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Aims: Mycobacterium avium subsp. paratuberculosis (MAP) is the etiological agent of Johne's disease. To survive within host macrophages, the pathogen secretes a battery of proteins to interfere with the immunological response of the host. One of these proteins is tyrosine phosphate A (PtpA), which has been identified as a secreted protein critical for survival of its close relative M. tuberculosis within infected macrophages., Methods and Results: In this study, the immune response to recombinant PtpA used as an antigen was investigated in a cohort of ∼1000 cows infected with MAP compared to negative control animals using ELISA. The sera from MAP-infected cows had significantly higher levels of antibodies against PtpA when compared to uninfected cows., Conclusions: The data presented here indicate that the antibodies produced against PtpA are sensitive enough to detect infected animals before the appearance of the disease symptoms., Significance and Impact of Study: The use of PtpA as an antigen can be developed as an early diagnostic test. Moreover, PtpA is a candidate antigen for detection of humoral immune responses in cows infected with MAP., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The study was conducted to assess the technical feasibility of studying the spatial and temporal interaction of traditionally herded livestock and wildlife using global positioning system (GPS) tracking technology in Northern Kenya. Two types of collars were used on nine cows: radio frequency and global system for mobile communications (GSM) collars and GPS-satellite (SAT) collars. Full results of cattle tracking were available for eight cows (3 GSM and 5 SAT) tracked between July 2008 and September 2010. A cumulative total of 1556 tracking days was recorded over the 17 month period. On average cows walked 10,203 m/day (average total monthly distance walked was 234 km). Significant seasonal differences were found; on average cows walked 9.607 m and 10,392 m per day in the rainy and the dry seasons, respectively. This difference was also significant for total monthly and daily distance walked between the dry and the rainy season. On average cows walked daily 9607 m and 10,392 m on the rainy and the dry season respectively. During the dry months a 48 h cycle was observed with cows walking 15-25 km to water every 2nd day but only 5-8 km/day between watering days. There was a 24% overlap of cattle range with both elephants and zebras. This study demonstrated the feasibility of tracking cattle using radio collars. It shows the complexity of spatial use by cattle and wildlife. Such information can be used to understand the dynamics of disease transmission between livestock and wildlife., (Copyright © 2013 Elsevier B.V. All rights reserved.)

We assessed the potential of white-tailed deer (WTD) (Odocoileus virginianus) to be a sentinel for human cases of Lyme disease (LD) in Indiana using location data from a 3-year survey of approximately 3400 hunted deer with associated tick Ixodes scapularis and Borrelia burgdorferi (Bb) data. Data on human LD cases at the county level were obtained from the Indiana Department of Health. All data were assigned to county centroids to match the resolution of the LD data before creating optimized trend surfaces for LD incidence, hunted deer count, Ixodes scapularis and Bb prevalence. To determine whether LD was spatially associated with the areas of high densities of deer, deer with Ixodes scapularis and deer with ticks infected with Bb, we used spatial analysis with distance indices (SADIE). The SADIE analysis found significant spatial association between LD and the distribution of three organismal predictor variables, that is, WTD, Ixodes ticks and Bb. Lyme disease incident rate varied between 0.08 cases per 10,000 habitants (Johnson county) and 5.9 cases per 10,000 habitants (Warren county). In conclusion, WTD can be used as an accurate and cost-effective sentinel for human LD. This method will permit public health workers to identify potentially endemic areas independently of human case reports., (© 2012 Blackwell Verlag GmbH.)

