The effect of treatment of clinical endometritis on reproductive performance in dairy cows

Comparison between intrauterine application of an antibiotic and an herbal product to treat clinical endometritis in dairy cattle - A randomized multicentre field study

Uterine diseases are main indications for antibiotic use in dairy cows. To test a non-antibiotic treatment option, we compared the effect of an intrauterine cephapirin (Metricure®; cefapirin benzathin 500 mg per dosis; CEPH) with an intrauterine applied herbal product (25 ml of EucaComp® PlantaVet containing alcoholic extracts of Calendula officinalis L., Mellissa officinalis L., Origanum majorana L. and Eucalyptus globulus Labill. (EUC)) on the clinical cure of endometritis. Examinations of 816 cows between 21 and 35 days after calving were performed and cases of clinical endometritis (n = 169) were included. Diagnosis based on a scoring system for vaginal discharge. Study animals were randomly assigned to one of two treatment groups and treated immediately. After excluding animals with incomplete datasets, 136 cows (EUC: n = 61; CEPH: n = 75) remained for the final analysis. In total, 64% (EUC: 61%, CEPH: 67%) of analysed endometritis cases were considered as clinically cured 14 ± 2 days after the first treatment, 15% stayed uncured after the application of a maximum of two consecutive treatments, leading to an overall clinical cure rate of 85% (EUC: 82%, CEPH: 88%). No statistically difference in clinical cure rates could be observed between both treatment groups nor 14 ± 2 days after the first treatment (p = 0.956) neither regarding the overall cure rate (p = 0.923). In conclusion, the clinical cure of dairy cows' endometritis after the intrauterine application of the herbal product was non-inferior to the intrauterine application of the antibiotic cephapirin. These results could contribute to reduce the antimicrobial use in the daily veterinary routine treatment of endometritis.

Uterine microbial ecology and disease in cattle: A review

Due to the critical contribution of the uterine-associated microbiota in reproductive health, physiology, and performance, culture-independent methods have been increasingly employed to unravel key aspects of microbial ecology in the uterus of cattle. Nowadays, we know that bacterial diversity is crucial to maintain uterine health, however, there is still no consensus on the exact composition of a healthy uterine microbiota (or eubiosis). Generally, loss of bacterial diversity (or dysbiosis) contributes to the development of uterine infections, associated with increased relative abundances of Bacteroides, Fusobacterium, Trueperella, and Porphyromonas. Uterine infections are highly prevalent and gravely influence the profitability of cattle operations, animal welfare, and public health. Thus, understanding the dynamics of uterine microbial ecology is essential to develop effective strategies focused on preventing and mitigating the adverse effects of uterine dysbiosis as well as assisting in the process of restoring the core, healthy uterine microbiota. The aim of this review is to summarize research conducted in the microbial ecology of bovine uteri. We discuss the origin of the uterine microflora of healthy cows and the factors influencing its composition. In addition, we review the biology of specific pathogens that are known to increase in abundance during the occurrence of uterine disease. Lastly, we provide an overview of the bacterial biofilm in the bovine endometrium, and we briefly summarize the rationale for the use of probiotics to prevent uterine disease in cattle.

Review: Postpartum reproductive disease and fertility in dairy cows

This paper reviews recent data and concepts on metritis, purulent vaginal discharge (PVD), and endometritis in dairy cows and the ways in which these diseases affect reproductive performance. Metritis is characterized by fetid discharge from the uterus, with or without fever. Purulent vaginal discharge describes exudate that is >50% pus that may be attributable to uterine infection or cervicitis. Endometritis is inflammation of the uterus diagnosed by endometrial cytology with a proportion of neutrophils (typically ≥5%) that is associated with impaired fertility. Metritis and PVD are associated with uterine bacterial dysbiosis: changes in the microbiota to lesser diversity and greater abundance of pathogens, especially Gram-negative anaerobic bacteria, and Trueperella pyogenes in the case of PVD. Metritis is justifiably treated with approved antibiotics but criteria for more selective treatment without loss of performance are emerging. Purulent vaginal discharge is not synonymous with clinical endometritis, and greater precision in terminology is warranted. PVD is likely under-diagnosed and represents an opportunity for improved management in many herds. Endometritis seems in many cases to reflect persistent, dysregulated inflammation, for which the inciting cause is unclear. Postpartum uterine infection and inflammation have harmful effects on oocytes, embryo development, and the endometrium for at least three months, even if the disease is apparently resolved. Emerging concepts of the resolution and regulation of inflammation are promising for the improvement of prevention and therapy of endometritis.

In Vivo Efficacy of Echinops spinosus Decoction as a Therapeutic for Cows at Risk of Clinical Endometritis

Clinical endometritis (CE) is a multifactorial disease of dairy animals. Retained fetal membranes (RFM) and metritis are the major risk factors of CE in dairy cows. Because uterine inflammation affects the profitability of the dairy industry, antibiotics and hormonal therapies are commonly used to mitigate against the disease. However, the One-Health concept aims to reduce antibiotic use in food animals to avoid the emergence of drug resistance or residues in milk or meat. Thus, phytotherapy may represent a good alternative to antibiotics in food animals. Echinops spinosus (E. spinosus) is a natural plant known to have therapeutic, anti-inflammatory, antimicrobial, and wound-healing properties in vitro. The aim of the present study was to investigate the efficacy of E. spinosus as a preventive strategy for CE in dairy cows with other postpartum complications. Holstein−Friesian cows (n = 36) diagnosed with RFM or metritis enrolled in the study were allocated into three groups. One group received antibiotic treatment. Another group received prostaglandin injection (PG). The experimental group received E. spinosus decoction orally. As a control group, eutocic cows (n = 36), without RFM and metritis were included in the study. The efficiency of the treatment was based on the occurrence of CE and improved reproductive outcomes. At 30 ± 2 DPP, CE was diagnosed in 25%, 58.34%, and 75% in antibiotic, PG, and E. spinosus groups, respectively (p < 0.05). There were no differences between the groups at 55 ± 5 DPP (16.67%, 33.44%, and 41.67% in antibiotic, PG and E. spinosus groups, respectively, p > 0.05). The E. spinosus group had the longest open days, lowest conception rate at 150 DPP, and highest number of services per conception. Oral E. spinosus extract is ineffective as a therapeutic for cows at risk of CE. These findings may pave the way for future innovative strategies employing E. spinosus to protect cattle against endometritis.

A pilot study on bacterial isolates associated with purulent vaginal discharge in dairy cows in the south-west region of Western Australia

This study aimed to determine the bacterial isolates associated with postpartum endometritis among dairy cows in Western Australia and their antimicrobial susceptibility profiles. A cross‐sectional study was conducted between June–October 2020. Endometritis was defined as evidence of mucopurulent to purulent vaginal discharge 60–100 days postpartum. Vaginal discharge samples were obtained, cultured, identified and tested for antimicrobial susceptibility. A total of 118 bacterial isolates were grown from 46 animals, representing 36 species. The bacteria isolated from both aerobic and anaerobic cultures included Bacillus (60.2%), Streptococcus (12.7%), Trueperella (10.1%), Escherichia (6.7%) and Staphylococcus (5.9%). The remaining genera <5% were Histophilus, Aeroccocus, Enterococcus and Moraxella. Resistance was variable between isolates, but the highest resistance levels were observed in Streptococcal and Bacillus isolates to enrofloxacin, clindamycin and erythromycin, respectively. All Streptococcal isolates exhibited 100% resistance to enrofloxacin, and the greatest resistance levels were found in Streptococcus luteinises to trimethoprim‐sulfamethoxazole 83%, clindamycin 66% and 33% quinupristin‐dalfopristin. There was 84.5% resistance to clindamycin and 35.2% to erythromycin in the Bacillus isolates, with the highest resistance found in Bacillus licheniformis and Bacillus subtilis. Escherichia coli exhibited 12.5% resistance to gentamycin, ceftiofur, whereas amoxicillin‐clavulanic acid exhibited 37.5%. Within the Staphylococcal isolates, 28.5%, 28.5%, 42.8% and 14.2% resistance to ceftiofur, erythromycin, cefoxitin, penicillin and tetracycline were observed, respectively. The presence of resistance to important antimicrobials for human use, such as cephalosporins, macrolides and fluoroquinolones, highlights the need for judicious use of antimicrobials in dairy cattle.

