and some VF were associated with PPM.

Effect of puerperal metritis on reproductive and productive performance in dairy cows in Argentina

The objectives of this study were to evaluate the reproductive and productive performance of dairy cows with and without puerperal metritis and to evaluate the effectiveness of using a long-acting ceftiofur preparation. Dairy cows in one dairy farm, calving from July 2009 to January 2010, were examined between 3 and 14 days postpartum and classified on the basis of vaginal discharge into three groups: cows with normal discharge (control; C); cows with a bloody mucus purulent or pathologic nonfetid discharge (PnFD), and cows with bloody mucopurulent or purulent fetid discharge (PFD). Cows in C and PnFD groups were not treated, whereas those in the PFD group were randomly allocated to receive 2.2 mg/kg of ceftiofur subcutaneously behind the ear (PFD-T) or remain untreated (PFD-No T). From the 640 cows examined, 58.2% formed the C group, 13.4% formed the PnFD group, and 28.4% formed the PFD group. Survival curves differed between cows in the C group and PFD-No T group (P = 0.0013) and between PFD-No T versus PFD-T group (P = 0.0006). Survival curves of PnFD were intermediate and did not differ from those in the C group (P = 0.2) and PFD-T group (P = 0.1) but tended to be different from the PFD-No T group (P = 0.056). The postpartum interval to achieve a 25% pregnancy rate was 72 days for cows in the C group, 73 days for the PFD-T group, 83 days for PnFD group, and 95 days for the PFD-No T group. The chance of pregnancy in a cow in the C group was 1.98 times higher (95% confidence interval = 1.33, 3.08) and in cows in the PFD-T group was 2.16 times higher (95% confidence interval = 1.37, 3.50) than that in the PFD-No T group. Finally, the chance of pregnancy in cows in the PnFD group tended to be higher (P = 0.08) than that in the PFD-No T group but did not differ from the other two groups. Cumulative 305-day milk production was higher (P < 0.0001) in C group than those with vaginal discharge, regardless of fetidness and regardless of treatment. It is concluded that puerperal metritis affects the reproductive and productive performance of dairy cows and the treatment with ceftiofur was effective in reducing the adverse effects on reproductive performance but not on milk production.

Detection of genes encoding multidrug resistance and biofilm virulence factor in uterine pathogenic bacteria in postpartum dairy cows

Reckless use of antibiotics and/or development of biofilm are the rationale for the development of multidrug resistance (MDR) of pathogenic bacteria. The objective of the present study was to detect MDR genes in Trueperella pyogenes and to detect biofilm virulence factor (VF) genes in Escherichia coli isolated from the uterus of postpartum dairy cows. Uterine secretions from different parity postpartum Holstein cows (n = 40) were collected using cytobrush technique after a sterile procedure from cows with varying degree of uterine inflammatory conditions. The cytobrush was stored in a specimen collector, placed in a cooler with ice, and transported to the laboratory within 2 hours. The pathogens were isolated and were identified initially by their colony morphology and biochemical characteristics. To further identify and classify the single species, and to determine the presence of MDR and VF genes, the genes fragments were amplified using the respective primers by either singleplex or multiplex polymerase chain reaction protocol, and amplicons were detected by electrophoresis method. T pyogenes was isolated in 17 of 40 (42.5%) cows in the study population as recognized by the 16S rRNA gene. Of the positive T pyogenes samples, 8 of 17 (42.1%) were positive for integron type 1 (intI I), and none were positive for integron type 2 (intI II). Of those 8 positive for intI I, six of eight (66.7%) were positive for amplicons aadA5 and aadA24-ORF1 at 1048 and 1608 bp, respectively, associated with specific drug resistance. Presence of addA5 indicated resistance to sulfadiazine, bacitracin, florfenicol, and ceftiofur. Presence of addA24-ORF1 indicated resistant to sulfadiazine, bacitracin, penicillin, clindamycin, and erythromycin. E coli was isolated in 18 of 40 (45.0%) cows in the study population. The genes for VF, Agn43a, and Agn43 b, associated with biofilm production, were found in 6 of 18 (33.3%) of the positive isolates. Both T pyogenes MDR gene and E coli biofilm VF existed in more severe form of uterine diseases than subclinical endometritis. In conclusion, 35% of T pyogenes isolates found were positive for a gene cassette associated with antibiotic resistance, and 33% of the E coli isolates contained genes for the VF associated with biofilm production.