Objective: To assess the transmission of bovine viral diarrhea virus (BVDV) from experimentally infected white-tailed deer fawns to colostrum-deprived calves by use of a BVDV strain isolated from hunter-harvested white-tailed deer., Animals: 5 white-tailed deer (Odocoileus virginianus) fawns and 6 colostrum-deprived calves., Procedures: Fawns were inoculated intranasally with a noncytopathic BVDV-1a isolate (2 mL containing 10(6.7) TCID(50)/mL), and 2 days after inoculation, animals were commingled until the end of the study. Blood and serum samples were obtained on days -6, 0, 7, 14, and 21 after inoculation for reverse transcriptase PCR assay, virus neutralization, and BVDV-specific antibody ELISA. Nasal, oral, and rectal swab specimens were collected on days 0, 3, 7, 14, 17, and 21 for reverse transcriptase PCR testing. By 21 days after inoculation, all animals were euthanized and necropsied and tissues were collected for histologic evaluation, immunohistochemical analysis, and virus isolation., Results: All fawns became infected and shed the virus for up to 18 days as determined on the basis of reverse transcriptase PCR testing and virus isolation results. Evidence of BVDV infection as a result of cohabitation with acutely infected fawns was detected in 4 of the 6 calves by means of reverse transcriptase PCR testing and virus isolation., Conclusions and Clinical Relevance: On the basis of these findings, BVDV transmission from acutely infected fawns to colostrum-deprived calves appeared possible.

The objective of this cross-sectional study was to describe the application of management practices known to be associated with the prevention of bovine viral diarrhea virus (BVDV) infection on Indiana dairy farms and to determine the extent of BVDV vaccine use within Indiana dairy herds. The population in this study was Indiana dairy producers enrolled under the Indiana Premise ID list by the Indiana State Board of Animal Health (n=1600). During the fall of 2008 a questionnaire was mailed to Indiana dairy producers. Returned questionnaires were entered into a database and descriptive statistics were performed. A total of 208 questionnaires were found useful for analysis. Small herds (<100 head) constituted 60% of the sample population, 33% farms were categorized as medium herds (100-499 head) and finally 7% were large herds (>500 head). Most of the herds (68%) acquired their replacements from external sources (open herds); however, preventive measures against the introduction of BVDV into the farm such as purchased animal history, quarantine and BVDV testing were not commonly performed. Even though producers commonly reported the use of BVDV vaccines, not all animals groups were vaccinated within herds. This study highlights the aspects of management practices of BVDV control on Indiana dairy farms that need reinforcement. In particular, dairy producers should be made aware that vaccination should be complementary to a comprehensive biosecurity program., (Copyright © 2011 Elsevier B.V. All rights reserved.)

The objective of this study was to describe the estimated within-herd prevalence (WHP) of Mycobacterium avium subsp. paratuberculosis (Map) in a sample of infected dairy herds in Minnesota (N = 66) using test results from bacterial culture of pooled fecal samples. Fecal samples were collected from up to 100 cows in each herd and were tested using bacterial culture in pools of 5 cows based on age order. The mean herd size was 222 (44 to 1500) milking cows; the cows were predominantly Holstein. Using a frequentist approach, the within-herd mean individual fecal prevalence was 10% [95% confidence interval (CI) = 4% to 16%] assuming 70% test sensitivity and 99.5% test specificity. Using Bayesian methods, the estimated true within-herd individual cow prevalence was 14% (95% CI = 7% to 27%). Within-herd prevalence was higher in larger dairy herds than in herds with fewer cows. As Map is the causative agent of Johne's disease (JD), the results of this study could contribute to the success of a nationwide control program for this disease.

The objectives of this cross-sectional study were to estimate the seroprevalence of infectious bovine rhinotracheitis (IBR, BHV-1) and bovine viral diarrhea virus (BVDV) in a population of non-vaccinated, double purpose, dairy and beef herds in the Pacific Region of Central Costa Rica. Blood samples were collected from a total of 496 animals from 35 herds. Sera were tested for antibodies against BHV-1(IBR) and BVDV types 1 and 2 using serum neutralization test. The average number of animals tested in each herd for each of the viruses was 14. Overall individual seroprevalence was 48%, 27%, and 19% for IBR, BVDV type 1, and BVDV type 2, respectively. Median within-herd seroprevalence for IBR, BVDV type 1 and type 2 were 43%, 27%, and 24%, respectively.

