In vitro antimicrobial resistance of Escherichia coli, Serratia marcescens, Klebsiella oxytoca and Klebsiella pneumoniae on Bavarian dairy farms between 2014-2022.

The objective of this study was to describe the prevalence of antimicrobial resistance of E. coli, K. oxytoca, K. pneumoniae, and S. marcescens from quarter milk samples submitted to the udder health laboratory of the Bavarian Animal Health Services (TGD) in Southern Germany between 2014 and 2022. All samples were tested with the California Mastitis Test and analyzed with a standard microbroth dilution to determine the minimum inhibitory concentrations (MIC). The antimicrobials tested were amoxicillin/clavulanate, cefazoline, kanamycin/cefalexin, cefoperazone, cefquinome, and marbofloxacin. Breakpoints were chosen in accordance with CLSI. Over the study period, E. coli, K. oxytoca, and K. pneumoniae showed only few resistances to all antimicrobials tested. For those pathogens MIC 50 and MIC 90 were below breakpoint for all antimicrobials except cefoperazone over the 9 years. A decrease in MIC could be seen for E. coli and K. oxytoca for all of the antimicrobials. While the MIC for K. pneumoniae stayed more stagnant, the prevalence of resistance still decreased overall. S. marcescens isolates were proven intrinsically resistant to amoxicillin/clavulanate and cefazolin and while in vitro resistances were low for all other antimicrobials tested, S. marcescens tended toward higher MIC for most of the antimicrobials over the years. Over time, there was also an overall increase in the number of isolates for all 4 pathogens per year. Starting 2018 there was steep increase in the number of isolates particularly from clinical cases. This jump in numbers coincided with a change of the regulation for veterinary drug prescriptions in Germany in 2018 that required, among other things, antimicrobial resistance testing before a change of antibiotics in the course of treatment and the use of critically important antimicrobials. Overall, while the pathogens increased in numbers, the prevalence of their antimicrobial resistance remained low.

[Selective dry cow therapy on dairy farms in Southern Germany - a case series]. / Selektives Trockenstellen auf bayerischen Betrieben ­ eine Fallserie.

The aim of this case series was to describe how the selective dry-off therapy affected the udder health of Bavarian dairy farms under field conditions as well as to record whether a long-term reduction in antibiotic dry-off therapy was feasible. Between 2016 and 2021, 90 herds participated. A subset of dairy herds participated over a period of several years. Quarter milking samples were taken annually from all lactating cows in the herds, and treatment and test day results were evaluated. Major pathogens were detected during the initial whole herd testing (e. g., Streptococcus agalactiae, Streptococcus canis) and the treatment regimen needed to be adjusted. Even though the median treatment risk decreased, at least numerically, from 63% to 50%, the treatment rate in individual herds could vary greatly between years (-60% to+40%). Selective dry-off therapy can be implemented without endangering the udder health of the herd.

Sensitivity and Specificity for the Detection of Clinical Mastitis by Automatic Milking Systems in Bavarian Dairy Herds.

