An investigation of the effects of ketoprofen following rumen fistulation surgery in lactating dairy cows.

Post-operative pain management following rumen surgery is not common practice. We examined the effect of providing the pain medication ketoprofen to dairy cattle following the first stage of a rumen cannulation surgery, which involves an incision in the body wall and exteriorizing and clamping the rumen. The results of this study provide clear evidence that the first stage of the surgery was painful and ketoprofen at the time of and 24 h following surgery, alleviated some, but not all, of the post-surgical pain. Pain mitigation should be included when performing flank surgery in cattle.

Une enquête sur les effets du kétoprofène administré à des vaches laitières après une chirurgie de fistulisation du rumen. Ce n'est pas pratique courante d'administrer des analgésiques suite à la chirurgie du rumen. Cette étude a examiné les effets du médicament kétoprofène chez les vaches laitières après la première étape d'une chirurgie de fistulisation du rumen. Cette chirurgie consiste à faire une incision sur le côté gauche de l'abdomen pour ensuite sortir une partie du rumen de l'abdomen et de le fixer avec une attache. Les résultats de cette étude démontrent que la première étape était douloureuse et que l'administration du kétoprofène, à la fin de la chirurgie, ainsi qu'après 24 h, a atténué une partie de la douleur chirurgicale sans toutefois l'enlever complètement. L'administration d'analgésiques devrait faire partie intégrante du traitement lors des chirurgies abdominales chez les bovins.(Traduit par les auteurs).

Short communication: a comparison of 2 nonsteroidal antiinflammatory drugs following the first stage of a 2-stage fistulation surgery in dry dairy cows.

Postoperative pain and its management following fistulation surgery in cattle are poorly understood. The purpose of this study was to compare 2 nonsteroidal antiinflammatory drugs (NSAID) as potential postoperative pain management treatments following the first stage of a 2-stage fistulation surgery. A randomized complete block design trial was conducted in dry Holstein cows (n=10) following fistulation surgery. Ketoprofen (3mg/kg of body weight i.m.) was administered on the day of surgery and 24 h later, whereas meloxicam (0.5 mg/kg of body weight s.c.) was administered once only on the day of surgery. Outcomes evaluated at 0, 2, 9, 24, 26, and 33 h postsurgery were heart rate, respiration rate, rectal temperature, and infrared temperature around the surgical site. Outcomes evaluated on the day of surgery and d 1 following surgery and compared with the average for the 4d before surgery were lying activity (total lying time, total time spent lying on the left side, and percentage of time lying on the left side) and feed intake. A difference was observed in dry matter intake on d 1 but this effect was not different on d 0 compared with presurgical averages. A difference was observed in time spent lying on the left side and a difference was observed in heart rate following the first stage of fistulation surgery compared with presurgical averages. The infrared temperature readings around the surgical site were significantly greater in the hours following surgery compared with presurgical averages. The respiration rate increased over time after 24h postsurgery compared with presurgical values. Although it was clear that the surgery is painful, the drug effects were more difficult to explain. On d 0 and 1, the meloxicam-treated cows ate 3 kg more but spent 101 min/d less time lying on their left side compared with ketoprofen-treated cows. The first stage of a 2-stage fistulation surgery was considered painful based on changes in heart rate, respiration rate, infrared temperature readings, dry matter intake, and time spent lying on the left side. It is clear that left flank surgery is painful and that NSAID can improve outcomes associated with that pain, but we cannot make recommendations as to which NSAID to choose based on these results.

The effect of administering ketoprofen on the physiology and behavior of dairy cows following surgery to correct a left displaced abomasum.