Fertility Recovery in Cows with Clinical Endometritis

The article presents the materials of microbiological studies of the contents of the uterus of cows with acute catarrhal-purulent form of postpartum endometritis. Studies have shown that the microflora was represented by Proteus vulgaris, Escherichia coli, Staphylococcus aureus, Streptococcus faecium, Citrobacter freundii, Streptococcus pyogenes. The antibacterial activity of microflora to the drugs Enroflor®, Geomicini® F and Mitrec® was studied. The results of use of drugs for the clinical recovery of animals, the restoration of sexual cyclicity in cows were analyzed. The features of fertilization of cows after intrauterine use of various drugs for sexual cycles and for the entire duration of the experiment were studied. It was found that the highest therapeutic efficiency in the treatment of cows with acute catarrhal - purulent form of postpartum endometritis is provided by drug Mitrec®.

Validation of On-Farm Bacteriological Systems for Endometritis Diagnosis in Postpartum Dairy Cows

Simple Summary

Endometritis is a disease affecting reproductive performance in dairy cows. Considering the modern issues concerning the use of antibiotics in animal production, it is important to refine our criteria for diagnosing this disease. As such, confirming the presence of bacteria in the uterus before implementing an intrauterine antibiotic treatment is critical. To be able to achieve this on dairy farms, the accuracy of currently available on-farm bacteriological culture systems (Tri-plate and Petrifilm) needs to be validated. This study used data from 189 dairy cows to assess this objective. Uterine samples were collected on cows between 30 and 43 days in milk and were submitted for bacteriological culture using three different approaches: standard laboratory and two on-farm systems (Tri-plate and Petrifilm). Our results showed that the optimal criteria for using the Tri-plate and Petrifilm on-farm systems were >90 and >100 colonies, respectively, when compared with the results from the standard laboratory. These results support the possibility of using the Tri-plate on-farm bacteriological culture system to diagnose endometritis.

Abstract

The objective of this study was to validate the accuracy of the results of on-farm bacteriological culture media (Tri-plate and Petrifilm) from endometrial samples compared with the ones from the diagnostic laboratory. A cross-sectional observational study was set up within two dairy herd clients of the Université de Montréal. A total of 189 cows in the postpartum period were systematically enrolled to collect two uterine samples from cytobrushes during the same examination. The first cytobrush was used to inoculate the Tri-plate medium directly and then was sent to the reference laboratory for aerobic bacterial culture. The second cytobrush was used to make a microscopic smear for cytological analysis (proportion of polymorphonuclear cells) and subsequently diluted in 1 mL of saline to inoculate the Petrifilm medium. From these data, statistical analyses were computed to optimize the summation of sensitivity and specificity of the two systems compared with the results of the reference laboratory. For the Tri-plate and Petrifilm media, the cutoffs of ˃90 and ˃100 colonies gave the maximum sum of sensitivity and specificity, respectively. In conclusion, Tri-plate media was best at reproducing the results obtained by laboratory analysis using a threshold of >90 colonies.

Risk factors for purulent vaginal discharge and its association with reproductive performance of lactating Jersey cows

Despite the rapid growth in popularity of the Jersey breed, most research on dairy cows in the United States has been done with the Holstein breed. Postpartum uterine diseases negatively influence reproductive performance of dairy cows and limited data are available regarding predisposing factors for uterine diseases in Jersey cows. Our objectives were to determine the prevalence and risk factors for purulent vaginal discharge (PVD) and its effect on fertility of lactating Jersey cows. This was a retrospective observational study with data collected from 3,822 Jersey cows. The Metricheck device was used for PVD diagnosis, and positive cases (≥50% of pus in exudate) were further classified for severity using the following 4 categories based on the amount of pus observed: 50 to 60% pus in exudate, 60 to 90% pus in exudate, 90 to 100% pus in exudate, and 90 to 100% pus in exudate + uterine fluid detected by palpation per rectum. Univariable and multivariable regression analyzes were conducted to dissect the risk factors for PVD and severity of PVD in Jerseys cows. The major risk factors for PVD were calving-related problems, retained fetal membrane, metritis, and days in the close-up diet. A subgroup of cows (n = 740) was scored for body condition and locomotion scores and had blood sampled in the peripartum for determination of plasma concentrations of nonesterified fatty acids and β-hydroxybutyrate. In the multivariable analysis that considered data collected for the subgroup of cows, peripartum nonesterified fatty acids, postpartum β-hydroxybutyrate, and peripartum locomotion and body condition scores were not retained in the reduced model of predictors of PVD. Not surprisingly, pregnancy per artificial insemination following the first and second services was reduced in cows diagnosed with PVD compared with cows without PVD. In addition, PVD was associated with increased odds of pregnancy loss after the first service and reduced hazard of pregnancy by 305 d in milk. The stratification of PVD severity according to the amount of pus observed and the consistency of the uterus was meaningful, as observed by the differences in reproductive outcomes between cows with diverging amounts of pus in the retrieved exudate. Risk factors for PVD in Jersey cows was similar to previously reported for Holstein cows, and a strong detrimental effect of PVD on fertility was also observed in Jersey cows.

Using vaginal discharge score (VDS) grading system to evaluate the effect of clinical endometritis on reproductive performance of dairy cows in China

Clinical endometritis (CE) is a major cause in affecting the reproductive performance of dairy cows. The objectives of this study were to ascertain the prevalence of CE and to evaluate the effect of CE on reproductive performance in dairy cows using vaginal discharge score (VDS) grading system. 803 dairy cows were examined by vaginoscope with 4-point VDS at 26 ± 3 days in milk (DIM) and classified into six groups: non-endometritis with VDS 0 (control; CON), endometritis with VDS 1 (MEM), non-treated endometritis with VDS 2 (NTME), treated endometritis with VDS 2 (TME), non-treated endometritis with VDS 3 (NTPE), and treated endometritis with VDS 3 (TPE). Cows in TME and TPE groups were treated with 200 mL of 50% dextrose solution by intrauterine infusion. The prevalence of CE was 33% at 26 ± 3 DIM. Binary logistic regression analysis revealed cows in MEM, NTME and NTPE groups had a less likelihood of first artificial insemination (AI) pregnancy than those in CON group (P < 0.05). Kaplan-Meier survival curves for days open were statistically different (P = 0.004). In Cox regression model, cows in NTME and NTPE groups had a reduced pregnancy rate than those in CON group (P < 0.05). The hazard of pregnancy in NTME group was lower than that in TME group (P = 0.044). Similarly, it was lower for the hazard of pregnancy in NTPE group than in TPE group (P = 0.048). Cows in MEM, NTME, and NTPE groups required more services per pregnancy than those in CON group (P < 0.05). In conclusion, CE examined by the VDS grading system impaired reproductive performance, and mild endometritis with VDS 1 should be treated in the early postpartum period to ameliorate fertility in dairy herds.