In automatic milking systems (AMSs), the detection of clinical mastitis (CM) and the subsequent separation of abnormal milk should be reliably performed by commercial AMSs. Therefore, the objectives of this cross-sectional study were (1) to determine the sensitivity (SN) and specificity (SP) of CM detection of AMS by the four most common manufacturers in Bavarian dairy farms, and (2) to identify routinely collected cow data (AMS and monthly test day data of the regional Dairy Herd Improvement Association (DHIA)) that could improve the SN and SP of clinical mastitis detection. Bavarian dairy farms with AMS from the manufacturers DeLaval, GEA Farm Technologies, Lely, and Lemmer-Fullwood were recruited with the aim of sampling at least 40 cows with clinical mastitis per AMS manufacturer in addition to clinically healthy ones. During a single farm visit, cow-level milking information was first electronically extracted from each AMS and then all lactating cows examined for their udder health status in the barn. Clinical mastitis was defined as at least the presence of visibly abnormal milk. In addition, available DHIA test results from the previous six months were collected. None of the manufacturers provided a definition for clinical mastitis (i.e., visually abnormal milk), therefore, the SN and SP of AMS warning lists for udder health were assessed for each manufacturer individually, based on the clinical evaluation results. Generalized linear mixed models (GLMMs) with herd as random effect were used to determine the potential influence of routinely recorded parameters on SN and SP. A total of 7411 cows on 114 farms were assessed; of these, 7096 cows could be matched to AMS data and were included in the analysis. The prevalence of clinical mastitis was 3.4% (239 cows). When considering the 95% confidence interval (95% CI), all but one manufacturer achieved the minimum SN limit of >80%: DeLaval (SN: 61.4% (95% CI: 49.0%−72.8%)), GEA (75.9% (62.4%−86.5%)), Lely (78.2% (67.4%−86.8%)), and Lemmer-Fullwood (67.6% (50.2%−82.0%)). However, none of the evaluated AMSs achieved the minimum SP limit of 99%: DeLaval (SP: 89.3% (95% CI: 87.7%−90.7%)), GEA (79.2% (77.1%−81.2%)), Lely (86.2% (84.6%−87.7%)), and Lemmer-Fullwood (92.2% (90.8%−93.5%)). All AMS manufacturers' robots showed an association of SP with cow classification based on somatic cell count (SCC) measurement from the last two DHIA test results: cows that were above the threshold of 100,000 cells/mL for subclinical mastitis on both test days had lower chances of being classified as healthy by the AMS compared to cows that were below the threshold. In conclusion, the detection of clinical mastitis cases was satisfactory across AMS manufacturers. However, the low SP will lead to unnecessarily discarded milk and increased workload to assess potentially false-positive mastitis cases. Based on the results of our study, farmers must evaluate all available data (test day data, AMS data, and daily assessment of their cows in the barn) to make decisions about individual cows and to ultimately ensure animal welfare, food quality, and the economic viability of their farm.

Effects of Pre-Parturient Iodine Teat Dip Applications on Modulating Aversive Behaviors and Mastitis in Primiparous Cows.

Heifers and their human handlers are at risk for decreased welfare during the early lactation period. This experiment investigated pre-parturient teat dipping and parlor acclimation to reduce mastitis and aversive behaviors in early lactation heifers. Three weeks prior to calving, heifers were randomly assigned to receive either: (1) a weekly 1.0% iodine-based teat dip in the parlor (trained; n = 37) or (2) no treatment (control; n = 30). For the first 3 days of lactation, heifers were milked twice daily, and treatment-blinded handlers assessed behaviors and clinical mastitis. Aseptic quarter milk samples were collected within 36 h of calving and analyzed for pathogens. Control heifers had (OR ± SE) 2.2 ± 0.6 times greater (p < 0.01) odds of kicking during milking. Trained heifers had (OR ± SE) 1.7 ± 0.4 times greater (p = 0.02) odds of being very calm during milking, while control heifers had 2.2 ± 0.8 and 3.8 ± 2.1 times greater (p < 0.04) odds of being restless and very restless or hostile during milking, respectively. Quarters of control heifers had (OR ± SE) 5.4 ± 3.4 greater (p < 0.01) odds of intramammary Staphylococcus aureus infection, yet clinical mastitis was similar among treatments. The results indicate that teat dipping in the parlor weekly for 3 weeks before calving may alleviate some aversive milking behaviors and protect against early lactation S. aureus intramammary infections.

In vitro antimicrobial resistance profiles of Streptococcus uberis, Lactococcus spp., and Enterococcus spp. from quarter milk samples of cows between 2015 and 2019 in Southern Germany.