The objective of this study was to experimentally infect calves with bovine viral diarrhea virus (BVDV) isolated from free-ranging white-tailed deer. Twelve colostrum-deprived male Holstein calves were used. Eight were inoculated intranasally with a BVDV type 1a isolated from free-ranging white-tailed deer, and the other four were inoculated with the cell culture medium only and served as a control group. Whole blood, saliva, and nasal and rectal secretions were collected on days 0, 3, 7, 10, 14, 17, and 21 after inoculation for virus isolation and real-time reverse-transcriptase polymerase chain reaction (RT-PCR). On days 14 and 21, 4 calves in the infected group and 2 in the control group were euthanized; multiple tissue samples were collected for histopathologic study. Histopathologic changes included thymic atrophy and lymphoid depletion of the Peyer's patches in all 8 infected calves. The RT-PCR gave positive results with the buffy coat of all 8 infected calves, the nasal samples of 7, and the saliva samples of 2. Virus neutralization testing of the serum gave positive results for 4 of the 8 infected calves, and enzyme-linked immunosorbent assay of the serum gave positive results for 3. All of the samples from the control calves yielded negative results.

Mycobacterium avium subsp paratuberculosis (Map), the causative agent of Johne's disease, has a robust ability to survive in the environment. However, the ability of Map to migrate through soil to drainage tiles or ground water, leave the farm, and leak into local watersheds is inadequately documented. In order to assess the ability of Map to leach through soil, two laboratory experiments were conducted. In the first study, 8 columns (30 cm long each) of a sandy loam soil were treated with pure cultures of Map. Two soil moisture levels and two Map concentrations were used. The columns were leached with 500 mL of water once a week for three weeks, the leachate was collected, and detection analysis was conducted. In the second experiment, manure from Map negative cows (control) and Map high shedder cows (treatment) were deposited on 8 similar columns and the columns were leached with 500 mL of water once a week for four weeks. Map detection and numeration in leachate samples were done with RT-PCR and culture techniques, respectively. Using RT-PCR, Map could be detected in the leachates in both experiments for several weeks but could only be recovered using culture techniques in experiment one. Combined, these experiments indicate the potential for Map to move through soil as a result of rainfall or irrigation following application.

The objective was to evaluate the survival of Mycobacterium paratuberculosis (Map) in naturally infected dairy cows feces under long periods of freezing at -18°C and -70°C. Samples were collected from cows previously tested positive with serum ELISA or fecal culture, or with clinical signs of Johne's disease. Samples were stored at -18°C and/or -70°C and recultured in Herrold's egg yolk media every 3-6 months. A proportional odds mixed model was used for data analysis. Sixty nine fecal samples were stored for different periods between September 2002 and January 2005. Of these, 45 (65%) were stored at -18°C and 24 (35%) at -70°C. Average number of days between repeated culture dates was 98 and 84 for -18°C and -70°C, respectively. Median number of repeated cultures was 6 and 4 for samples stored at -18°C and -70°C, respectively. After adjusting for initial sample bacterial load, the effects of temperature or number of thawing and refreezing cycles on Map viability were not significant. The probability that a sample decreases from high to moderate-low bacterial load and from moderate-low to negative bacterial load was 13.5% per month. Although this study found gradual reduction of Map concentration in stored fecal samples through time, overall survival in -18°C can ease fecal samples management in laboratories with low-processing capacity or lack of -70°C freezer.

Species and biotype distribution was determined in 44 bovine viral diarrhea virus- (BVDV-) positive samples submitted to the Animal Disease Diagnostic Laboratory (ADDL) in Indiana during 2006-2008. BVDV RNA was detected in the 5'-untranslated region and N(pro) region using reverse transcriptase PCR followed by sequencing analysis of the PCR product. Additionally, cases were classified into one of six categories according to history and/or lesions: acute symptomatic, hemorrhagic, respiratory distress, reproductive, persistent infection (PI), and mucosal disease (MD). Of 44 BVDV-positive samples, 33 were noncytopathic (ncp), 10 were cytopathic (cp), and one presented both ncp and cp biotypes. Sequencing analysis demonstrated that all samples belonged to BVDV-1a, BVDV-1b, or BVDV-2. The most common isolate was ncp BVDV-1b, (44%) followed by ncp BVDV-2a (24%). Among the six categories, respiratory clinical signs were the most common (36%) followed by PI (25%) and MD (16%).