Surgical correction of left displaced abomasum (LDA) is common in lactating dairy cattle. Despite the growing acceptance that abdominal surgery is painful, few cows are administered analgesia following LDA surgery. The objective of this research was to examine the effect of administering a label dose of ketoprofen on physiological and behavioral indicators of pain in dairy cattle. Holstein cows were enrolled in a field study following LDA surgery. Surgery was performed using the standing right flank (RF) approach or the paramedian (PARA) approach. Using a triple-blind randomized trial, each animal was assigned to receive either 3mg of ketoprofen/kg of body weight or saline (the equivalent volume) by intramuscular injection immediately following surgery and 24h postoperatively. Physiological parameters (heart rate, respiration rate, and rumen motility), blood ß-hydroxybutyrate (BHBA) levels, and an assessment of cow attitude were measured on the day of surgery, and at 2 follow-up visits (visit 1=3 ± 0.9 d and visit 2=9 ± 1.2 d postsurgery; n=175). Milk production and culling were recorded for all cows enrolled in the study. Producers assessed their cows' attitudes and appetites daily for the first 3 d following surgery. A subset of cows (n=37) were fitted on the day of surgery with a 3-axis accelerometer on the hind leg to assess lying behavior. Continuous and binary outcome data were analyzed using multivariable mixed linear and mixed logistic models, respectively, with cow modeled as a random effect. Ketoprofen did not alter the physiological measures, BHBA levels, or behavioral outcomes measured. Cows subjected to RF surgery had longer lying times [model coefficient ß=228.9 min; 95% confidence interval (CI): 122.2 to 335.6] in the first 3 d following surgery, and lower heart rates (ß=-9.4 beats/min; 95% CI: -12 to -6.9 beats/min) at the follow-up visits, compared with animals that underwent PARA surgery. Regardless of surgical procedure, BHBA decreased from surgery day to visit 1 (ß=-1.9 mmol/L; 95% CI: -2.1 to -1.7) and visit 2 (ß=-2.0 mmol/L; 95% CI: -0.2.2 to -1.8). Producer reports indicated that animals that received ketoprofen were more likely to begin eating when provided fresh feed during the first 3 d following surgery compared with those that received saline (odds ratio=4.8; 95% CI: 0.97 to 23.8). These results indicate that PARA surgery may be more painful relative to lying down than the RF approach. The apparent differences in appetite or attitude in cows that received ketoprofen reported by producers warrant further investigation.

Effects of meloxicam on milk production, behavior, and feed intake in dairy cows following assisted calving.

Parturition is a necessary event for production in dairy cattle, and assistance at calving is common. There is limited use of nonsteroidal antiinflammatory drugs for the alleviation of calving pain and a paucity of research on the effects of these drugs on postpartum health and performance. This randomized triple blind clinical trial involved Holstein cows (n=42) and heifers (n=61) that experienced an assisted parturition. These animals received either 1 injection of meloxicam (0.5mg/kg of body weight) or placebo subcutaneously 24h following calving. Outcome measures included dry matter intake (DMI) and milk production for the first 14d in milk, blood metabolites sampled over 12d, health events for the first 60d in milk, as well as lying and feeding behavior 24h following injection. Continuous data were analyzed using multivariable regression models. Binary outcomes were analyzed using a mixed logistic model with cow modeled using a random intercept. This study failed to show any significant effects of treatment on DMI, milk production, blood metabolites, or health events. A possible explanation for the lack of treatment differences could be that the meloxicam was administered too late after calving. Meloxicam increased feeding time as well as bunk visit frequency in the 24h following injection. Regardless of treatment, animals that had retained fetal membranes produced less milk and had higher serum haptoglobin concentrations. Future research is warranted to examine the effects of antiinflammatory drugs administered closer to the time of calving on health and production.

Short communication: use of a mechanical brush by Holstein dairy cattle around parturition.

Grooming is a normal behavior that may contribute to relief of stress. The purpose of this study was to investigate the effect of access to a mechanical brush on auto-grooming behavior in parturient cows. The hypothesis was that cows would increase the total time spent scratching using the brush if they had access to a brush around the time of calving, whereas auto-grooming would be lower for the brush group compared with the no-brush group. The use of a mechanical brush was analyzed both in a group-housed pen (72 to 48 h before calving) and in an individual maternity pen (6h before to 6h after calving) in 16 multiparous Holstein cows. In the maternity pen, cows were randomly assigned to have access to the brush or not. The provision of a mechanical brush in the individual maternity pen did not change the amount of time spent auto-grooming but cows did use the brush before calving and after the calf was removed. Despite being housed in pens containing a brush, cows failed to use it when the calf was present. However, cows with access to a brush spent more time licking their calves in the first hour postcalving (ß=8.7 min; 95% confidence interval: 1.5, 15.8) than cows that did not have access to a brush. Regardless of treatment, cows increased the time spent auto-grooming and scratching following separation of their newborn calf (ß=1.4 min; 95% confidence interval: 0.46, 2.3 and ß=0.07 min; 95% confidence interval: 0.02, 0.12, respectively). Further research is warranted to investigate possible benefits of mechanical brush devices at the time of calving, particularly for cows that experience difficult calving and require manual or mechanical assistance.