The objective was to describe and compare antimicrobial resistance patters of esculin-hydrolyzing streptococci and streptococcal-like organisms (Streptococcus uberis, Enterococcus faecium, Enterococcus faecalis, Lactococcus garvieae, Lactococcus lactis) from routine diagnostic samples of the udder health laboratory of the Bavarian Animal Health Services between 2015 and 2019. All routine diagnostic samples of the udder health laboratory of the Bavarian Animal Health Services, that were tested with a standard microbroth dilution, were eligible to be included in this retrospective case series. A California Mastitis Test result was available for all samples. Most Strep. uberis and L. lactis were susceptible to all antibiotics tested. Enterococcus faecium had consistently the highest minimum inhibitory concentration required to inhibit the growth of 90% of tested isolates. The resistance patterns of Lactococcus garvieae were positioned between enterococci and L. lactis. The minimum inhibitory concentration for various antibiotics and pathogens tended to decrease over the 5-yr period. Regardless of the pathogen, isolates of clinical cases were less likely to express in vitro resistance than isolates of healthy or subclinical cases. Streptococcus uberis or L. lactis showed hardly any in vitro resistance to tested antibiotic groups. Penicillin should remain the first-choice antimicrobial for the therapy of Strep. uberis and Lactococcus spp. However, a success of any antimicrobial treatment of enterococcal infections seems questionable.

Efficacy of Broilers as a Method of Face Fly (Musca autumnalis De Geer) Larva Control for Organic Dairy Production.

The objective of this study was to evaluate Freedom-Ranger broiler chickens as a method to control face fly (Musca autumnalis De Geer) larvae in cow dung pats on pasture. Ninety-nine pats in three replicates were inoculated with first-instar larvae and exposed to one of four treatment conditions for 3 to 4 days: (1) an environment-controlled greenhouse (GH); (2) pasture without broilers (NEG); (3) pasture with 25 broilers stocked at a low density of 2.5 m2 of outdoor area per broiler (LOW); and (4) pasture with 25 broilers stocked at a high density of 0.5 m2 of outdoor area per broiler (HIGH). Broiler behaviors and weather conditions were recorded twice daily. Survival rates of larvae (mean, 95% CI) were similar for pats in the NEG (4.4%, 2-9%), LOW (5.6%, 3-11%), and HIGH (3.2%, 2-7%) groups, and was greatest for larvae reared in the GH (54.4%, 36-72%) group compared to all other groups. The proportion of broilers observed pasture ranging was 14.0% (6-28%) but was negatively related to solar radiation. Broilers were never observed foraging in pats. Results indicate that use of broilers may not be an effective method for controlling larvae of dung pat breeding flies.

Development and Implementation of a National Center of Excellence in Dairy Production Medicine Education for Veterinary Students: Description of the Effort and Lessons Learned.

The need for consortial programs to provide advanced education in food animal veterinary production medicine has been recognized and lauded for nearly three decades. This article describes one effort to create a dairy production medicine curriculum funded by a United States Department of Agriculture (USDA) Higher Education Challenge Grant. This National Center of Excellence in Dairy Production Medicine Education for Veterinarians is housed at the Dairy Education Center of the University of Minnesota and the project was a collaboration of the University of Minnesota, the University of Illinois, the University of Georgia, and Kansas State University. The article reviews the need for innovative ways to educate students who will optimally serve the dairy industry, provides a broad overview of the process of developing and delivering the eight-week dairy production medicine curriculum, and describes the challenges faced and lessons learned as a result of offering such a program.

Short communication: Metagenomic evaluation of skin biopsies of udder sores in dairy cows.

The objectives of this study were (a) to evaluate skin biopsies of udder sores and negative control cows for the presence of mange and nonbacterial pathogens via histopathology and (b) to identify and compare bacterial abundance in the lesions of cows with udder sores and from the skin of healthy controls from the same farms. Cows from 3 dairy farms with (n = 23) and without (n = 12) udder sore lesions were enrolled, and punch biopsies (23 lesions, 23 negative control samples of cows with lesions, and 12 control samples of cows without lesions) were collected. The biopsies were evaluated histopathologically, and their 16S metagenome was analyzed. No signs of mange or viral or fungal infections were detected histopathologically in any samples. The α diversity of microbial populations decreased in lesions, across all farms, and the abundance of spirochaetes did not notably change, compared with controls. However, compared with control samples, the microbial fractions of Fusobacterium, Helcococcus spp., Anaerococcus spp., Porphyromonas spp., Prevotella spp., and Trueperella spp. increased several-fold in lesions. In summary, our results suggest that spirochaetes, viruses, and mange are unlikely to cause udder sores. Instead, sores were associated with a marked increase in the abundance of Fusobacterium, Helcococcus, Anaerococcus, Porphyromonas, Prevotella, and Trueperella. Future studies are needed to determine which of these bacteria initiates this polymicrobial infection.