Unlabelled: The association between Mycobacterium avium subsp. paratuberculosis (MAP) and Crohn's disease (CD) is supported by several studies reporting the detection or isolation of MAP from human tissues, but a direct association is still debatable., Objective: To evaluate the survival of MAP in human intestinal cells and to measure the presence of antibodies against two mycobacterial proteins necessary for the survival of the bacterium in the sera of CD patients., Material and Methods: Human-derived intestinal cells were infected with three isolates of MAP and the survival of the microorganism was determined. The presence of antibodies against protein tyrosine phosphatase A (PtpA) and protein kinase G (two proteins secreted within the host in the early stages of the invasion) in the sera of CD patients was evaluated. Sera of 20 CD patients and 20 controls were collected and the presence of the antibodies was assayed using enzyme-linked immunosorbent assay (ELISA). Secretion of the PtpA in vivo was visualized by immunostaining., Results: MAP survived in intestinal cells, and immunostaining of PtpA showed that the protein was secreted within these cells. Wilcoxon rank sum test revealed that CD patient sera had significantly higher titer of antibodies specific for both of these antigens compared to controls. ELISA results for either protein were not statistically different between men and women., Conclusions: The presence of specific antibodies against mycobacterial proteins essential for establishing an infection in the host suggests that MAP can potentially be active in CD patients, and a serological test can be developed for early detection of MAP in CD patients.

The objective of this study was to assess whether the distribution of Borrelia burgdorferi, the causative agent of Lyme disease, and its vector tick Ixodes scapularis Say (Acari: Ixodidae) across Indiana is influenced by large-scale landscape features, specifically the proportion of forest within the surrounding landscape and the distance to water features such as lakes and major streams. Hunter-killed deer were checked for ticks in designated check-stations in the opening firearm hunting season between 2005 and 2007. Hunting locations for approximately 3,600 deer were used in ArcGIS (ESRI, Redlands, CA) to examine the influence of forest and water features in the surrounding area on the occurrence of the tick and bacteria. In total, 82 of the 92 (89%) Indiana counties were sampled from 2005 to 2007. The proportion of tick-infested deer was 13.6, 15.8, and 25.5% in these years, respectively. There was a significant nonlinear response for I. scapularis to forest cover in 1 yr that indicated a greater probability of this tick presence at intermediate levels of forest area. Infested does were harvested in significantly more forested areas than bucks. No significant correlation was found neither between levels of forest area and B. burgdorferi nor between water bodies and both organisms.

Ixodes scapularis (Say) is the vector for Borrelia burgdorferi (Bb) the causative agent of Lyme disease (LD). The increased number and presence of ticks in the environment pose a significant health risk to people and many domestic animals including dogs, cats, and horses. This study characterized the distribution and expansion of I. scapularis and Bb and identified areas of increased risk of LD transmission in Indiana using geographical information systems (GIS) and spatial analysis. A cross-sectional sampling was performed for 3 consecutive years (2005-2007). A total of 3,412 harvested white-tailed deer (Odocoileus virginianus) were searched for ticks at Department of Natural Resources manned deer check-in stations. Hunters were asked for verbal permission to search the deer and to indicate on a road atlas where the deer was killed. All deer points were digitized into a GIS database. Identification of clustering in space and time for these organisms was performed using geostatistical software. Multiple spatial clusters of I. scapularis-infested deer were identified in western Indiana. B. burgdorferi was isolated from tick pools in 11 counties. In addition to the I. scapularis clusters, one spatial cluster of Bb-infected ticks was identified. Our current survey results and cluster analysis indicate that the western geographic regions of Indiana should be considered by the healthcare community to be at increased risk of LD compared with the rest of Indiana.