Evaluation of prepartum serum cholesterol and fatty acids concentrations as predictors of postpartum retention of the placenta in dairy cows.

OBJECTIVE: To identify serum biochemical and hematologic variables, as measured in the week before parturition, that predict postpartum retention of the placenta (RP) in dairy cows. DESIGN: Retrospective cohort study. ANIMALS: 1,038 cows in 20 commercial dairy herds. PROCEDURES: Serum concentrations of fatty acids (FAs), beta-hydroxybutyrate, cholesterol, glucose, urea, and calcium and blood leukocyte, neutrophil, lymphocyte, monocyte, and eosinophil counts were determined. These variables were evaluated for an association with development of RP by use of a multivariate logistic regression model. Parity, season of parturition, existence of twins or dystocia, body condition score, and vitamin E treatment were included in the model as covariates. RESULTS: High serum concentrations of cholesterol and FAs were associated with an increased odds of RP. There was a 5% relative increase in the odds of RP for each 0.1 mmol/L increase in cholesterol or FAs concentration in the week before parturition. Season of parturition and twinning were also identified as risk factors. CONCLUSIONS AND CLINICAL RELEVANCE: These associations indicated that prepartum energy metabolism contributes to the development of RP. Serum concentrations of cholesterol and FAs may be useful to identify cows with a metabolic abnormality or energy imbalance that might predispose them to RP and should be interpreted in conjunction with clinical risk factors such as twinning, dystocia, or parturient paresis.

Reference limits for biochemical and hematological analytes of dairy cows one week before and one week after parturition.

Since dairy cows during the transition period have multiple endocrine and metabolic changes, it is necessary to determine the reference limits of laboratory analytes in normal transition cows. Reference limits for the weeks before and after calving were determined in dairy cows. Animals that had adverse clinical outcomes after calving and cows that were culled or had mastitis within the first 7 days after calving were excluded. All biochemical analytes (beta-hydroxybutyrate, fatty acids, glucose, cholesterol, urea, calcium, and phosphorus) were statistically different between precalving and postcalving groups. The hematological analytes were not significantly different except for eosinophils. The data from precalving and postcalving cows were significantly different from reference limits in a university-associated laboratory derived from early- and mid-lactation cows. Different reference limits for precalving and postcalving dairy cows should be determined for biochemical analytes to ensure appropriate interpretation of results.

Characterization of bacterial populations recovered from the teat canals of lactating dairy and beef cattle by 16S rRNA gene sequence analysis.

Bovine mastitis is of major concern to the dairy industry worldwide. The bovine teat canal is the primary route through which pathogens enter the mammary gland. The microflora of the teat canals of dairy and beef cattle was investigated by analysis of 16S rRNA gene sequences. The goal was to examine the global difference between dairy cattle, which are sanitized on a regular basis, and beef cattle, which receive little sanitary management. A diverse population of 16S rRNA gene sequences was recovered from both the dairy and the beef herd samples, with diversity higher in the beef sample. Analysis revealed the presence of 90 operational taxonomic units (OTUs) among 156 sequences, with 45 OTUs in the dairy sample and 53 OTUs in the beef sample. Only eight OTUs were common to both samples. Members of the classes Clostridia and Bacilli dominated both samples, followed by Actinobacteria and Proteobacteria. The dairy sample contained a cluster (20/80 clones) of Staphylococcaceae members, seven of which were identifiable as coagulase-negative Staphylococcus species. The beef sample was dominated by members of the genus Clostridia, many of which have not been previously cultured. The results suggest that the microorganisms present in the bovine teat canal are more diverse than previously described.