MicroRNA-211 regulates the expression of TAB1 and inhibits the NF-κB signaling pathway in lipopolysaccharide-induced endometritis

Endometritis is a common postpartum inflammatory disease that endangers the reproductive health of humans and animals. Emerging evidence shows that microRNA is a new type of therapeutic molecule that plays a vital role in many diseases; however, its mechanism of action in lipopolysaccharide (LPS)-induced endometritis is still unclear. This study aims to investigate the regulatory role of miR-211 in the innate immune response involved in endometritis, and to evaluate its potential therapeutic value. Here, we found that the expression of miR-211 in bovine endometrial epithelial cells (bEECs) stimulated by lipopolysaccharide (LPS) was significantly reduced. Importantly, overexpression of miR-211 can significantly reduce the production of pro-inflammatory cytokines (IL-1β , IL-6 and TNF-α). In addition, we proved that TAB1 is the target gene of miR-211. MiR-211 inhibits TAB1 protein expression by binding to the 3'-UTR of TAB1 mRNA. Subsequently, we verified that the overexpression of miR-211 inhibited the activation of NF-κB p65 by targeting the TAB1-mediated pathway. Therefore, miR-211 has anti-inflammatory effects and mediates the negative regulation of the NF-κB signaling pathway in LPS-induced endometritis by targeting TAB1.

Effects of Intrauterine Infusion of a Chitosan Solution on Recovery and Subsequent Reproductive Performance of Early Postpartum Dairy Cows with Endometritis: A Pilot Field Trial

Simple Summary

Endometritis is one of the most common disorders during the postpartum period in dairy cows. We investigated the efficacy of intrauterine infusion of a chitosan solution in uterine recovery in early postpartum dairy cows with or without endometritis, and their subsequent reproductive performance. We found that, compared to the absence of treatment, chitosan solution treatment during the early postpartum period (approximately 3 weeks after parturition) accelerated uterine recovery after parturition of dairy cows. These findings suggest that the administration of chitosan solution once in the early postpartum period may have antimicrobial effects on the uterus. We suggest that chitosan solution is a potential therapeutic candidate for endometritis that may replace prostaglandin F_2α or antibiotic treatments_.

Abstract

This study investigated the efficacy of intrauterine infusion of a chitosan solution (CHT) on uterine recovery in early postpartum dairy cows with or without endometritis, and their subsequent reproductive performance. In Experiment 1, cows with endometritis at 3 weeks postpartum were administered CHT (n = 5) and prostaglandin F_2α (PGF_2α) (n = 4). Untreated cows (n = 7) served as the control group. In Experiment 2, 18 cows with a normally recovered uterus at the fresh cow check (mean, 35 days postpartum) were assigned to the CHT (n = 10) and control (n = 8) groups, and intrauterine infusion was conducted in the CHT group. Overall, in Experiment 1, the percentage of polymorphonuclear leukocytes significantly declined in the CHT group (32.3 ± 10.2 to 5.5 ± 2.4, p < 0.05) from week 3 to week 5, but no decline occurred in the PGF_2α and control groups. In Experiment 2, the CHT and control groups showed no significant differences in reproductive parameters, suggesting the absence of adverse effects of CHT on fertility. These results suggest that intrauterine infusion of CHT in the early postpartum period effectively accelerates uterine recovery from endometritis and might be a suitable replacement for PGF_2α administration.

Retention of placenta on physiological, hematological, biochemical and endocrinological profiles in crossbred cows under tropical island ecosystem

A study was carried out to assess the effect of retention of placenta (ROP) on hamatological, physiological, antioxidant and endocrinological profiles in crossbred cows under tropical island ecosystem of Andaman and Nicobar Islands. Each six number of cows was selected which were affected with ROP as group 2 and without ROP as group 1. These cows were in same parity in same locality with similar type management. Both the group of cows delivered healthy live calves normally and the cases were diagnosed as ROP when it failed to expel after 24 h of parturition. The ROP was removed manually as per standard procedure with aseptic measures. These affected cows were treated successfully and allowed to nurse the calves. Physiological profiles such as rectal temperature (RT), pulse rate (PR), respiratory rate (RR) and skin temperature (ST) were measured. Blood samples were collected, analysed for hematological profiles and serum separated, analysed the antioxidant profiles such as catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), total antioxidant capacity (TAC) and free radical such as malondialdehyde (MDA) and hormone profiles such as estradiol 17β (E2), progesterone (P4) and cortisol (CORT) were estimated. The result revealed that the crossbred cows of ANI with ROP suffered severe anaemia. The ROP affected animals were shown significantly low level of antioxidant profiles and higher MDA level than the unaffected animal groups. Similarly endocrinological profiles revealed the affected animals were having significantly higher level of CORT, P4 and lower level of E2 than unaffected crossbred cows. It was concluded that the ROP in the present study was due to anaemia, lack of antioxidants, over production of free radicals and disturbances of endocrinological profiles.

Short communication: Efficacy of a second intrauterine cephapirin infusion for the treatment of purulent vaginal discharge and endometritis in postpartum dairy cows

The objective of this study was to quantify the efficacy of a second intrauterine cephapirin treatment administered 14 d after the initial one on subsequent reproductive performance of postpartum dairy cows affected by purulent vaginal discharge (PVD) or endometritis (ENDO). In total, 4,140 Holstein cows from 30 commercial herds were enrolled in a randomized clinical trial. At 36 (±7) d in milk, cows were examined using the Metricheck device to diagnose PVD. An endometrial cytology sample was also collected from each cow to perform a leukocyte esterase test for diagnosing ENDO. Diagnosis of PVD and ENDO was done cow-side. Cows diagnosed with PVD or ENDO were assigned to receive 1 of 2 treatments: (1) a single intrauterine cephapirin infusion (500 mg of cephapirin benzathin; Metricure, Merck Animal Health, Kirkland, QC, Canada) at the time of initial examination or (2) a single intrauterine infusion at the time of initial examination and a second one 14 d later. Subsequent reproductive and culling events were collected until 200 d in milk. Statistical analyses were performed using univariable and multivariable mixed logistic regression models. In cows affected by PVD, a second intrauterine cephapirin infusion increased the pregnancy risk at first insemination in comparison with cows that only received one treatment (28.0 vs. 38.8%). In cows affected by ENDO, a second treatment also increased the pregnancy risk at first insemination compared with cows that only received one treatment (30.3 vs. 39.2%). Overall, these results demonstrate that administering a second intrauterine cephapirin infusion 14 d after the initial treatment in postpartum cows affected by PVD or ENDO did improve their subsequent reproductive performance.