Quantification of the financial effect of Mycobacterium paratuberculosis infection on lactation performance is essential to encourage participation of dairy cattle producers in Johne's disease (JD) control programs. The objective of this study was to evaluate the differences in net income per lactation of cows shedding Mycobacterium paratuberculosis before calving compared with test-negative cows. Two Minnesota dairies were enrolled in the study and fecal samples were collected from 1,048 cows during the close-up period. Milk production, clinical diseases (other than clinical JD), and reproductive performance data were recorded for each cow. Overall, fecal-culture-positive (FCP) cows produced 1,355 kg less than fecal-culture-negative (FCN) cows. Fecal-culture-positive cows that survived their current lactation produced $276 less in milk income than cows that were FCN ($1,956 vs. $1,680; SD $526, $570). Fecal-culture-positive cows were 3.0 (95% confidence interval: 1.6-5.8) times more likely to be culled than FCN cows. The mean days open (number of days from calving to conception) was not statistically significant and the cost differences for clinical disease other than JD were small and neither statistically nor economically significant between FCP and FCN cows. Among all FCP cows, income over feed costs losses were $366 per cow per lactation compared with FCN cows. Among FCP nonculled cows, income over feed costs losses were $276 more compared with FCN cows and this difference was statistically significant. There was a total loss of $155 per lactation for nonculled FCP cows retained in the herd compared with FCN cows retained in the herd. Among culled cows, FCP cow losses were $50 less because of age at culling and $120 for reduced beef value. This totaled a loss of $441 for culled FCP cows compared with culled FCN cows. The losses as a result of lower lactation performance and early culling from the herd should alarm dairy producers and motivate them to implement the appropriate control measures for the disease.

The objective of the current study was to elucidate the within-host dynamics of bovine viral diarrhea virus (BVDV) type-1 infection to better understand how this virus could be maintained in white-tailed deer (Odocoileus virginianus, WTD) populations. The BVDV type-1 used in this study was originally isolated from a free-ranging WTD in Indiana. Four fawns were intranasally inoculated with 2 ml BVDV type-1 strain 544 WTD at a 10(6) tissue culture infectious dose (TCID(50))/ml. Two fawns were inoculated with sham inoculum (negative controls). Animals were bled on days -7, 0, 1, 7, and 14 postinoculation (PID) for a complete blood count, chemistry panel, buffy coat (BC), real-time RT-PCR, and virus neutralization (VN). On days 7 and 14 PID, nasal and rectal swabs were obtained for RT-PCR and two of the virus-inoculated fawns and one of the negative controls fawns were euthanized. At necropsy, multiple samples were obtained for histopathology and in situ hybridization (ISH). Quantitative RT-PCR was performed on serum, BC, nasal, and rectal swabs. All animals tested negative for BVDV type 1 neutralizing antibodies on day 0 and animals in the control group remained seronegative throughout the study. No gross lesions were observed at necropsy. BVDV was isolated from lung and pooled lymph nodes from all BVDV-inoculated fawns on days 7 and 14 PID. Infected deer had lymphoid depletion, apoptosis, and lymphoid necrosis in the Peyer's patches and mesenteric lymph nodes. BVDV was detected in lymphoid tissues of infected animals by ISH. No lesions or virus were identified in control fawns. On day 7 PID, samples from two virus-inoculated fawns were positive for BVDV by virus isolation and RT-PCR from BC and nasal swab samples. One fawn was also positive on a rectal swab. Nasal and rectal swabs from all animals were negative on day 14. Results indicate that infection of WTD with BVDV is possible, and leads to histologic lesions in variety of tissues. In addition, virus shedding into the environment through feces and other secretions is likely.

The objective of this study was to evaluate the efficacy of single cow calving pens that are cleaned between calvings vs. multiple cow calving pens for the prevention of calf diarrhea (scours), respiratory disease (pneumonia) and morbidity attributable to any cause. Every other pregnant cow or heifer was moved to either the single cow calving pen (treatment) or the multiple cow calving pen (control) within 48-72 h prior to actual calving. The calves born in the single cow calving pens were assigned to the treatment group while the calves born in the multiple calving pens were assigned to the control group. Fecal materials, placental remains, and any other conspicuous dirt were removed from the single cow calving pens between each calving prior to the introduction of the next pregnant cow. The calves were then separated from their dams within 2h of birth. Multiple cow calving pens were managed as usual at the producers' discretion. Upon birth, the calf managers monitored each enrolled calf for signs of diarrhea, pneumonia plus other morbidity up to 90 d of age. The effects of single cow calving pens (vs. multiple cow calving pens) that are cleaned between calvings on the risk of neonatal calf diseases were evaluated using multivariable logistic regression models. Risk of diarrhea (OR=0.93, P=0.75), pneumonia (OR=1.23, P=0.64), and morbidity due to any cause (OR=0.93, P=0.74) were not significantly different between calves born in single cow vs. multiple cow calving pens. The current study found that, given the management situation evaluated, calves born in single cow calving pens were no different than calves born in multiple cow calving pens with respect to calf diseases risk. Long-term follow-up of the calves enrolled in the present study is ongoing to determine the efficacy of single cow calving pen use for the possible prevention of transmission of Mycobacterium avium subsp. paratuberculosis in Holstein calves.