Minimum inhibitory concentrations of selected antimicrobials against Escherichia coli and Trueperella pyogenes of bovine uterine origin

Minimum inhibitory concentrations (MIC) of 9 antimicrobials for isolates of 2 common bovine intrauterine bacterial pathogens, Escherichia coli (n=209) and Trueperella pyogenes (n=35), were determined using broth microdilution methodology. The isolates were recovered from dairy cows from 7 herds postpartum using the cytobrush technique. The pathogens were initially identified using phenotypic techniques. Additionally, PCR was used to confirm the identity of T. pyogenes isolates and to categorize the E. coli isolates into phylogenetic groups A, B1, B2, and D. Minimum inhibitory concentrations in excess of published cut-points or bimodal distributions of MIC indicated potential antimicrobial resistance to ampicillin, cefuroxime, cephapirin, and oxytetracycline for E. coli, and to oxytetracycline for T. pyogenes. Of the antimicrobials tested, ticarcillin/clavulanic acid, ceftiofur, and enrofloxacin had the lowest MIC for these 2 pathogens. Differences in MIC of some antimicrobials were found between herds, age, breeds, and E. coli phylogenetic groups. Isolation of E. coli with an MIC ≥8μg/mL of oxytetracycline at 23d postpartum was associated with a lower probability of pregnancy within 6wk of commencement of breeding compared with those isolates with an MIC <8μg/mL (relative risk=0.66). Minimum inhibitory concentrations for uterine pathogens were determined for isolates from New Zealand dairy cows. However, in the absence of either epidemiological or clinical interpretive criteria, the interpretation of these MIC remains unclear. Further studies are required to define interpretative criteria, including determination of pharmacokinetic and pharmacodynamic profiles for antimicrobials.

Effect of intrauterine dextrose on reproductive performance of lactating dairy cows diagnosed with purulent vaginal discharge under certified organic management

The objectives of the study were to assess responses to treatments (clinical cure and resumption of estrous cycles) of cows with purulent vaginal discharge (PVD) that received intrauterine infusion of a hypertonic solution of 50% dextrose (DEX) or untreated control (CON) cows and the subsequent pregnancy per artificial insemination (PAI) in cows with and without PVD. Cows (n=2,852) from 2 dairy herds were screened for PVD using the gloved hand technique at exam 1 [26±3 d in milk (DIM)]. Cows with vaginal discharge scores of 2 or 3 (0-3 scale) were stratified by parity and randomly allocated into 1 of 2 treatment groups: (1) intrauterine infusion (~200 mL) of 50% DEX solution (n=456), or (2) untreated control animals (CON, n=491). Fourteen days posttherapy (40±3 DIM), cows with PVD were re-examined at exam 2 (40±3 DIM) to assess the response to treatments. All cows were subjected to the same reproductive program, which consisted of estrus detection twice daily (using tail chalking and visual observation) for the first 5 artificial inseminations; then, open lactating cows were turned out with bulls. Cows displaying signs of standing estrus underwent AI and no reproductive hormones were used. Pregnancy diagnosis (PD) was performed via transrectal palpation at 40±3 d post-AI. The risk of culling within 14 d posttherapy was not different among treatment groups. Cows with PVD had greater cervical diameter at exam 1 and decreased PAI compared with cows without PVD. Treatment with DEX increased the proportion of cows with clear vaginal discharge (clinical cure) and cyclicity 14 d posttherapy compared with CON cows. Pregnancy per AI for DEX (29.2±2%) cows was significantly greater than that for CON (22.5±2%) cows. Cows without PVD had a greater proportion of cycling cows (65.6%) and PAI (37%) with reduced pregnancy losses (5.7%) compared with DEX or CON cows. The use of intrauterine DEX alone improved reproductive performance of cows with PVD.