Characterization of intrauterine cultivable aerobic microbiota at the time of insemination in dairy cows with and without mild endometritis

It is generally accepted that postpartum uterine infections decrease conception rates in dairy cows. Whereas clinical endometritis (CE) has been studied intensively, only little information about CE at the time of artificial insemination (AI) is available. The aim of this study was to characterize the intrauterine cultivable aerobic microbiota in healthy cows and in cows with mild CE at AI and to investigate its effect on the subsequent insemination success. The vaginal discharge score (VDS) of 120 Holstein Frisian dairy cows was assessed shortly after AI using the Metricheck device and pregnancy diagnosis was performed 39 days after AI. On average, cows received their second insemination (2.0 ± 1.2 standard deviation (SD)) and were 120.5 ± 40.2 days in milk. Intrauterine cytobrush samples were taken from cows with clear mucus (VDS 0, n = 58) and from cows with flecks of pus (VDS 1, n = 62), which was regarded as mild CE. Bacteria collected with the cytobrush were cultivated aerobically and identified by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). A total of 358 bacterial isolates were recovered, comprising 49 bacterial genera and 116 species. Bacillus, Staphylococcus, Corynebacterium and Streptococcus were the most prevalent genera with relative abundances of 19.6%, 14.2%, 10.1% and 8.1%, whereas common uterine pathogens, such as Trueperella pyogenes and Escherichia coli, were rarely detected. Bacillus spp. were more frequently detected in group VDS 0 (51.7%) than in VDS 1 (22.6%; P = 0.001) and there was a higher prevalence of Corynebacterium spp. in VDS 0 than in VDS 1 (37.9% vs 19.3%; P = 0.03). Cows with VDS 1 at the time of AI harbored neither Bacillus licheniformis nor Bacillus subtilis, while these species were detected in 27.6% and 8.6% of VDS 0 (P < 0.001 and P = 0.024 respectively). The insemination success in VDS 0 and 1 was 43.1 and 25.8% (P = 0.046). The diagnosis of mild CE at AI and the total bacterial load decreased the chance of pregnancy (P = 0.03) but no significant correlation between a distinctive bacterial species and insemination success was observed. In summary, cultivable uterine bacteria at AI presumably represent a part of the physiological microbiota, which is not directly linked to impaired fertility. These findings question intrauterine antimicrobial treatment shortly after AI and could represent the basis for the development of future treatment strategies.

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

Endometritis being a post-partum uterine infection in dairy cows is likely with substantial production loss through reduction in milk yield (MY), discarded milk during treatment and withdrawal period, and increased cost of veterinary treatment. This study quantified the influence of endometritis on MY of zero-grazed dairy cows managed on smallholder farms in Rwanda. The study enrolled a total of 461 cows within their 21 to 60 days in milk to examine for clinical endometritis (CLE) and subclinical endometritis (SCLE). A cow was considered having endometritis if it was positive for at least one test (CLE or SCLE), otherwise was negative. The MY data were collected prospectively from endometritis positive and negative cows for 30-day post-endometritis diagnosis. Compared to cows negative for endometritis, the positive endometritis cows were 2.4 times more (29.7 vs. 70.3%) with daily MY 15.3% lower (7.5 ± 0.2 vs. 8.9 ± 0.3 litres; p<0.05), representing a reduction of 1.4 ± 0.2 litres of milk/cow/day. Of the CLE positive cows, 33.4% (104/311) were treated using different veterinary drugs, which resulted in 23.5% more discarded milk compared (p<0.05) to untreated positive cows. Discarded milk was higher (p<0.05) among cows treated with oxytetracycline (65.9 ± 4.4 litres) compared to cows treated with procaine penicillin G and dihydrostreptomycin (35.5 ± 2.7 litres). The percentage of total milk loss was much higher (45.6%) among CLE positive cows that received treatment compared to the untreated cows (16.3%). These results demonstrate a strong association between MY loss and endometritis. A timely diagnosis and treatment of the disease is recommended using conventional veterinary drugs that have zero withholding time for milk to reduce the MY loss and associated economic loss, estimated at 154 US$ in a lactation.

Serum biochemical profile in buffalo endometritis and impact of treatment with PGF2α and intrauterine gentamicin infusion on postpartum reproductive performance

Improving reproductive performance of repeat breeder buffalo cows due to clinical endometritis is crucial in overcoming infertility problems in buffalo cows. The aim of the present study was to use PGF2α and/or gentamicin 10% for treatment of endometritis and to determine biochemical parameters in serum that could be used to diagnose endometritis in buffalo cows. A total of 64 anestrous buffalo cows were assigned into one of five treatment groups: group one (n = 9) buffalo cows were physiological normal cows and served as a control group; group 2 buffalo cows had endometritis, but were not treated (n = 10); group 3 buffalo cows had endometritis and were treated with intrauterine delivery of 100 ml of a 10% gentamicin sulfate solution in three times within 1 week (n = 15); group 4 buffalo cows received two I.M. doses of PGF2α (2 ml Estrumate IM) at the time of corpus luteum dominance (n = 15) (treatment 4 does not make sense as you stated that the cows were in anestrus) on the ovary; group 5 buffalo cows received two IM doses of PGF2α at an 11 day interval and the 10% gentamicin solution as described for group 3. Serum samples were collected from control, pre-treated, and post-treated buffalo cows with endometritis to evaluate the diagnostic biochemical parameters. The days to first estrus (DFE), number of services per conception (S/C), days open (DO), and pregnancy rate (Preg) were the measures for determining reproductive performance for the buffalo cows. The buffalo cows treated by gentamicin and PGF2 exhibited their first estrus earlier than cows in the other four groups of cows. The number of days open for control cows was greater (P < 0.05) than for the other groups and the control cows, as were the number of services per conception (P < 0.05) and pregnancy rate (30%: P < 0.05). The receiver operating characteristic (ROC) curve was used to identify biochemical parameters in serum to predict endometritis. Creatine kinase (CK), aspartate aminotransferase (AST), and concentrations of total bilirubin and immunoglobulins in serum were greater (P < 0.05), while serum albumin values were lower (P < 0.05) in serum of buffalo cows with endometritis. From the ROC analyses, CK was the most predictable biomarker for endometritis with an area under the curve of 0.889, sensitivity of 80%, and specificity of 100% (P < 0.001). In conclusion, the use of gentamicin and PGF2 for treatment of endometritis improves the reproductive performance of buffalo cows, and concentrations of CK serve as an aid for diagnosing endometritis.Graphical abstract.

Field trial on the post-insemination intrauterine treatment of dairy cows with mild endometritis with cephapirin

Cows in estrus but with signs of clinical endometritis (CE) are often not inseminated or undergo an intrauterine treatment after artificial insemination (AI). Decades ago, the so-called Aström method was described as intrauterine infusion of iodine-potassium solution 2-4 days after AI. Nowadays, it is common to use antibiotics instead of iodine solution and the treatment is performed only a few hours after AI. Although widespread in practice, there is only little information about the efficacy of this treatment. Thus, this study evaluated the effect of a post-breeding intrauterine treatment with cephapirin on insemination success in cows with signs of mild CE. In total, 281 cows subjected to an Ovsynch program with fixed-time AI and examined for vaginal discharge straight after AI by use of the Metricheck device were included. Cows with cloudy discharge or flecks of pus in the mucus were assigned to a treatment or a control group. The treatment group (MET; n = 87) received 6 ± 1 h after AI an intrauterine treatment with 500 mg of cephapirin (Metricure, Intervet Deutschland GmbH). Control cows (CON; n = 91) remained untreated. Animals with clear discharge were assigned to a healthy comparison group (HE; n = 103). Pregnancy diagnosis was performed 39 days after AI. The proportion of pregnant cows after the AI directly preceding the enrollment did not differ significantly (P > 0.05) between HE (35.0%), CON (27.5%) and MET (32.2%). Cephapirin treatment had also no positive effect on other reproductive performance measures, i.e, the percentage of pregnant cows 200 days after enrollment (HE: 64.1%, CON: 73.6%, and MET: 73.6%) or the mean interval from enrollment to conception (HE: 25.4 days, CON: 30.0 days, and MET: 29.7 days). The binary logistic regression showed that the only risk factors with a detrimental effect on fertility were a history of CE 28-34 days postpartum and season. Although cows in MET and HE were 1.74 and 1.37 times more likely to conceive after AI than CON, this effect was not significant. Uterine sampling of a subset of cows with CE (n = 50) revealed 127 bacterial isolates. The most frequently found genera were Staphylococcus (19.7%), Bacillus (12.6%), Streptococcus (10.2%), Corynebacterium (8.7%), and Lysinibacillus (7.9%). The finding that common uterine pathogenic bacteria were rarely detected additionally questions an intrauterine antibiotic treatment of cows with mild CE at AI.