The objective of this study was to characterize the antibody prevalence of important livestock and domestic animal pathogens in raccoons (Procyon lotor) trapped and sampled in 39 forest patches in north-central Indiana, USA, between 2004 and 2005. A total of 459 serum samples were tested for antibodies to Leptospira serovars, 512 for Canine distemper virus (CDV) antibodies, and 340 for antibodies to Porcine reproductive and respiratory syndrome virus (PRRSV). In total, 47, 16, and 0% of the samples were seropositive for at least one Leptospira serovar, CDV, and PRRSV, respectively. Most of the positive Leptospira results were to serovars grippotyphosa (36%), autumnalis (22%), and hardjo (22%). No statistically significant correlation was found between antibody prevalence estimates for different Leptospira serovars. A significant association was found between body weight and antibodies for Leptospira serovars and CDV. In addition, age (adult vs. juvenile) was significantly associated with the presence of CDV antibody, with adults exhibiting a higher prevalence than juveniles. This study confirmed that raccoons in Indiana, USA, are exposed to different Leptospira interrogans serovars and CDV and that age and weight are associated with the presence of antibodies for both pathogens.

We developed a stochastic simulation model to compare the herd sensitivity (HSe) of five testing strategies for detection of Mycobacterium avium subsp. paratuberculosis (Map) in Midwestern US dairies. Testing strategies were ELISA serologic testing by two commercial assays (EA and EB), ELISA testing with follow-up of positive samples with individual fecal culture (EAIFC and EBIFC), individual fecal culture (IFC), pooled fecal culture (PFC), and culture of fecal slurry samples from the environment (ENV). We assumed that these dairies had no prior paratuberculosis-related testing and culling. We used cost-effectiveness (CE) analysis to compare the cost to HSe of testing strategies for different within-herd prevalences. HSe was strongly associated with within-herd prevalence, number of Map organisms shed in feces by infected cows, and number of samples tested. Among evaluated testing methods with 100% herd specificity (HSp), ENV was the most cost-effective method for herds with a low (5%), moderate (16%) or high (35%) Map prevalence. The PFC, IFC, EAIFC and EBIFC were increasingly more costly detection methods. Culture of six environmental samples per herd yielded >or=99% HSe in herds with >or=16% within-herd prevalence, but was not sufficient to achieve 95% HSe in low-prevalence herds (5%). Testing all cows using EAIFC or EBIFC, as is commonly done in paratuberculosis-screening programs, was less likely to achieve a HSe of 95% in low than in high prevalence herds. ELISA alone was a sensitive and low-cost testing method; however, without confirmatory fecal culture, testing 30 cows in non-infected herds yielded HSp of 21% and 91% for EA and EB, respectively.

Our objectives were to identify associations between clinical or subclinical diseases and subsequent culling because of clinical Johne's disease (JD) or the detection of fecal shedding of Mycobacterium paratuberculosis (Map) after 305 days in milk (DIM). A total of 1297 cows from two Minnesota dairies were enrolled in the study. From study cows, fecal samples were obtained prior to calving (close-up period) and after at least 305 DIM or at the time of leaving the herd (sold/dead). Between 3 and 21 DIM, blood samples were obtained for serum betahydroxybutyrate (BHB) and serum total-protein testing. Body-condition score (BCS) was evaluated during the close-up period, between 3 and 21 DIM, and at the end of lactation. The diagnosis time (DIM) of clinical disease events (culling because of JD clinical signs, ketosis, lameness, mastitis, displacement abomasum, injury, metritis, milk fever, pneumonia, and retained placenta) was recorded. Sixty-six cows were culled because of JD clinical signs (CCDJ) with average DIM of 209. CCDJ was associated with event of pneumonia (n=131) (OR=3.0, 95% CI=1.0-6.0) and level of fecal shedding (light: OR=13.0, 95% CI=5.3-30.0; moderate: OR=34.0, 95% CI=13.0-89.0; heavy: OR=66.0, 95% CI=26.0-171.0). Detection of fecal shedding at the end of the lactation (n=79) was associated only with event of pneumonia (OR=2.0, 95% CI=1.0-4.0).