Efficacy of monensin sodium for the reduction of fecal shedding of Mycobacterium avium subsp. paratuberculosis in infected dairy cattle.

Reducing the quantity of Mycobacterium avium subsp. paratuberculosis (MAP) being shed by cows with Johne's disease should decrease the risk of spread of this disease to young stock. Previous work has suggested that monensin sodium decreases the pathologic lesions associated with Johne's disease, but the impact on shedding of viable MAP remains unknown. After serologic screening of 32 dairy herds in southwestern Ontario, 228 cows from 13 of these herds were enrolled into a randomized clinical trial. Fecal culture and PCR were used to identify 114 cows as potential fecal shedders, while another 114 cows were enrolled as ELISA negative, herd and parity matched controls. All cows were randomized to receive either a monensin controlled release capsule (CRC) or a placebo capsule. Serial fecal and blood samples were collected for fecal culture and serum ELISA testing over a 98-day period. On day 98 of the study, treatments were switched for all cows continuing in the trial. These remaining cows were followed for another 98 days with a similar sampling protocol. Mixed effect models were used to measure the impact of treatment on the number of colony forming units identified on fecal cultures over time. During the first 98 days of the study, cows treated with a monensin CRC were found to shed 3.4cfu per tube less than placebo treated cows (P=0.05). The serum ELISA S/P ratio was reduced by 1.39 units in cows given monensin (P=0.06). However, treatment with monensin did not reduce the odds of testing positive on serology. Only the cows shedding MAP on day 0 were found to have a reduced odds of testing positive on fecal culture when treated with monensin (OR=0.27; P=0.03). Monensin sodium administered to infected animals at 335mg/day marginally reduced fecal shedding of MAP in mature dairy cattle, but the biological significance of this reduction is unknown.

Monensin might protect Ontario, Canada dairy cows from paratuberculosis milk-ELISA positivity.

Our objective was to define the role of monensin sodium in protecting cows from being milk-ELISA positive for paratuberculosis in Ontario, Canada dairy herds. In total, 4933 dairy cows from 94 herds were enrolled in this cross-sectional study. Forty-four of the enrolled herds were selected purposively by their herd veterinarian and another 50 herds were randomly selected from a local milk production-recording agency. A herd-management survey was completed on each farm during the months of May through August 2003. During this same time-period, composite milk samples were collected from all lactating cows and tested with a milk-ELISA for antibodies to Mycobacterium avium subspecies paratuberculosis. Analyses were stratified according to the paratuberculosis history of the herds. In the 48 herds in which paratuberculosis had not been diagnosed before, the use of calf hutches and monensin in milking cows were both associated with reduced odds of a cow testing positive (OR=0.19 and 0.21, respectively). In the 46 herds with a prior history of paratuberculosis, feeding monensin to the breeding-age heifers was associated with decreased odds of a cow testing positive (OR=0.54). Monensin use might be associated with milk-ELISA positivity, but its impact on the transmission of paratuberculosis remains unknown.

Influence of the genotype of Staphylococcus aureus, determined by pulsed-field gel electrophoresis, on dry-period elimination of subclinical mastitis in Canadian dairy herds.