The effect of intrauterine infusion of dextrose on clinical endometritis cure rate and reproductive performance of dairy cows

The main objective of this study was to evaluate the intrauterine administration use of 200 mL of 50% dextrose solution as a treatment against clinical endometritis (CE); CE cure rate and reproductive performance were evaluated. Additionally, the association of several relevant risk factors, such as retained placenta (RP), metritis, CE, anovulation, hyperketonemia, and body condition score with reproductive performance, early embryonic mortality, and CE were evaluated. A total of 1,313 Holstein cows housed on 4 commercial dairy farms were enrolled in the study. At 7±3 DIM cows were examined for metritis and had blood collected to determine serum β-hydroxybutyrate concentration. To determine if cows had ovulated at least once before 44±3 DIM, the presence of a corpus luteum was evaluated by ovarian ultrasonography at 30±3 DIM and at 44±3 DIM. At 30±3 DIM, CE was diagnosed using the Metricheck device (SimcroTech, Hamilton, New Zealand); cows with purulent or mucopurulent vaginal discharge were diagnosed as having CE. Cows diagnosed with CE (n=175) were randomly allocated into 2 treatment groups: treatment (intrauterine infusion of 200 mL of 50% dextrose) or control (no infusion). Clinical endometritis cows were re-evaluated as described above at 44±3 DIM, and cows that were free of purulent or mucopurulent vaginal discharge were considered cured. Intrauterine infusion of dextrose tended to have a detrimental effect on CE cure rate, and treatment did not have an effect on first-service conception rate and early embryonic mortality. A multivariable Cox's proportional hazard model was performed to evaluate the effect of several variables on reproductive performance; the variables RP, CE, parity, anovulation, and the interaction term between parity and anovulation were associated with hazard of pregnancy. Cows that did not have RP or CE were more likely to conceive than cows that were diagnosed with RP or CE. Cows that had RP were at 3.36 times higher odds of losing their pregnancy than cows that did not have RP. In addition, cows diagnosed with CE were at 2.16 higher odds of losing their pregnancy than cows without CE. In conclusion, intrauterine infusion of 200 mL of 50% dextrose solution as a treatment for CE had a strong statistical tendency to decrease CE cure rate, did not improve first-service conception rate and early embryonic mortality, and did not decrease calving-to-conception interval.

Evidence for the use of ceftiofur for treatment of metritis in dairy cattle

Metritis is a cause of postparturient uterine disease in dairy cattle and is most commonly associated with watery fetid red-brown uterine discharge occurring in the first 21 days postpartum. The most severe form of metritis (puerperal metritis) often warrants antibiotic therapy. This article analyzes the current literature to determine the efficacy of ceftiofur in the treatment of metritis. Evidence-based review of the current literature suggests that there is evidence for the use of ceftiofur in the treatment of metritis. However, review of the literature also reveals the need for more studies with negative control groups.

Invited review: Antibiotic treatment of metritis in dairy cows: a systematic approach

Acute puerperal metritis (APM) is an acute systemic illness with fever ≥ 39.5 °C and signs of toxemia due to an infection of the uterus occurring within 21 d after parturition. Because of the infectious nature of APM, antibiotics are considered beneficial for its treatment. Each use of an antimicrobial drug, however, is associated with selective pressure for the emergence of resistant bacteria. Hence, there is a significant need to encourage prudent use of antibiotics and alternative therapies to antibiotics. Therefore, the objective of this study was to systematically review the current literature on treatment of APM. A comprehensive and systematic literature search was conducted utilizing the PubMed and CAB Abstracts databases to identify literature focusing on the antibiotic therapy of puerperal metritis in the cow. After application of specific exclusion criteria, 21 publications comprising 23 trials remained for final evaluation. Data extraction revealed that the majority of the studies (n = 19) were attributable to the highest evidence level. Of 21 studies controlled, 11 had an untreated group and 3 a positive control group. The majority of the studies (n = 17) applied ceftiofur for the treatment of APM. Concerning the efficacy of ceftiofur, 7 studies observed clinical improvement, whereas none found improved reproductive performance. Fewer than half of the studies (n = 10) performed a bacteriological examination and only 4 implemented an antibiotic susceptibility test. Also, 3 studies (13.0%) described a self-cure rate per se. Little attention was given to the issue of bacterial resistance (n = 3), the need for reducing the application of antibiotics (n = 2), or guidelines for prudent use of antibiotics (n = 1). Our findings demonstrate that implementation of bacteriological examinations, sensitivity testing, and determination of minimum inhibitory concentrations, as well as reporting and discussion of critical issues (e.g., self-cure rates, resistance, prudent drug use), were suboptimal. On the other hand, the quality of studies on the treatment of APM was good, as indicated by evidence level 1. Nevertheless, more high-quality research considering self-cure rates is necessary to address critical issues related to APM and crucial to the dairy industry, such as resistance, prudent use of antibiotics, animal welfare, and cost-benefit ratios.