Lactation performance of cows infected with Mycobacterium avium subsp. paratuberculosis (Map) was previously studied using only serum ELISA as a diagnostic method. This study evaluated on two dairy farms in Minnesota, USA the lactation performance (measures of health, production, reproduction, and survival) of cows shedding Map in feces before calving and of cows culled with clinical signs consistent with Johne's disease (JD) during the subsequent lactation. Fecal samples were collected from 1052 cows within 21 day before calving and tested for Map with bacterial culture. Producers' observed signs of clinical disease (milk fever, retained placenta, metritis, ketosis, displaced abomasum, lameness, mastitis, pneumonia, and JD) and production and reproduction data were recorded for each cow. The association between fecal shedding or clinical JD and lactation performance was evaluated. Logistic regression was used to evaluate the association with any clinical and subclinical diseases as the outcome. General linear model was used to evaluate the association with milk production, and survival analysis techniques were used to evaluate the association with days in the study before culling and days from calving to conception. In 84 cows (8% of 1052 cows) fecal samples were positive for Map (46% light, 26% moderate, and 28% heavy shedders). In multivariable analysis, light, moderate, and heavy fecal shedding cows produced on average 537, 1403, and 1534 kg, respectively, less milk per lactation and 1.4, 5.2, and 7.5 kg, respectively, less milk per day than fecal negative cows. Fecal culture positive cows were less likely to be bred and conceive. In the multivariable analysis the 56 cows culled with presumed JD produced approximately 1500 kg/lactation or 5 kg/day less than all other cows. The negative economic impact implied by decreased lactation performance in cows shedding Map or with clinical JD may motivate producers to implement programs to control Map infection and subsequent JD.

The objectives of this study were to: (1) characterize Minnesota dairy herds participating in a Johne's disease control program (JDCP) based on herd size, milk production, and clinical Johne's disease (JD) history, (2) evaluate if change in farm management practices, expressed in risk assessment (RA) total score, is associated with the change between the first and most recent ELISA test herd seroprevalence or change in clinical JD culling rate, and (3) identify farm factors associated with ELISA seroprevalence. A total of 1234 RA, performed between January 2000 and February 2004, were available for analysis from 714 dairy herds. ELISA test results from herd sampling between 2000 and 2004 were obtained from the Minnesota board of animal health (MBAH) database, and were available for 474 herds. Both the first and the most recent ELISA test results for herds with more than one RA were available for 262 herds. Mean herd size and mean annual milk production per cow was higher in JDCP dairy herds (161 milking cows) than either all Minnesota dairy herds or Minnesota dairy herd improvement association (DHIA) herds. For herds with more than one RA available, the most recent RA total score was significantly lower (mean 11% less) than the first. The change in RA total score (and any RA subtotal scores) between the first and most recent RA was not associated with the change between the first and the most recent ELISA within-herd seroprevalence or the change in JD culling rate between the first and most recent RA. The most recent ELISA test results were positively associated with postweaned heifer score and JD culling rate. The RA score was not found to be an effective tool for the prediction of ELISA seroprevalence.