Selected leukocyte subpopulations in peripheral blood and uterine washings in cows before and after intrauterine administration of cefapirin and methisoprinol

The aim of the study was to evaluate the selected lymphocyte subpopulations TCD4, TCD8, BCD21, BCD25, CD18, CD11b, and MHC II in blood and uterine flush of cows with endometritis, before and after intrauterine (i.u.) administration of cefapirin and methisoprinol. The research was carried out on 28 cows with clinical endometritis. Animals were divided into four groups, each composed of seven cows, depending on the i.u. preparation used: Group A, cefapirin; Group B, methisoprinol; Group C, cefapirin and methisoprinol simultaneously; and a control group-without medication. The study was performed using flow cytometry method. Summarizing the results of the research, i.u. infusion of cefapirin caused a weakening of the effector phase of the local uterine immune response; however, it enhanced leukocyte chemotaxis and antigen presentation. After i.u. administration of methisoprinol, the stimulation of specific uterine immunity mechanisms was mainly observed. The use of both mentioned preparations showed the strengthening of specific uterine immunological mechanisms presumably caused by methisoprinol, despite the inhibitory effect of the antibiotic. Intrauterine use of immunostimulatory substances can improve the effectiveness of the endometritis treatment in cows by improving specific local mechanisms of uterine immunity. As a consequence, it may enhance the effector function of immune competent cells and finally eliminate inflammation.

Symposium review: The uterine microbiome associated with the development of uterine disease in dairy cows

Until 2010, our knowledge of the uterine microbiome in cows that developed uterine disease relied almost exclusively on culture-dependent studies and mostly included cows with clinical endometritis (i.e., with purulent uterine discharge). Those studies consistently found a strong positive correlation between Trueperella pyogenes and clinical endometritis, whereas other pathogens such as Escherichia coli, Fusobacterium necrophorum, Prevotella melaninogenica, and Bacteroides spp. were also commonly cocultured. In contrast, Streptococcus spp., Staphylococcus spp., and Bacillus spp. were usually isolated from healthy cows. Starting in 2010, culture-independent studies using PCR explored the microbiome of cows with metritis and clinical endometritis, and observed that E. coli was a pioneer pathogen that predisposed cows to infection with F. necrophorum, which was strongly associated with metritis, and to infection with T. pyogenes, which was strongly associated with clinical endometritis. Starting in 2011, culture-independent studies using metagenomic sequencing expanded our knowledge of the uterine microbiome. It has been shown that cows have bacteria in the uterus even before calving, they have an established uterine microbiome within 20 min of calving, and that the microbiome structure is identical between cows that develop metritis and healthy cows until 2 d postpartum, after which the bacterial structure of cows that developed metritis deviates in favor of greater relative abundance of Bacteroidetes and Fusobacteria and lesser relative abundance of Proteobacteria and Tenericutes. The shift in the uterine microbiome in cows that develop metritis is characterized by a loss of heterogeneity and a decrease in bacterial richness. At the genus level, Bacteroides, Porphyromonas, and Fusobacterium have the strongest association with metritis. At the species level, we observed that Bacteroides pyogenes, Porphyromonas levii, and Helcococcus ovis were potential emerging uterine pathogens. Finally, we have shown that the hematogenous route is a viable route of uterine infection with uterine pathogens. Herein, we propose that metritis is associated with a dysbiosis of the uterine microbiota characterized by decreased richness, and an increase in Bacteroidetes and Fusobacteria, particularly Bacteroides, Porphyromonas, and Fusobacterium.

Effects of hypertonic dextrose and paraffin solution as non-antibiotic treatments of clinical endometritis on reproductive performance of high producing dairy cows

The objective of this study was to compare the reproductive performance of cows affected by clinical endometritis (CE) following treatment with an intrauterine infusion of 50% dextrose solutions (DEX) and liquid paraffin (LP) as alternative therapies with routine treatments including PGF2α injection and intrauterine infusion of oxytetracycline (OTC). Moreover, the reproductive indices of cows treated with endometritis were compared with those of healthy ones. At postpartum reproductive tract examination (28-35 DIM) in one Iranian dairy farm, cows with CE without any selection were assigned to four groups: (a) OTC, a common treatment in Iran, was administered (5 g) to 396 cows, (b) PGF2 α (PG) was injected to 496 cows, (c) dextrose solution (DEX): intrauterine infusion of 50% dextrose solution (200 ml) was done in 427 cows, and (d) liquid paraffin (LP) was administered (100 ml) to 423 cows via intrauterine route. We further assigned 2,233 clinically healthy cows to the control group. The incidence of endometritis was 41.6% in this study. Based on the results of reproductive indices including median days to first AI, days open (DO), first service conception rate, conception rate in 2nd and 3rd services, conception rate in all three services, pregnancy rate < 100 days and pregnancy rate < 200 days, except for median days to first AI in other reproductive indexes, reproductive performance was significantly lower in LP group compared with the healthy cows and other treatment groups (p < 0.05). Except for the first service conception rate and proportion of cows pregnant before 100 days in milk (DIM), there existed no significant difference between the DEX group and the control as far as reproductive performance is concerned (p ≥ 0.05). The first service conception rate was recognizably lower in DEX group compared with OTC and PG (p < 0.05). In conclusion, the use of a non-antibiotic special solution of dextrose 50% is a good alternative to antibiotic agents concerning the treatment of CE in dairy cows.

Short communication: Proinflammatory gene expression relative to the collection technique of endometrial samples from cows with and without subclinical endometritis

Uterine inflammation negatively affects reproductive performance and is an important cause of infertility and subfertility in dairy cows. Several studies have investigated the use of gene expression in endometrial samples collected by biopsy or cytology to evaluate the inflammatory response of the cow uterus. This study aimed to compare the expression of the CCL5, CXCL8, IL6, and IL1B genes in the bovine endometrium according to the site of sample collection [caruncular (C) or intercaruncular (IC)], the collection method (biopsy or cytology), and the category of inflammation based on endometrial cytology (zero, medium, or high) in subclinical endometritis. The reproductive tracts of dairy cows were collected from a slaughterhouse, and punch-biopsy samples of endometrial tissues were obtained from both regions (C and IC). Endometrial cells from these regions were collected with the cytobrush technique and then used for the analysis of mRNA expression by quantitative PCR. After counting polymorphonuclear cells (PMN) by endometrial cytology, 20 uteri with an ovary at stage I (d 1-4 of estrous cycle) were categorized into 3 groups. Uteri with 0% PMN (n = 10) were assigned to group zero, uteri with 5 to 15% PMN (n = 5) to group medium (12.2 ± 1.6% PMN), and uteri with >15% PMN (n = 5) to group high (53.8 ± 32.9% PMN). All data were analyzed with 2-way ANOVA with Bonferroni multiple comparison post test. The results from gene transcripts demonstrated that the region (C or IC) of the endometrial biopsy had no influence on any of the degrees of inflammatory reaction observed. However, gene expression was more elevated in the endometrium of cows with greater inflammation compared with those without inflammation (CCL5, CXCL8, IL6, IL1B) and those with medium inflammation (CCL5, IL6). Expression of the genes evaluated did not differ between the endometrium without inflammation and with medium inflammation. However, in the high inflammation group, all genes were comparatively more expressed in samples collected by cytology relative to those derived from biopsies for both anatomical regions. In conclusion, gene expression did not differ between the C and IC tissue. Samples collected from animals with greater inflammation had greater gene expression than those with zero or medium inflammation. In addition, cytology samples had greater gene expression than biopsy samples in the high inflammation group.