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.

Body temperature in early postpartum dairy cows

A strategy widely adopted in the modern dairy industry is the introduction of postpartum health monitoring programs by trained farm personnel. Within these fresh cow protocols, various parameters (e.g., rectal temperature, attitude, milk production, uterine discharge, ketones) are evaluated during the first 5 to 14 days in milk (DIMs) to diagnose relevant diseases. It is well documented that 14% to 66% of healthy cows exhibit at least one temperature of 39.5 °C or greater within the first 10 DIM. Although widely adopted, data on diagnostic performance of body temperature (BT) measurement to diagnose infectious diseases (e.g., metritis, mastitis) are lacking. Therefore, the objective of this study was to identify possible factors associated with BT in postpartum dairy cows. A study was conducted on a commercial dairy farm including 251 cows. In a total of 217 cows, a vaginal temperature logger was inserted from DIM 2 to 10, whereas 34 cows did not receive a temperature logger as control. Temperature loggers measured vaginal temperature every 10 minutes. Rectal temperature was measured twice daily in all cows. On DIM 2, 5, and 10, cows underwent a clinical examination. Body temperature was influenced by various parameters. Primiparous cows had 0.2 °C higher BT than multiparous cows. Multiparous cows that calved during June and July had higher BT than those that calved in May. In primiparous cows, this effect was only evident from DIM 7 to 10. Furthermore, abnormal calving conditions (i.e., assisted calving, dead calf, retained placenta, twins) affected BT in cows. This effect was more pronounced in multiparous cows. Abnormal vaginal discharge did increase BT in primiparous and multiparous cows. Primiparous cows suffering from hyperketonemia (beta-hydroxybutyrat ≥ 1.4 mmol/L) had higher BT than those not affected. In multiparous cows, there was no association between hyperketonemia and BT. The results of this study clearly demonstrate that BT is influenced by various parameters in dairy cows. Therefore, these parameters have to be considered when interpreting measurements of BT in dairy cows. This information helps to explain the high incidence of type I and II errors when measuring BT and clearly illustrates that measures of BT should not be used as a single criterion to decide whether or not to provide antibiotic treatment to dairy cows. However, research-based test characteristics of other parameters (e.g., vaginal discharge) alone or in combination with BT are still lacking.

Diagnosis of acute puerperal metritis by electronic nose device analysis of vaginal discharge in dairy cows

The objective of this study was to estimate the diagnostic accuracy of an electronic nose device using vaginal discharge samples to diagnose acute puerperal metritis (APM) in dairy cows. Uterine fluid was sampled manually with a gloved hand and under sterile conditions for electronic nose device analysis (day in milk (DIM) 2, 5, and 10) and bacteriologic examination (DIM 5), respectively, and on additional days, if APM was diagnosed during the daily clinical examinations. A dataset containing samples from 70 cows was used to create a model and to validate the APM status predicted by this model, respectively. Half of the dataset (n = 35; 14 healthy and 21 metritic cows) was provided with information regarding the APM diagnosis and contained all three measurements (DIM 2, 5, and 10) for each cow and was used as a training set whereas the second half was blinded (n = 35; 14 healthy and 21 metritic cows) and contained only the samples collected on DIM 5 of each cow and was used to validate the created prediction model. A receiver operating characteristic curve was calculated using the prediction results of the validation test. The best observed sensitivity was 100% with specificity of 91.6% when using a threshold value of 0.3. The calculated P-value for the receiver operating characteristic curve was less than 0.01. Overall, Escherichia coli was isolated in eight of 28 (28.6%) and 22 of 42 (52.4%) samples collected from healthy and metritic cows, respectively. Trueperella pyogenes and Fusobacterium necrophorum were isolated in 14 and six of 28 (50.0% and 21.4%) and 17 and 16 of 42 (40.5% and 38.1%) samples collected from healthy and metritic cows, respectively. The prevalence of Escherichia coli and Trueperella pyogenes was similar in the samples obtained from metritic cows used for the training set and the validation test. The results are promising especially because of the objective nature of the measurements obtained by the electronic nose device.