The objectives of this study were to estimate the prevalence of Mycobacterium avium subsp. paratuberculosis (MAP) among deer and rabbits surrounding infected and noninfected Minnesota dairy farms using fecal culture, and to describe the frequency that farm management practices were used that could potentially lead to transmission of infection between these species. Fecal samples from cows and the cow environment were collected from 108 Minnesota dairy herds, and fecal pellets from free-ranging white-tailed deer and eastern cottontail rabbits were collected from locations surrounding 114 farms; all samples were tested using bacterial culture. In addition, a questionnaire was administered to 114 herd owners. Sixty-two percent of the dairy herds had at least 1 positive fecal pool or environmental sample. A total of 218 rabbit samples were collected from 90% of the herds, and 309 deer samples were collected from 47% of the herds. On 2 (4%) of the farms sampled, 1 deer fecal sample was MAP positive. Both farms had samples from the cow fecal pool and cow environment that were positive by culture. On 2 (2%) other farms, 1 rabbit fecal sample was positive by culture to MAP, with one of these farms having positive cow fecal pools and cow environmental samples. Pasture was used on 79% of the study farms as a grazing area for cattle, mainly for dry cows (75%) and bred or prebred heifers (87%). Of the 114 farms, 88 (77%) provided access to drylot for their cattle, mainly for milking cows (77/88; 88%) and bred heifers (87%). Of all study farms, 90 (79%) used some solid manure broadcasting on their crop fields. Of all 114 farms, the estimated probability of daily physical contact between cattle manure and deer or rabbits was 20% and 25%, respectively. Possible contact between cattle manure and deer or rabbits was estimated to occur primarily from March through December. The frequency of pasture or drylot use and manure spreading on crop fields may be important risk factors for transmission of MAP among dairy cattle, deer, and rabbits. Although the MAP prevalence among rabbits and deer is low, their role as MAP reservoirs should be considered.

The objective of this study was to characterize the distribution of Mycobacterium paratuberculosis (Map) in the environment of infected and uninfected Minnesota dairy farms. Eighty herds known to be infected from Minnesota's Johne's Disease Control Program (JDCP) and 28 herds known to be uninfected from Minnesota Voluntary Johne's Disease Herd Status Program (VJDHSP) were sampled. Fecal samples from up to 100 cows in each herd were cultured in pools of 5 cows. Two environmental samples were obtained from each farm from various locations. All samples were tested using bacterial culture for Map. Eighty percent of the JDCP herds had at least one positive pool. Environmental samples were cultured positive in 78% of the JDCP herds. Two (7%) of the VJDHSP herds had one positive pool, and one herd had one positive environmental sample. Environmental samples were cultured positive in cow alleyways (77% of the herds), manure storage (68%), calving area (21%), sick cow pen (18%), water runoff (6%), and postweaned calves areas (3%). There was an association between maximum level of colonies per tube from cow alleyways and manure storage and fecal pool prevalence. Herds with both areas cultured negative were estimated to have 0.3 to 4% fecal pool prevalence. Herds with both areas having a heavy load of bacteria were estimated to have 53 to 73% fecal pool prevalence. The study results indicate that targeted sampling of cow alleyways and manure storage areas appears to be an alternative strategy for herd screening and Johne's infection status assessment and for estimating herd fecal prevalence.

Our objectives were to evaluate the effect of left displacement of abomasum (LDA) after correction by toggle-pin suture (TPS) on lactation performance, reproduction and health in Holstein dairy cows in a commercial dairy farm. Cows diagnosed with LDA and corrected by the TPS procedure (188 cows) during the first 70 d postpartum were matched with control herd-mates (186 controls) according to lactation number, calving date, and previous lactation 305-d mature equivalent milk yield. Cows were grouped according to parity and days in milk and fed the same total mixed ration throughout a 321-d lactation. Data collected included yields of milk and 3.5% fat-corrected milk (FCM), concentration and yields of milk fat, somatic cell count, incidence of mastitis, abortion, death and culling, in addition to reproductive measures. Cows affected with LDA corrected by the TPS procedure produced less milk and tended to produce less 3.5% FCM than control cows, but the decrease in production occurred only during the first 4 mo of lactation. Left displacement of abomasum did not affect the interval from calving to conception and conception rates, but it extended the period from calving to first postpartum artificial insemination. Incidences of abortions and mastitis were not influenced by LDA. Cows affected with LDA remained in the study for a shorter period than their control herdmates, and higher proportions of cows with LDA were sold or died. Death and culling were more pronounced immediately after the diagnosis of LDA and the TPS procedure.