Randomized clinical trial to evaluate the efficacy of prostaglandin F2α to treat purulent vaginal discharge in lactating dairy cows

The objectives of this study were (1) to assess the effect of purulent vaginal discharge (PVD) on reproductive performance using a 4-point vaginal discharge score (VDS) and (2) to evaluate the effect of PGF2α treatment in cows with PVD on reproductive performance. Holstein cows (n = 2,473) from 1 commercial dairy farm had their vaginal discharge scored at 32 ± 3 d in milk (DIM) using a 4-point scale. Cows were also scored for body condition score and had their ovaries examined using transrectal ultrasound. A VDS-2 or greater was used to define PVD. Cows with PVD were assigned to receive 2 doses of 500 µg of PGF2α analogue (n = 277; Cloprostenol; PGF Veyx forte, Veyx Pharma Ltd., Schwarzenborn, Germany) 14 d apart (odd ear tag number) or remained untreated (n = 272; even ear tag number). All cows not detected in estrus at 90 ± 3 DIM were enrolled into a timed artificial insemination (AI) protocol. The effect of VDS and the effect of PGF2α in cows with PVD on reproductive performance were evaluated separately. First service conception risk (FSCR), time to first AI, and time to pregnancy were used as indicators for reproductive performance. Data were analyzed with Cox's regression and mixed logistic models. The prevalence of PVD was 22.2% (548/2,473). We detected an interaction of parity and VDS for FSCR and time to pregnancy. In primiparous cows, VDS had no effect on FSCR and time to pregnancy. In multiparous cows, VDS had an effect on FSCR and time to pregnancy. Multiparous cows having a VDS-2 or a VDS-3 had decreased odds of pregnancy at first AI compared with cows having a VDS-0. Multiparous cows with VDS-1 or VDS-3 had a decreased hazard of conceiving within 200 DIM. The treatment effect of PGF2α was conditional on parity. In primiparous animals with PVD without a corpus luteum present at 32 DIM, treatment with PGF2α reduced FSCR. Irrespective of the presence of a corpus luteum, treatment with PGF2α decreased the hazard of conceiving within 200 DIM in primiparous cows. Although multiparous cows with PVD treated with PGF2α had increased odds of pregnancy at first AI, no treatment effect was observed on the hazard of conceiving within 200 DIM. Our results do not support the blanket use of PGF2α as a treatment option in postpartum dairy cows having PVD.

Tolerance and Innate Immunity Shape the Development of Postpartum Uterine Disease and the Impact of Endometritis in Dairy Cattle

Bacteria are ubiquitous in the bovine uterus after parturition, but 50 years ago, cows tolerated these bacteria and few animals developed uterine disease. Now, up to 40% of dairy cattle develop postpartum uterine disease. Uterine disease causes infertility by compromising the function of not only the endometrium but also the ovary. Animals defend themselves against pathogens using tolerance and resistance mechanisms. Tolerance is the ability to limit the disease severity induced by a given pathogen burden. Resistance is the ability to limit the pathogen burden and is usually the function of immunity. Endometrial cells contribute to tolerance and have roles in innate immunity and the inflammatory response to pathogens. However, failures in endometrial tolerance and the character of the inflammatory response shape postpartum uterine disease. We propose that uterine health is more dependent on the ability of the endometrium to tolerate pathogens than the ability to resist invading bacteria.

Effect of carbetocin, oxytocin and prostaglandin E2 and F2α on intrauterine pressure in cows in dioestrus and oestrus

Objective: To describe the physiological activity of the myometrium in oestrus and dioestrus and the induced activity after medication in cows with particular reference to segmental differences. Material and methods: Six cows were given the pharmaceuticals carbetocin, oxytocin and prostaglandin (PG) F2α (dinoprost) intramuscularly and PGE2 intravenously. The physiological myometrial activity was recorded for 15 minutes and the induced activity for 105 minutes by using a transcervically attached pressure probe containing six pressure micro-transducers. Results: Lower pressures were measured in dioestrus com pared to oestrus before (dioestrus 3.2 ± 8.88 mmHg, oestrus 12.4 ± 13.23 mmHg, p < 0.0001) and after the drug administration. Carbetocin provoked the longest lasting effect (60 minutes in dioestrus, 75 minutes in oestrus) followed by PGE2 (45 minutes in dioestrus, 60 minutes in oestrus), PGF2α (30 minutes each) and oxytocin (15 minutes in oestrus only). In contrast to the other drugs carbetocin did not cause any pressure decrease beneath the base level after the primary pressure increase in dioestrus. In dioestrus the pressure before drug administration was significantly higher in the cervix (3.6 ± 19.40 mmHg) and the uterine body (7.1 ± 36.10 mmHg) than in the uterine horn (1.1 ± 7.21 mmHg). Conversely, in oestrus the pressure in the uterine horn (16.6 ± 17.73 mmHg) was significantly higher than in the uterine body (6.2 ± 16.59 mmHg) and the cervix (10.4 ± 17.91 mmHg). Drug administration in dioestrus caused a cornual pressure increase and the pressure in the uterine body decreased, whereas in oestrus the pressure increased in all uterine segments. The physiological frequency of the pressure waves in dioestrus was 5.2 ± 3.02 in 15 minutes compared to 7.5 ± 2.89 in 15 minutes in oestrus. No traceable changes of the contraction frequency were found after medication. Conclusion and clinical relevance: Carbetocin caused the most enduring increase in intrauterine pressure in dioestrus and oestrus and may therefore be indicated best for therapeutic use. The tested drugs had the same effects on the various uterine segments and no effect on the contraction frequency.

A method for the isolation and enrichment of purified bovine milk exosomes

Exosomes are nanovesicles that play important roles in intercellular communication as they carry information to target cells. Isolation of high purity exosomes will aid in studying the exosomal cargo and quantity as well as how cell-specific messages are carried. We describe a new method incorporating size exclusion chromatography (SEC) to enrich milk-derived exosomes from extracellular vesicles (EVs). This involved the initial isolation of EVs from bovine milk via milk processing and ultracentrifugation; followed by a new method to enrich exosomes using SEC. This method was compared to buoyant density gradient centrifugation, a widely used method of enrichment. Exosomes were characterised by particle concentration and size (nanoparticle tracking analysis, NTA), morphology (transmission electron microscopy, TEM), presence of exosomal markers (immunoblotting) and protein concentration (bicinchoninic acid assay, BCA). Proteomic profiles of exosomal fractions were analyzed by mass spectrometry using Information Dependant Acquisition. Milk exosomal fractions were shown to contain exosomal markers flotillin-1 (FLOT-1) and tumor susceptibility gene-101 (TSG-101). The new method produced a higher yield of exosomes compared to buoyant density gradient centrifugation. Pooled exosomal fractions exhibited intact morphology by TEM. The use of SEC confirmed the fractionation of exosomes based on size while minimizing the interference with proteins. Tetraspanins CD9 and CD81 were observed via mass spectrometry in exosomal fractions. This new and efficient method confirmed the signatures for exosomes derived from unpasteurized bovine milk. Purification of exosomes is a foundational technique in the study of biomarkers for pathological conditions and effective drug delivery systems.