Bovine veterinarians' perspective on organic livestock production in the USA.

The objective was to determine possible challenge areas that bovine veterinarians may face when working on certified organic livestock operations. All members of the American Association of Bovine Practitioners' electronic mailing list, who practised in the USA, were invited to participate in an anonymous online survey. Veterinarians (n=213) from 38 states participated in the survey. The focus of the survey was on the veterinarian's interest in and perception of organic farming, their knowledge of the use of alternative therapies under federal regulations and their needs for providing veterinary services to organic farms. Most participants worked in dairy practice and served ≥1 organic client. Their attitude towards organic production was balanced. Many veterinarians struggled to offer sick animal care with alternative therapies within the regulatory framework and expressed their need to have more evidence-based alternative therapies. Two-thirds of veterinarians were concerned that the lack of proven effective therapy options would impair livestock welfare on organic farms in the USA. Almost 90 per cent of respondents did not think that organic livestock was healthier than conventionally raised livestock and most participants (74 per cent) thought livestock health was dependent on management rather than organic or conventional farming practices. In summary, participants were generally not opposed to organic farming. However, most veterinarians expressed their need to have a better access to clear information about organic regulations and most importantly more evidence-based alternative therapies to ensure animal health and welfare on organic livestock operations.

Clinical indications, complications, and long-term outcome of esophageal surgeries in 27 horses.

The main objective of this retrospective study was to describe clinical findings, management, and short- and long-term outcome in 27 horses that underwent various surgical techniques for esophageal disease. Surgical techniques (sometimes concurrently) performed were: esophagostomy (n = 14), esophagotomy with primary closure (n = 6), esophagomyotomy (n = 3), and esophagoplasty (n = 2). Esophageal perforation in 5 horses was treated by ventral drainage; 3 horses had the esophageal defect sutured (n = 3). Feeding tubes were placed in 15 horses. Postoperative complications occurred in 52% (14/27) with a median of 3 complications/horse (range: 1 to 7). Significantly more complications occurred in horses with a perforated esophagus. Eighteen horses (18/27; 67%) were discharged. Most horses (8/9; 89%) with a lesion located in the proximal esophagus were discharged. Horses with a higher number of postoperative complications, particularly postoperative infection, were more likely to be euthanized. One year after surgery, 41% of the horses were alive and free of complications.

Indications cliniques, complications et résultat à long terme de chirurgies œsophagiennes chez 27 chevaux. L'objectif principal de cette étude rétrospective a été de décrire les résultats cliniques, la gestion et les résultats à court et à long terme chez 27 chevaux qui ont subi diverses techniques de chirurgie pour le traitement de la maladie œsophagienne. Les techniques chirurgicales réalisées (parfois de manière concomitante) étaient : l'œsophagostomie (n = 14), l'œsophagotomie avec fermeture primaire (n = 6), l'œsophagomyotomie (n = 3) et l'œsophagoplastie (n = 2). La perforation œsophagienne chez 5 chevaux a été traitée par drainage ventral; 3 chevaux ont subi une suture du défaut œsophagien (n = 3). Des sondes d'alimentation ont été placées chez 15 chevaux. Les complications postopératoires se sont produites chez 52 % des chevaux (14/27) avec une médiane de 3 complications/cheval (fourchette : 1 à 7). Un nombre significativement supérieur de complications se sont produits chez les chevaux ayant une perforation de l'œsophage. Dix-huit chevaux (18/27; 67 %) ont reçu leur congé. La plupart des chevaux (8/9; 89 %) ayant une lésion situé dans l'œsophage proximal ont reçu leur congé. Il était plus probable que les chevaux avec un nombre supérieur de complications postopératoires, particulièrement une infection postopératoire, soient euthanasiés. Un an après la chirurgie, 41 % des chevaux étaient vivants et libres de complications.(Traduit par Isabelle Vallières).