Falsiporphyromonas endometrii gen. nov., sp. nov., isolated from the post-partum bovine uterus, and emended description of the genus Porphyromonas Shah and Collins 1988

Two black-pigmented, anaerobic bacterial strains, designated LMM 40T and LMM 41, were isolated from the bovine post-partum endometrium of two Holstein cows. The 16S rRNA gene sequences of the two strains were identical and showed the highest similarity to the 16S rRNA gene sequence of the type strain of Porphyromonas crevioricanis (90.2 %) but only 85.1 % 16S rRNA gene sequence similarity to the type strain of the type species of the genus Porphyromonas , Porphyromonas asaccharolytica . The major fatty acid profiles of the two strains were similar to those of species of the genus Porphyromonas , containing iso-C15 : 0 as the major component and moderate amounts of anteiso-C15 : 0, iso-C13 : 0, C15 : 0 and C16 : 0. Hydroxylated fatty acids, such as iso-C14 : 0 3-OH, iso-C16 : 0 3-OH and iso-C17 : 0 3-OH, were also detected. The quinone profiles were dominated by the menaquinones MK-8 and MK-9, while spermidine was the major polyamine. The polar lipid profiles contained major amounts of phosphatidylethanolamine, an unidentified phospholipid, an unidentified aminophospholipid and two unidentified lipids and minor amounts of phosphatidylglycerol, an unidentified aminolipid, a second unidentified aminophospholipid and an unidentified glycolipid. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The genomic DNA G+C contents of LMM 40T and LMM 41 were 40.7 and 41.3 mol%, respectively. Based on a polyphasic approach, including phylogenetic analysis, physiological and biochemical tests as well as metabolic fingerprinting, it is proposed that the two strains are members of a novel genus and species, for which the name Falsiporphyromonas endometrii gen. nov., sp. nov. is proposed. The type strain of Falsiporphyromonas endometrii is LMM 40T ( = DSM 27210T = CCUG 64267T). An emended description of the genus Porphyromonas is also presented.