By combining information from 2 databases, we investigated the possibility of an association between the genotype of Staphylococcus aureus causing bovine intramammary infection and dry-period cure of subclinical infection. The 1st database contained bacteriologic and cow data from a field study evaluating the efficacy in such infections of a new intramammary dry-cow therapy (DCT) containing tilmicosin phosphate, in comparison with a commercially available DCT containing benzathine cloxacillin. Isolates of S. aureus from that study were frozen and later independently analyzed by pulsed-field gel electrophoresis (PFGE) and macrorestriction DNA fingerprinting. The molecular information, summarized and published elsewhere, constituted the 2nd database. Data from 121 subclinically infected quarters of 92 cows from 40 herds were studied by univariate and multivariable regression analysis. Infection by an isolate of PFGE lineage group D was more likely than infection by an isolate of group A or F to be cured (P < 0.05). Cows infected by lineage group D had a higher linear somatic cell count score (LS) from the last Dairy Herd Improvement test before the dry period than did cows infected by the other lineage groups (P = 0.04). Although the probability of cure was significantly lower for cows with an LS at or above the mean of 5.7 for the study population (P = 0.05), when such a cow was infected with lineage group D, cure was significantly more likely (P < 0.001) than when it was infected by another lineage group. Significantly more (P = 0.02) of the infections treated with tilmicosin (74%) than of those treated with benzathine cloxacillin (53%) were cured, and significantly more (P = 0.05) of the infections by group D (81%) than of those by group A (57%) or group F (54%) were cured. However, there was no difference in cure rate for any PFGE genotype when tilmicosin phosphate was administered; when benzathine cloxacillin was administered, 87% of lineage group D isolates were eliminated, as compared with 46% of group A and 33% of group F isolates (P < 0.05). This research demonstrates that certain genotypes of S. aureus may naturally elicit a greater inflammatory response, yet be more susceptible to elimination by antibiotics in the dry period, than other genotypes.

Assessment of antimicrobial transfer from treated to untreated mammary gland quarters by use of high-pressure liquid chromatography for detection of cloxacillin in milk samples from nonlactating dairy cows.

OBJECTIVE: To determine whether half-udder intramammary infusion of cloxacillin results in transfer of cloxacillin from treated to untreated mammary gland quarters within nonlactating cows, and, if so, at what concentrations, and to determine whether selection of ipsilateral versus diagonal-contralateral quarters for treatment affects cloxacillin transfer among quarters. ANIMALS: 20 Holstein-Friesian cows from a dairy herd. PROCEDURES: A within-cow half-udder comparison trial was used in which 2 of 4 mammary gland quarters (ipsilaterally or diagonally) received an intramammary infusion of cloxacillin on day 1 of the nonlactating period. Three days later, milk samples were taken from all untreated quarters and high-pressure liquid chromatography was used to detect and quantify milk cloxacillin concentrations. RESULTS: Cloxacillin was detected in 25% of all untreated mammary gland quarters. Mean cloxacillin concentration in untreated quarters was below minimum inhibitory concentrations for targeted mastitis pathogens. No significant difference in cloxacillin concentrations was found in the ipsilateral or diagonal treatment groups. CONCLUSIONS AND CLINICAL RELEVANCE: Within-cow half-udder comparison trials are valid for antimicrobial trials in nonlactating cows, although transfer of antimicrobials does occur in trace concentrations. Ipsilateral or diagonal-contralateral treatment designs perform similarly. This type of design is economical for researchers, although care must be taken to account for within-cow clustering of mammary gland quarter data.

Efficacy of using an internal teat sealer to prevent new intramammary infections in nonlactating dairy cattle.

OBJECTIVE: To determine whether insertion of an internal teat sealer (ITS) at the end of lactation would prevent development of new intramammary infections (IMIs) during the nonlactating period. DESIGN: Controlled clinical trial. ANIMALS: 939 Holstein-Friesian dairy cows from 16 herds. PROCEDURES: Results of bacteriologic culture of milk samples collected 14 days prior to the end of lactation were used to assign cows to groups (group 1 = negative results for all quarters; group 2 = positive results for > or = 1 quarter). Quarters of cows in group 1 were treated with an ITS or a single intramammary dose of cloxacillin; quarters of cows in group 2 were treated with cloxacillin in conjunction with an ITS or with cloxacillin alone. Milk samples were collected at the end of lactation and within 8 days after calving. RESULTS: Regardless of whether the outcome of interest was new IMIs caused by any pathogens, major pathogens, environmental pathogens, or streptococci other than Streptococcus agalactiae, quarters in group 2 treated with both cloxacillin and an ITS were less likely to develop a new IMI than were quarters treated with cloxacillin alone. For cows in group 1, no significant difference in risk of new IMIs was found between treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that for dairy cattle with an IMI late in the lactation period, intramammary administration of cloxacillin at the end of lactation followed by insertion of an ITS enhanced protection against development of new IMIs, compared with use of cloxacillin alone.

A comparison of serum harvesting methods and type of refractometer for determining total solids to estimate failure of passive transfer in calves.