Comparing ELISA test-positive prevalence, risk factors and management recommendations for Johne's disease prevention between organic and conventional dairy farms in Ontario, Canada.

Johne's disease (JD) is a chronic, infectious disease in cattle. Between 2010 and 2013, a voluntary JD control program was successfully launched in Ontario, Canada, including a Risk Assessment and Management Plan (RAMP) and JD ELISA testing of the entire milking herd. Over the last decade, the organic dairy sector has been growing. However, organic farming regulations and philosophies may influence the risk for JD transmission on Ontario organic dairy farms. The aim of this cross-sectional study was to investigate differences in JD ELISA test positive prevalence, risk factors for JD and recommendations for JD prevention between organic and conventional dairy herds in Ontario. RAMP results (i.e. RAMP scores and recommendations) and ELISA results were available for 2103 dairy herds, including 42 organic herds. If available, additional data on milk production, milk quality, and herd characteristics were gathered. Organic and conventional herds had a similar herd-level JD ELISA test-positive prevalence (26.2% and 27.2%, respectively). Organic herds (4.2%) had a higher within-herd JD ELISA test-positive prevalence compared to conventional herds (2.3%) if they had at least one JD test-positive animal on the farm. Organic farms had lower risk scores for biosecurity (9 points lower), and higher scores in the calving (7 points higher) and the calf-rearing management areas (4 points higher). After accounting for RAMP score, organic farms received fewer recommendations for the calving management area (Odds Ratio=0.41) and more recommendations in the adult cow management area (Odds Ratio=2.70). A zero-inflated negative binomial model was built with purchase of animals and the herd size included in the logistic portion of the model. Herd type (organic or conventional), colostrum and milk feeding practices, average bulk tank somatic cell count, and presence of non-Holstein breeds were included in the negative binomial portion of the model. Organic farms had a higher number of test positive animals (Count Ratio=2.02). Further research is necessary to investigate the apparent disconnect between risk factors and recommendations on organic dairy farms.

Evaluation of the Johne's disease risk assessment and management plan on dairy farms in Ontario, Canada.

Johne's disease (JD) is a production-limiting gastrointestinal disease in cattle. To minimize the effects of JD, the Ontario dairy industry launched the Ontario Johne's Education and Management Assistance Program in 2010. As part of the program, trained veterinarians conducted a risk assessment and management plan (RAMP), an on-farm questionnaire where high RAMP scores are associated with high risk of JD transmission. Subsequently, veterinarians recommended farm-specific management practices for JD prevention. Milk or serum ELISA results from the milking herd were used to determine the herd ELISA status (HES) and within-herd prevalence. After 3.5 yr of implementation of the program, the aim of this study was to evaluate the associations among RAMP scores, HES, and recommendations. Data from 2,103 herds were available for the analyses. A zero-inflated negative binomial model for the prediction of the number of ELISA-positive animals per farm was built. The model included individual RAMP questions about purchasing animals in the logistic portion, indicating risks for between-herd transmission, and purchasing bulls, birth of calves outside the designated calving area, colostrum and milk feeding management, and adult cow environmental hygiene in the negative binomial portion, indicating risk factors for within-herd transmission. However, farms which fed low-risk milk compared with milk replacer had fewer seropositive animals. The model additionally included the JD herd history in the negative binomial and the logistic portion, indicating that herds with a JD herd history were more likely to have at least 1 positive animal and to have a higher number of positive animals. Generally, a positive association was noted between RAMP scores and the odds of receiving a recommendation for the respective risk area; however, the relationship was not always linear. For general JD risk and calving area risk, seropositive herds had higher odds of receiving recommendations compared with seronegative herds if the section scores were low. This study suggests that the RAMP is a valuable tool to assess the risk for JD transmission within and between herds and to determine farm-specific recommendations for JD prevention.