Effect of diagnosis and treatment of clinical endometritis based on vaginal discharge score grading system in postpartum Holstein cows

In this study, the prevalence, effectiveness of diagnosis, and treatment based on vaginal discharge score (VDS) of clinical endometritis in cattle were evaluated. To detect clinical endometritis and classify its severity, vaginoscopy was performed during 21 to 60 days postpartum in 164 Holstein cows consisting of 229 lactations. Groups were defined using the 4-point VDS scale. Study groups included the following: non-endometritis (VDS=0; no/clear mucus; NEM group; n=168); mild endometritis, no treatment (VDS=1; mucus containing flecks of white/off-white pus; NTR group; n=30); and severe endometritis, treated with PGF2α (VDS≥2; discharge containing <50% pus; and VDS=3; discharge containing >50% pus, and fluid or uterine horn asymmetry; TEM group; n=31). Cows treated with PGF2α that did not recover (VDS≥1, n=5) received intrauterine procaine penicillin and streptomycin. Prevalence of clinical endometritis (VDS≥1) was 26.6%. The NTR group required significantly more artificial inseminations per pregnancy than NEM and TEM groups (2.8 ± 1.8 vs 2.0 ± 1.3, 1.9 ± 0.8, P<0.05). In survival analysis, the proportion of non-pregnant cows was higher in the NTR group compared to the NEM (P=0.012) and TEM (P=0.076) groups. In the TEM group, calving to first artificial insemination interval tended to be higher in cows treated 41 to 60 days postpartum than cows treated 29 to 40 days postpartum (97.2 ± 27.1 vs 74.4 ± 19.7, P=0.084). Our study suggests that cows with VDS=1 may require treatment to recover fertility. Diagnosis and treatment of clinical endometritis based on a VDS grading system may improve dairy herd reproductive performance.

Effect of circulating exosomes from transition cows on Madin-Darby bovine kidney cell function

The greatest risk of metabolic and infectious disease in dairy cows is during the transition from pregnancy to lactating (i.e., the transition period). The objective of this experiment was to determine the effects of extracellular vesicles (microvesicles involved in cell-to-cell signaling) isolated from transition cows on target cell function. We previously identified differences in the protein profiles of exosomes isolated from cows divergent in metabolic health status. Therefore, we hypothesized that these exosomes would affect target tissues differently. To investigate this, 2 groups of cows (n = 5/group) were selected based on the concentration of β-hydroxybutyrate and fatty acids in plasma and triacylglycerol concentration in liver at wk 1 and 2 postcalving. Cows with high concentrations of β-hydroxybutyrate, fatty acids, and triacylglycerol were considered at increased risk of clinical disease during the transition period (high-risk group; n = 5) and were compared with cows that had low concentrations of the selected health indicators (low-risk group; n = 5). At 2 time points during the transition period (postcalving at wk 1 and 4), blood was sampled and plasma exosomes were isolated from the high-risk and low-risk cows. The exosomes were applied at concentrations of 10 and 1 µg/mL to 5 × 10³ Madin-Darby bovine kidney cells grown to 50% confluence in 96-well plates. Results indicate a numerical increase in cell proliferation when exosomes from high-risk cows were applied compared with those from low-risk cows. Consistent with an effect on cell proliferation, quantitative reverse transcriptase PCR indicated a trend for upregulation of 3 proinflammatory genes (granulocyte colony-stimulating factor, ciliary neurotrophic factor, and CD27 ligand) with the application of high-risk exosomes, which are involved in cellular growth and survival. Proteomic analysis indicated 2 proteins in the low-risk group that were not identified in the high-risk group (endoplasmin and catalase), which may also be indicative of the metabolic state of origin. It is likely that the metabolic state of the transition cow affects cellular function through exosomal messaging; however, more in-depth research into cross-talk between exosomes and target cells is required to determine whether exosomes influence Madin-Darby bovine kidney cells in this manner.

The RESET Mindset Model applied on decreasing antibiotic usage in dairy cattle in the Netherlands

Background

Prudent use of antibiotics is important to prevent antibiotic resistance in humans and in animals. For this reason politicians demanded a decrease of total antibiotic use and of use of critically important antibiotics in animal husbandry in the Netherlands. In the dairy sector the use of antibiotics almost halved in the years 2009–2015, with a decrease of the use of critically important antibiotics to very low levels.

Theory of behaviour change

To realize a sustainable decrease in antibiotic usage, the mindset towards the subject was considered crucial. Based on several models from social psychology, the RESET Mindset Model was used. This model contains the most important cues to change human behaviour, being Rules and regulations, Education and information, Social pressure, Economics, and Tools. To change behaviour of groups in order to reach a tipping point, it is of utmost importance to not choose among the different cues, but to use them all.

Changing antibiotic usage in dairy cattle

In order to decrease antibiotic usage in dairy cattle in the Netherlands several actions, obliged as well as voluntary, were undertaken. An independent veterinary medicine authority was founded that became active for all animal sectors. In the dairy sector a national database on antibiotic usage called MediRund was developed, which made transparency and benchmarking on antibiotic usage at the national and the herd level possible. Several other activities are described, such as herd health and treatment plans, selective dry cow therapy, and the strong limitation on the use of critically important antibiotics. Antibiotic usage at the herd level, referred to as the ‘antibiotic number’, became an important and socially accepted herd level parameter.

RESET the dairy farmer’s mindset on antibiotic usage

The actions undertaken worked through different cues, all part of the RESET Mindset Model. As such, different types of dairy farmers sensitive to different types of cues were motivated to change their behaviour.

Conclusion

Antibiotic usage in dairy cattle in the Netherlands decreased significantly by intense cooperation between the most important stakeholders in the dairy chain, taking communication seriously and applying the RESET Mindset Model.

Application of a bacteriological on-farm test to reduce antimicrobial usage in dairy cows with purulent vaginal discharge

The objective of this study was to assess the effect of a selective antibiotic treatment strategy based on a quick bacteriological on-farm test (Petrifilm, 3M Corp., St. Paul, MN) compared with the conventional antibiotic treatment of all cows having clinical endometritis (CE) defined by the presence of purulent vaginal discharge on both clinical cure rate and reproductive performance. The study was simultaneously conducted with dairy cows reared under a highly supplemented rotational grazing system in Argentina and in a freestall system in Slovakia. Cows having an abnormal vaginal discharge (VD, indicative of clinical endometritis) on 21 to 35 d in milk (DIM) were randomly allocated to 1 of 2 study groups: selective treatment (ST) or conventional treatment (CT). All cows in the CT group (n = 174) received a single intrauterine administration of 500 mg of cephapirin. In the ST group (n = 178), treatment decision was made according to the results of the bacteriological on-farm test. For this test, we collected intrauterine samples with the cytobrush technique and stroke the brushes onto 2 different Petrifilm plates, one for aerobic count and another for Enterobacteriaceae count, incubated the plates, and counted the number of colonies after 24 h. Positive cows (≥5 colonies in one or both plates) received a single intrauterine treatment with 500 mg of cephapirin, whereas negative cows (<5 colonies) remained untreated. Clinical cure rate was assessed by direct vaginal inspection at 14 d after treatment (VD-0). The odds for conception at first artificial insemination, artificial insemination by 80 DIM, pregnancy by 100 DIM, and for nonpregnancy by 200 DIM were estimated with mixed logistic regression models. The hazard of conception was also assessed with proportional hazard regression model. The selective antibiotic treatment strategy based on the outcome of Petrifilm test reduced the number of required treatments (57%) and maintained similar efficacy in terms of clinical cure and reproductive performance as the conventional antibiotic treatment of all endometritic cows.

Effects of platelet-rich plasma in a model of bovine endometrial inflammation in vitro

BACKGROUND

Endometritis reduces fertility and is responsible for major economic losses in beef and dairy industries. The aim of this study was to evaluate an alternative therapy using platelet-rich plasma (PRP). PRP was tested in vivo, after bovine intrauterine administration, and in vitro on endometrial cells.