Monitoring the passive transfer of immunoglobulins from colostrums particularly in noncentrifuged samples can be useful for calf health management programs. The results of total solids refractometry from centrifuge and noncentrifuge harvested sources of serum were highly correlated (R2 = 0.95). Results from a digital and a hand-held refractometer were highly correlated (R2 = 0.96).

The relationship between herd level disease incidence and a return over feed index in Ontario dairy herds.

The objective of the current research was to examine the association of herd level disease incidence with the return over feed (ROF) (milk income minus feed cost) herd profit index offered through Canwest Dairy Herd Improvement. The lactational incidence risks (LIR) for displaced abomasum, retained placenta, clinical mastitis, milk fever, clinical ketosis, and lameness submitted by producers (n = 48) were similar to previous reports. However, there was no negative association of clinical disease LIR's with ROE Subclinical ketosis and subclinical mastitis cumulative incidence were determined during the early postpartum period by using a cow-side test for betahydroxybutyrate in milk and the California Mastitis Test, respectively. Subclinical mastitis was not associated with ROE However, a unit increase in the cumulative incidence of subclinical ketosis was associated with a decrease of dollars 0.015/cow/day in the ROE The results highlight the economic significance that subclinical ketosis may have in Ontario dairy herds.

The impact of controlled release capsules of monensin on postcalving haptoglobin concentrations in dairy cattle.

This study was designed to assess the impact of a controlled release capsule (CRC) of monensin, administered prior to calving, on postcalving haptoglobin levels. The role of disease on haptoglobin levels was also studied. The study population consisted of 1010 cows from 25 Holstein dairy herds near Guelph, Ontario. Monensin CRC or placebo capsules were randomly assigned within each herd 3 wk prior to the expected calving date. Serum from week 1 and week 6 postcalving was submitted for quantification of haptoglobin concentrations. Haptoglobin results were analyzed for associations with treatment, health data, and individual cow factors up to 95 d in milk. Haptoglobin concentrations were higher in week 1 than week 6 (P < 0.05). In univariate analysis, several diseases were significantly associated with haptoglobin concentrations. However, occurrence of disease appeared to be a confounding factor in the data interpretation. Thus, the analysis was stratified by the presence or absence of disease. There appeared to be associations between factors other than clinical disease contributing to increased haptoglobin levels in both clinically healthy and unhealthy cattle. Haptoglobin served as a good indicator of inflammatory disease. Monensin CRC treatment was associated with increased haptoglobin concentrations in clinically unhealthy cattle, perhaps reflecting a better ability to respond to disease challenge. The lower haptoglobin concentrations in monensin CRC treated cattle that were clinically normal may be a reflection of reduced subclinical disease.

Evaluation of enzyme-linked immunosorbent assays performed on milk and serum samples for detection of paratuberculosis in lactating dairy cows.

OBJECTIVE: To determine whether results obtained for milk and serum samples with ELISAs intended for diagnosis of paratuberculosis in dairy cows were comparable to results obtained by means of mycobacterial culture of fecal samples. DESIGN: Cross-sectional study. ANIMALS: 689 lactating dairy cows in 9 Ontario herds. PROCEDURE: Milk, serum, and fecal samples were obtained from all cows. Fecal samples were submitted for mycobacterial culture. Serum samples were tested with a commercially available ELISA for antibodies against Mycobacterium paratuberculosis, and preserved milk samples were tested with an indirect ELISA for antibodies against M paratuberculosis. RESULTS: Results were positive for 130 of the 689 (18.9%) serum samples, 77 of the 689 (11.1%) milk samples, and 72 of the 689 (10.4%) fecal samples. The level of agreement between results for milk and serum samples was only moderate. Proportions of positive results for serum and fecal samples were significantly different, but proportions of positive results for milk and fecal samples were not significantly different. In addition, results for milk samples had a higher level of agreement with results of mycobacterial culture than did results for serum samples. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the indirect ELISA used on milk samples may be a convenient method of detecting paratuberculosis in dairy herds.

Effect of paratuberculosis on culling, milk production, and milk quality in dairy herds.