Comparison of laparoscopic versus conventional open cryptorchidectomies on intraoperative and postoperative complications and duration of surgery, anesthesia, and hospital stay in horses.

Objective-To compare surgical preparation time, surgery and anesthesia times, hospitalization duration, and intra- and postoperative complications between laparoscopic and conventional open cryptorchidectomy in horses. Design-Retrospective cohort study. Animals-60 horses that underwent cryptorchidectomy. Procedures-Medical records were reviewed to identify horses that had undergone cryptorchidectomy from 1991 to 2012. Thirty horses that underwent laparoscopic cryptorchidectomy (case horses) were matched with 30 control horses that had undergone open cryptorchidectomy (ie, inguinal and parainguinal surgical approaches). Horses were matched according to history of previous surgery, testicle location, and type of closure following removal of an undescended unilateral testicle. Duration of surgery, surgical preparation and anesthesia times, hospitalization duration, and number of intra- and postoperative complications were compared between horses that underwent laparoscopic cryptorchidectomy versus open cryptorchidectomy. Comparisons were also made between horses in terms of whether there was a history of previous failed cryptorchidectomy or unknown location of testicle prior to surgery. Results-Horses that underwent laparoscopic cryptorchidectomy had significantly longer surgery and anesthesia times overall, compared with horses that underwent open cryptorchidectomy. No difference in surgery time was found between case and control horses that had a previous surgical attempt to remove an undescended testicle or in which the testicle location was unknown prior to surgery. Overall, horses undergoing laparoscopy had a nonsignificant increase in intraoperative complications, compared with control horses, and had significantly more postoperative complications. Conclusions and Clinical Relevance-Horses undergoing laparoscopic cryptorchidectomy had increased surgical preparation time, increased surgery and anesthesia times, and more postoperative complications, compared with horses undergoing open cryptorchictomy. Laparoscopy may be advantageous for a second attempt at cryptorchidectomy or if the testicle location is unknown prior to surgery.

Variability in Risk Assessment and Management Plan (RAMP) scores completed as part of the Ontario Johne's Education and Management Assistance Program(2010-2013).

As a proactive measure toward controlling the nontreatable and contagious Johne's disease in cattle, the Ontario dairy industry launched the voluntary Ontario Johne's Education and Management Assistance Program in 2010. The objective of this study was to describe the results of the first 4 yr of the program and to investigate the variability in Risk Assessment and Management Plan (RAMP) scores associated with the county, veterinary clinic, and veterinarian. Of 4,158 Ontario dairy farms, 2,153 (51.8%) participated in the program between January 2010 and August 2013. For this study, RAMP scores and whole-herd milk or serum ELISA results were available from 2,103 farms. Herd-level ELISA-positive prevalence (herds with one or more test-positive cows were considered positive) was 27.2%. Linear mixed model analysis revealed that the greatest RAMP score variability was at the veterinarian level (24.2%), with relatively little variability at the county and veterinary clinic levels. Consequently, the annual RAMP should be done by the same veterinarian to avoid misleading or discouraging results.

Detection of Mycobacterium avium subspecies paratuberculosis in the saliva of dairy cows: a pilot study.

Johne's disease (JD) is a production limiting, intestinal disease of ruminants that is caused by Mycobacterium avium subsp. paratuberculosis (MAP). Transmission of MAP occurs predominately through feces, colostrum and milk. Since other intestinal bacteria can be found in saliva, it possible that saliva might serve as a previously overlooked route of MAP transmission. Therefore, the objective of this study was to investigate whether MAP is present in the saliva of cows. Methods were validated using MAP K10 spiked saliva samples of cows from a voluntary JD control program level 4 herd and applied to saliva and fecal samples of cows from a known infected herd. The matched pairs of saliva and feces were analyzed for MAP with PCR and culture. Fourteen of the twenty-six sampled cows were saliva positive by conventional PCR. The fecal samples of 10 and 6 cows were positive by realtime PCR and MAP culture, respectively. Overall there was a poor agreement between saliva and fecal PCR results for MAP (kappa 0.24). This is the first study that detected MAP in the saliva of cows. The finding needs further investigation to identify the source of MAP in saliva and to quantify the role of this newly identified route of MAP emission for the transmission of MAP infections on farm.