Metritis in dairy cows: risk factors and reproductive performance

The objectives of this study were to assess the risk factors for metritis, its effects on milk yield and on reproductive performance, and the efficacy of ceftiofur therapy in Holstein dairy cows. Cows (n=303) from a commercial dairy herd in Argentina were studied. Cows were scored for body condition, and blood samples were collected on d -14, 7, 21, 31, 41, and 50 relative to parturition. Cows having a watery, purulent, or brown, and fetid vaginal discharge (VD) and rectal temperature ≤ 39.2°C were diagnosed as having clinical metritis, and those having a similar VD and rectal temperature >39.2°C were diagnosed as having puerperal metritis. Both clinical and puerperal metritis cows were randomly assigned to control (no treatment) or ceftiofur group (2.2mg/kg×3 consecutive days). Cure was declared if clear VD was observed at 21 d in milk (DIM). Blood samples were analyzed for nonesterified fatty acids, β-hydroxybutyrate, and blood urea nitrogen using commercial kits, and for insulin-like growth factor-1, insulin, and leptin by RIA. Data were analyzed with PROC MIXED, GENMOD, PHREG, and LIFETEST from SAS (SAS Institute Inc., Cary, NC). The risk for metritis increased with dystocia, retained fetal membranes, and dead calf [AOR (adjusted odds ratio)=2.58, 95% CI: 1.189-5.559], and as prepartum nonesterified fatty acids levels increased (AOR=1.001, 95% CI: 0.999-1.002). Conversely, risk decreased as prepartum insulin-like growth factor-1 increased (AOR=0.65, 95% CI: 0.349-1.219). Cows having either clinical or puerperal metritis produced less milk by 90 DIM than did healthy cows (2,236 ± 172 vs. 2,367 ± 77 vs. 2,647 ± 82 kg, respectively). Cows with puerperal metritis had lower risk for pregnancy by 100 DIM (AOR=0.189, 95% CI: 0.070-0.479) and a lower hazard rate for pregnancy by 150 DIM (hazard rate: 0.753, 95% CI: 0.621-0.911), and took longer to get pregnant (129 vs. 111 vs. 109 d, for puerperal metritis, clinical metritis, and healthy cows, respectively). Ceftiofur treatment was not associated with cure rate or milk yield but was related to increased risk for pregnancy at timed artificial insemination (AOR=2.688, 95% CI: 0.687-10.832), and for lower risk of reproductive cull (AOR=0.121, 95% CI: 0.014-1.066). In conclusion, abnormal calving and negative energy balance are associated with increased risk for metritis. Metritis, especially puerperal metritis, correlates with reduced milk production and poor reproductive performance. Finally, the likelihood for having a normal VD (indicative of cure) increased 2.6% for every day of increase in postpartum time and was 2 times higher for cows with clinical metritis than for those with puerperal metritis.

Agreement between rectal and vaginal temperature measured with temperature loggers in dairy cows

The overall objective of this study was to evaluate agreement between rectal (RT) and vaginal temperature (VT) measured with the same temperature loggers in dairy cows. Three experiments were conducted. The study began with a validation in vitro of 24 temperature loggers comparing them to a calibrated liquid-in-glass thermometer as a reference method. The association and agreement between the 24 temperature loggers with the reference method was r=0·996 (P<0·001) with a negligible coefficient of variance (0·005) between the loggers. In-vivo temperature loggers were tested in 11 healthy post-partum cows (Experiment 2) and 12 early post-partum cows with greater body temperature (Experiment 3). Temperature loggers were set to record VT and RT at 1-min intervals. To prevent rectal and vaginal straining and potential expulsion of temperature logger an epidural injection of 2·5 ml of 2% Procain was administered. Association between RT and VT was r=0·92 (P<0·001; Experiment 2) and r=0·94 (P<0·001; Experiment 3) with a negligible difference of −0·1 and 0·01 °C. Bland-Altman plots demonstrated agreement between RT and VT for healthy and early post-partum cows with greater body temperature in Experiments 2 and 3, respectively. Furthermore the intra-class correlation coefficient between RT and VT measured with identical loggers within cows of Experiments 2 and 3 also demonstrated greater agreements (P<0·001). Therefore, continuous VT monitoring with temperature loggers can be used as a measure of body temperature in dairy cows.

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.

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.

A critical evaluation of diagnostic methods used to identify dairy cows with acute post-partum metritis in the current literature

The overall objective of this study was to investigate how relevant research publications address the validity of diagnostic methods for acute puerperal metritis (APM) in dairy cows, a disease commonly treated with antibiotic drugs. Therefore, a literature search was conducted in Journal of Dairy Science, Theriogenology, Animal Reproduction Science and The Veterinary Journal utilizing the ScienceDirect database. The search revealed 259 articles addressing APM. After applying exclusion criteria, a total of 48 trials remained. It was determined whether the author gave a clear definition of APM, the time of diagnosis relative to calving, and the person who performed the diagnosis. Studies were checked for the presence of definitions of possible findings, thresholds, and test characteristics of the methods used. Overall 9 different diagnostic methods were employed. On average 2·5 ± 1·75 diagnostic methods were used in a study. References to support the use of the diagnostic methods were provided in 10 of 48 articles (20·8%). Vaginal discharge, transrectal palpation and rectal temperature were examined in 39, 22, and 21 of the studies, respectively. Thresholds for diagnostic tests and test characteristics were mentioned in 6 and 3 of the 48 articles, respectively. Based on this systematic review of 48 research papers the evidence supporting the use of the diagnostic methods to identify cows with APM has either been not reported or is weak. In conclusion, the reporting of the diagnostic methods to identify cows with APM needs to be improved and further high-quality research is necessary to improve diagnostic performance of the methods employed.