OBJECTIVE: To determine the effect of paratuberculosis on culling, milk production, and milk quality in infected dairy herds. DESIGN: Cross-sectional study. ANIMALS: 689 lactating dairy cows in 9 herds. PROCEDURE: Milk, blood, and fecal samples were obtained from all cows. Fecal samples were evaluated via mycobacterial culture. Serum samples were tested with a commercially available ELISA for antibodies against Mycobacterium avium subsp paratuberculosis, and preserved milk samples were tested with an ELISA for antibodies against M paratuberculosis. Mixed effect and proportional hazards models were used to determine the effect of paratuberculosis on 305-day milk, fat, and protein production; somatic cell count linear score; and the risk of culling. RESULTS: Cows with positive results of bacteriologic culture of feces and milk ELISA produced less milk, fat, and protein, compared with herdmates with negative results. No difference in 305-day milk or fat production was detected in cows with positive results of serum ELISA, compared with seronegative cows. The 3 survival analyses revealed that cows with positive results of each test were at higher risk of being culled than cows with negative results. Paratuberculosis status, as determined by use of all 3 diagnostic tests, was not associated with milk somatic cell count linear score. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that for the 9 herds in this study, paratuberculosis significantly decreased milk production and cow longevity.

A comparison of the cytobrush and uterine lavage techniques to evaluate endometrial cytology in clinically normal postpartum dairy cows.

This study compares cytobrush and lavage techniques for the assessment of endometrial cytology (EC) in clinically normal postpartum dairy cows. The EC samples were collected from Holstein cows (n = 35) during visit 1 (V1) at 20 to 33 d in milk (DIM) and 2 wk later during visit 2 (V2) at 34 to 47 DIM by using both techniques. A minimum of 100 cells were counted to determine the percentage of cells that were neutrophils (%PMN). The mean %PMN was significantly different between the techniques at V1 (P = 0.001), but not at V2 (P = 0.474). Overall, the %PM N decreased with time postpartum (r2 = 0.36; P = 0.001), but not within V1 (P > 0.05) or V2 (P > 0.1). Uterine diameter was negatively correlated with fluid recovery by the lavage technique (r2 = 0.41; P = 0.002). The mean %PMN was not influenced by the volume of fluid recovered in successful attempts, but 17% (12/70) of attempts yielded no fluid. In conclusion, the cytobrush technique is a consistent and reliable method for obtaining endometrial samples for cystologic examination from postpartum dairy cows.

Association of bovine respiratory disease or vaccination with serologic response in dairy heifer calves up to three months of age.

OBJECTIVE: To investigate the association of bovine respiratory disease (BRD) or vaccination with serologic response in calves. ANIMALS: 94 Holstein calves. PROCEDURES: To assess the association between BRD and antibody titers, 38 calves < 3 months old that were treated for BRD were matched with 38 untreated calves. To investigate the effect of vaccination on antibody titers, 24 calves were randomly assigned to be vaccinated against bovine respiratory syncytial virus (BRSV), bovine viral diarrhea virus types 1 and 2, bovine herpesvirus type 1 (BHV1), and parainfluenza virus type 3 at 2 weeks of age (n = 6), 5 weeks of age (6), and both 2 and 5 weeks of age (6) or were assigned to be unvaccinated controls (6). Blood samples were obtained at I, 2, 5, and 12 weeks for determination of serum neutralization antibody titers against the vaccine viruses, bovine coronavirus, and Mannheimia haemolytica. Antibody rates of decay were calculated. RESULTS: Calves with initial antibody titers against BRSV < 1:64 that were treated for BRD had a slower rate of anti-BRSV antibody decay than did similar calves that were not treated for BRD. Calves with high initial antibody titers against BRSV and BHV1 had lower odds of BRD than did calves with low initial antibody titers against those 2 pathogens. Vaccination at 2 or 5 weeks of age had no effect on the rate of antibody decay. CONCLUSIONS AND CLINICAL RELEVANCE: Clinical BRD and the serologic response of dairy calves were associated with initial antibody titers against BRSV and BHV1. Serologic or clinical responses to viral exposure may differ in calves with low passive immunity.