Risk factors for herds to test positive for Mycobacterium avium ssp. paratuberculosis-antibodies with a commercial milk enzyme-linked immunosorbent assay (ELISA) in Ontario and western Canada.

The objectives of this study were to identify risk factors associated with i) a Mycobacterium avium subsp. paratuberculosis (MAP)-antibody milk enzyme-linked immunosorbent assay (MAP milk ELISA)-positive herd status, and ii) the within-herd MAP milk ELISA-positive prevalence in Canadian dairy herds. This prospective cohort study was conducted between 2005 and 2009 on 226 herds in Ontario and western Canada, which participated in a voluntary risk assessment (RA)-based Johne's disease control program. Two MAP milk ELISA and risk assessments and a previsit survey were available per herd. The overall farm RA scores alone could not be used to predict whether a herd would test positive for MAP antibodies. However, the results of this study indicated that increasing the likelihood of exposing calves to MAP through certain management practices, as assessed with the RA, increased the likelihood of a herd being test-positive for MAP antibodies.The objectives of this study were to identify risk factors associated with i) a Mycobacterium avium subsp. paratuberculosis (MAP)-antibody milk enzyme-linked immunosorbent assay (MAP milk ELISA)-positive herd status, and ii) the within-herd MAP milk ELISA-positive prevalence in Canadian dairy herds. This prospective cohort study was conducted between 2005 and 2009 on 226 herds in Ontario and western Canada, which participated in a voluntary risk assessment (RA)-based Johne's disease control program. Two MAP milk ELISA and risk assessments and a previsit survey were available per herd. The overall farm RA scores alone could not be used to predict whether a herd would test positive for MAP antibodies. However, the results of this study indicated that increasing the likelihood of exposing calves to MAP through certain management practices, as assessed with the RA, increased the likelihood of a herd being test-positive for MAP antibodies.

RésuméFacteurs de risque pour les troupeaux avec des résultats positifs lors d'un test ELISA pour détecter des anticorps enversMycobacterium aviumssp.paratuberculosisdans le lait commercial de l'Ontario et de l'Ouest canadien. Les objectifs de cette étude consistaient à identifier les facteurs de risque associés à i) un statut positif du troupeau détecté lors d'un test ELISA pour les anticorps envers Mycobacterium avium ssp. paratuberculosis (MAP) dans le lait et ii) et la prévalence de tests ELISA positifs pour MAP au sein du troupeau dans les troupeaux laitiers canadiens. Cette étude prospective d'une cohorte a été réalisée entre 2005 et 2009 auprès de 226 troupeaux de l'Ontario et de l'Ouest canadien qui ont participé à un programme de contrôle de la paratuberculose basé sur une évaluation volontaire des risques. Deux tests ELISA pour MAP et évaluations des risques et une enquête préalable à la visite étaient disponibles pour chaque troupeau. Les notes globales de l'évaluation des risques de la ferme n'ont pas pu être utilisées pour prédire si un troupeau obtiendraient des tests positifs pour les anticorps de MAP. Cependant, les résultats de cette étude ont indiqué que l'augmentation de la probabilité d'exposition des veaux à MAP par le biais de certaines pratiques de gestion, telles qu'examinées lors de l'évaluation des risques, amplifiait la probabilité qu'un troupeau obtienne des résultats positifs pour les anticorps envers MAP.(Traduit par Isabelle Vallières).

Veterinarians' perspective on a voluntary Johne's disease prevention program in Ontario and western Canada.

A survey was conducted to assess the beliefs of veterinarians on Johne's disease (JD) and their attitudes towards the Canadian, risk assessment based, JD prevention program. The veterinarians surveyed believed Mycobacterium avium subsp. paratuberculosis may have zoonotic potential, liked the risk assessment based program, and thought it could lead to the prevention of other on-farm diseases.