Treatment of dairy cows with PGF2α or NSAID, in combination with antibiotics, in cases of postpartum uterine inflammation

Background

The aim of the study was to test the effect of two treatments in cases of acute puerperal metritis (APM) and clinical metritis (CM).

Methods

Cows with APM and CM (n = 40)) were matched according to plasma fibrinogen levels (Fb) into three groups. Two negative control groups D (n = 11) and E (n = 17) were composed of healthy cows. The proportion of animals with APM and CM was similar within the groups. Treatment was started on the 3rd day postpartum (PP). In group A (n = 15), intramuscular (i.m.) administration of ceftiofur was used for five days in combination with flunixin for three days. Group B (n = 15) received i.m. administration of ceftiofur for five days followed by two injections of prostaglandin F2_α, with an interval of 8 h, on the 8th day PP. Group C (n = 10) served as a control group with no treatment. The general health status, body temperature (BT) and vaginal discharge were evaluated daily. Endometrial biopsies for bacteriology were taken once a week for seven weeks PP. Blood samples for the analysis of acute phase proteins were collected once a week for six weeks PP. Samples for progesterone analysis were taken twice a week for seven weeks PP. Fertility performance data were recorded.

Results

The area under the curve of BT was higher in group B than in group D cows (P < 0.05). No differences were found for vaginal discharge. There were no differences in bacterial growth, start of ovarian activity or serum amyloid-A or fibrinogen levels among the groups. The haptoglobin concentration was higher in the first and second weeks PP in group B compared with the other groups (P < 0.05). The number of days open was higher in group A than in both groups B and D (P < 0.05). The pregnancy rate after the first two services was higher (P < 0.05) in groups B and D than in groups A and C. The number of services per pregnancy was lower in group B than in group C (P < 0.05).

Conclusions

Regardless of more severe uterine inflammation found in animals from group B, these cows showed the same fertility parameters as healthy animals.

Effect of intrauterine dextrose or antibiotic therapy on reproductive performance of lactating dairy cows diagnosed with clinical endometritis

The objectives of this study were to assess the responses to treatments (clinical cure and cow survival 14 d posttherapy) of cows with clinical endometritis (CE) that received intrauterine infusion of a hypertonic solution of 50% dextrose (DEX) or subcutaneous ceftiofur crystalline free acid (CCFA) and subsequent pregnancy per artificial insemination (P/AI) in cows with CE compared with cows without CE. Cows (n=760) from 2 dairy herds were screened for CE using vaginoscopy and measurement of cervix diameters [exam 1; 26±3 d in milk (DIM)]. Cows with vaginal discharge scores of 2 or 3 (scale 0-3) were stratified by parity and randomly allocated into 1 of 3 treatment groups: (1) intrauterine infusion (∼200 mL) of 50% DEX solution (n=79); (2) 6.6 mg/kg single-dose of subcutaneous administration of CCFA (n=75); or (3) untreated control animals (CON, n=83). Fourteen days posttherapy (at 40±3 DIM), cows with CE were re-examined (exam 2; 40±3 DIM) to assess the response to treatments. All cows were presynchronized with 2 injections of PGF(2α) given 14 d apart (starting at 26±3 DIM) followed by Ovsynch (OV; GnRH-7 d-PGF-56 h-GnRH 16 h-timed-AI) 12 to 14 d later. Cows displaying signs of standing estrus any time during the protocol were inseminated, whereas the remaining cows were subjected to timed AI 16 h after the second GnRH of OV. Pregnancy diagnosis was performed via transrectal ultrasonography at 39±3d post-AI followed by pregnancy reconfirmation 30 d after the first pregnancy diagnosis. Uterine swabs revealed that Arcanobacterium pyogenes and Escherichia coli were the most predominant bacteria isolated at the time of treatments. Mortality within 14 d posttherapy was not different among treatment groups. Cows with CE had greater cervical diameter at exam 1 and decreased P/AI compared with cows without CE. Treatment with CCFA or DEX increased the proportion of cows with clear vaginal discharge (score 0; clinical cure) 14 d posttherapy compared with CON cows. Pregnancy per AI from DEX (29.8±4%) cows tended to differ from that of CON (21.1±4%) or CCFA cows (19.7±4%), but it resulted in similar P/AI as those cows without CE (39.1±2%). The use of intrauterine DEX alone or as an adjunct of antibiotic therapy for the treatment of CE needs further investigation.