METHODS

Bovine endometrial cells were cultured until passage (P) 10 with 5 % or 10 % PRP. Effect of PRP on endometrial cell proliferation and on the expression of genes [prostaglandin-endoperoxide synthase 2 (COX2), tumor protein p53 (TP53), oestrogen receptors (ER-α and ER-β), progesterone receptor (PR) and c-Myc] involved in the regulation of oestrus cycle and fetal-maternal interaction were evaluated. Moreover, to evaluate the ability of PRP to counteract inflammation, 10 and 100 ng/ml of bacterial endotoxin lipopolysaccharide (LPS) were used to inflame endometrial cells in vitro for 1, 6, 12, 24 and 48 h. The expression of genes such as interleukin 1β (IL-1β), interleukin-8 (IL-8), inducible nitric oxide synthase (iNOS), prostaglandin-endoperoxide synthase 2 (COX2/PTGS2), and the release of PGE-2, IL-1β and IL-8 were evaluated.

RESULTS

In vivo treatment with PRP increased the detection of PR. In vitro, 5 % PRP at passage 5 increased proliferation rate and induced a significant increase in the expression of all studied genes. Furthermore, the results revealed that 10 ng/ml of LPS is the most effective dose to obtain an inflammatory response, and that PRP treatment significantly down regulated the expression of pro-inflammatory genes.

CONCLUSION

This study lays the foundations for the potential treatment of endometritis with PRP in vivo.

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.

Associations among Trueperella pyogenes, endometritis diagnosis, and pregnancy outcomes in dairy cows

The objective of this study was to evaluate three commonly used methods for endometritis diagnosis by comparing each one's association with the presence of intrauterine Trueperella pyogenes (TP) and reproductive performance. Lactating Holstein cows (n = 452) were evaluated a single time at 35 ± 3 days postpartum to diagnose endometritis on the basis of three criteria: presence of purulent vaginal discharge (PVD) detected by a Metricheck device, presence of purulent uterine lavage fluid (PUL), presence of cytologic endometritis (CE) based on relative abundance of polymorphonuclear leukocytes in uterine lavage fluid. A threshold of polymorphonuclear leukocytes greater than 5% was used to diagnose the occurrence of CE. Also, a swab of the uterine lavage was cultured to evaluate the presence of TP and determine its association with endometritis diagnosis criteria and pregnancy outcomes. The results showed that cows positive for TP had increased prevalence of PVD and PUL and tended to have greater prevalence of CE. Median time to pregnancy was 56 days longer, and hazard of pregnancy was 34% lower for TP-positive cows than for TP-negative cows. Presence of PUL led to a 35% lower hazard of pregnancy and 34-day-longer median time to pregnancy than cows without PUL. Likewise, cows diagnosed with PVD had a 47% lower hazard of pregnancy and 57-day-longer median time to pregnancy than cows without PVD. Cows diagnosed with CE had a 27% lower hazard of pregnancy and 42-day-longer median time to pregnancy than cows without CE. When the three different diagnostic methods were used as independent variables in a Cox's proportional hazard model that evaluated hazard of pregnancy, the variable PVD was the only statistically significant variable. Combined PUL and CE or combined PUL and PVD had no additional effects on hazard of pregnancy when compared with only PUL, only PVD, or only CE as the criterion to determine endometritis. However, combined PVD and CE had an additive detrimental effect on reproductive performance. The sensitivity and specificity of each of TP, PUL, PVD, and CE for predicting nonpregnancy at 300 days postpartum were all similar. In conclusion, TP-positive cows had impaired reproductive performance and increased likelihood of PVD and PUL. Additionally, TP-positive cows tended to have an increased prevalence of CE. Cows with PVD had the lowest reproductive performance when compared to cows with PUL or CE, suggesting that PVD at 35 days postpartum is a better criterion for the diagnosis of endometritis and reproductive failure.

Treatment of clinical endometritis in dairy cows by previously used controlled internal drug release devices

Postpartum endometritis is considered as one of the diseases that lead to a potential profit reduction in dairy cows. The aims of the present study were to promote follicle growth by a previously used controlled internal drug release (CIDR) device and to evaluate its effect on the likelihood of recovery and the reproductive performance of clinical endometritis (CE) cows. Endometritis was diagnosed using ultrasonographic examination at 31 ± 3 (Day 0 of the experiment) days in milk, and CE cows were included in one of the three experimental groups according to the presence of a CL on their ovaries. Cows without CL on their ovaries received a reused CIDR device, which was previously used for 14 days (CIDR-14, n = 108), or PGF2α (PG-1, n = 112) on Day 0. In the third group, those with CL on their ovaries received PGF2α (PG-2, n = 107) at the same time. Ovarian structures, serum estradiol and progesterone concentrations were measured on Days 0, 7, and 14. Controlled internal drug release devices were removed, and response to treatment was evaluated in all treated cows on Day 14. Diameters of ovarian follicles were 11.61 ± 0.50, 12.46 ± 0.25, and 18.36 ± 0.60 mm on Day 7 and 11.63 ± 0.58, 14.35 ± 0.40, and 21.96 ± 0.77 mm on Day 14 in PG-1, PG-2, and CIDR-14 cows, respectively (P < 0.05). Serum estradiol concentrations were higher in CIDR-14 cows (141.17 ± 1.04 pg/mL) than in PG-1 (116.85 ± 1.05 pg/mL) and PG-2 (119.10 ± 1.05 pg/mL) cows on Day 7 (P < 0.05). Higher progesterone concentrations were observed in PG-2 cows than in PG-1 and CIDR-14 cows on Days 0, 7, and 14 (P < 0.001). The likelihood of clinical cure was 54.46%, 62.61%, and 64.81% in PG-1, PG-2, and CIDR-14 cows, respectively (P = 0.11). First-service conception risk, days to the first service, calving to conception interval, proportion of cows bred and pregnant by 120 days in milk did not differ among the treated groups (P > 0.05). The cumulative pregnancy risk was lower in PG-1 (77.67%) cows than in CIDR-14 (87.07%) and PG-2 (87.85%) cows (P = 0.02). In conclusion, reused CIDR would be contributed to the treatment of CE by promotion of follicle growth and induction of sustainable sources of endogenic estrogen secreted by the dominant follicle.

Modulation of the immune system during postpartum uterine inflammation

Postpartum uterine inflammation (endometritis) in the dairy cow is associated with lower fertility at both the time of infection and after the inflammation has resolved. We hypothesized that aberrant DNA methylation may be involved in the subfertility associated with uterine inflammation. The objective of this study was to characterize genome-wide DNA methylation and gene expression in the endometrium of dairy cows with subclinical endometritis (SCE). Endometrial tissues were obtained at 29 days postpartum ( n = 12), and microarrays were used to characterize transcription and DNA methylation. Analyses revealed 1,856 probes differentially expressed in animals with SCE ( n = 6) compared with controls (CON, n = 6, P < 0.05, Storey Multiple testing correction) and 2,976 probes with significant correlation between gene expression and bacteriology score. No significant associations among DNA methylation and gene expression were detected. Analysis of transcription data using the Database for Annotation, Visualization, and Integrated Discovery and Gene Set Enrichment Analysis identified several pathways and processes enriched in SCE cows, with the majority related to the immune response. Furthermore, the top ontology terms enriched in genes that had expression data correlated to bacteriology score were: Defense response, inflammatory response, and innate immune response. Gene expression profiles in cows with subclinical endometritis in this study indicate that the immune response is activated, potentially resulting in a local proinflammatory environment in the uterus. If this period of inflammation is prolonged it could result in tissue damage or failure to complete involution of the uterus, which may create a suboptimal environment for future pregnancy.

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.