Toll-like receptor 4 and MYD88-dependent signaling mechanisms of the innate immune system are essential for the response to lipopolysaccharide by epithelial and stromal cells of the bovine endometrium

Infection of the bovine endometrium with Gram-negative bacteria commonly causes uterine disease. Toll-like receptor 4 (TLR4) on cells of the immune system bind Gram-negative bacterial lipopolysaccharide (LPS), stimulating the secretion of the proinflammatory cytokines interleukin 1B (IL1B) and IL6, and the chemokine IL8. Because the endometrium is the first barrier to infection of the uterus, the signaling cascade triggered by LPS and the subsequent expression of inflammatory mediators were investigated in endometrial epithelial and stromal cells, and the key pathways identified using short interfering RNA (siRNA) and biochemical inhibitors. Treatment of endometrial cells with ultrapure LPS stimulated an inflammatory response characterized by increased IL1B, IL6, and IL8 mRNA expression, and IL6 protein accumulation in epithelial cells, and by increased IL1B and IL8 mRNA expression, and IL6 and IL8 protein accumulation in stromal cells. Treatment of endometrial cells with LPS also induced the degradation of IKB and the nuclear translocation of NFKB, as well as rapid phosphorylation of mitogen-activated protein kinase 3/1 (MAPK3/1) and MAPK14. Knockdown of TLR4 or its signaling adaptor molecule, myeloid differentiation factor 88 (MYD88), using siRNA reduced the inflammatory response to LPS in epithelial and stromal cells. Biochemical inhibition of MAPK3/1, but not JNK or MAPK14, reduced LPS-induced IL1B, IL6, and IL8 expression in endometrial cells. In conclusion, epithelial and stromal cells have an intrinsic role in innate immune surveillance in the endometrium, and in the case of LPS this recognition occurs via TLR4- and MYD88-dependent cell signaling pathways.

Factors associated with body temperature of healthy Holstein dairy cows during the first 10 days in milk

In this prospective observational study rectal and vaginal temperature of 82 (26 primiparous, 56 multiparous) early post-partum healthy dairy cows that calved without intervention within 3 months and did not show clinical signs of infectious and metabolic diseases were continuously measured and evaluated for associations with plausible factors during the first 10 days in milk (DIM). During May, June and July mean (±sd) temperature humidity index (THI) was 60·1±5; 66·8±5·6 and 74·2±4·3, respectively. Environmental conditions had a negligible effect on body temperature (BT) during May (P<0·05). During June and July, however, the ambient temperature and THI influenced BT (P<0·05). Furthermore, plausible factors like parity, DIM, months and time of day had an effect on BT (P<0·05). Overall, primiparous cows demonstrated 0·2°C greater BT during the first 10 DIM than multiparous cows. The effect of parity, however, on BT varied between DIM according to month (P<0·001). During this 3-month study period all cows demonstrated BT rhythms; however, the amplitude of BT increased from May to July (0·3 to 0·7°C). A greater proportion of the vaginal temperature measurements exceeded a threshold tested (⩾39·5°C) during July (46·8%) than in June (33·9%) and May (19·3%). Overall the percentage of BT values above a threshold of ⩾39·5°C was lower during the period 6.00–10.00 compared with the remaining 20 h (P<0·05). Therefore this study concluded that the BT of healthy post-partum dairy cows during the period 1–10 DIM post partum is greater compared with the reference range of 38·6 to 39·5°C reported by others and is influenced by parity, DIM, time of day and THI. When the association between BT and THI increased the reliability of threshold levels of BT (⩾39·5°C) decreased.