Gap between producers and veterinarians regarding biosecurity on Quebec dairy farms.

As part of the ProAction on-farm program to implement national biosecurity requirements on dairy farms, Canadian veterinarians are called upon to complete biosecurity risk assessments. The objective of the present study was consequently to understand veterinarians' perceptions of biosecurity, and to compare perceptions among producer-veterinarian pairs. Questionnaires were administered to 106 producers from Quebec and their veterinarians (n = 82), and the answers of the producer-veterinarian pairs were compared. While most veterinarians reported it was easy to discuss biosecurity with their clients, most veterinarians and producers did not report discussing biosecurity. Moreover, when producers or veterinarians reported discussing biosecurity topics, there was no agreement amongst pairs. Veterinarians also misjudged how their clients perceived the importance and usefulness of biosecurity. Finally, veterinarians reported they had the knowledge and opportunity to assess and discuss biosecurity on dairy farms but lacked skills for evaluating farms and communicating their knowledge.

Différences entre les producteurs et les vétérinaires en matière de biosécurité dans les fermes laitières du Québec. Dans le cadre du programme à la ferme ProAction visant à mettre en oeuvre les exigences nationales de biosécurité dans les fermes laitières, les vétérinaires canadiens sont appelés à effectuer l'évaluation des risques reliés à la biosécurité. L'objectif de cette étude était, par conséquent, de comprendre la perception qu'ont les vétérinaires de la biosécurité et de comparer cette perception entre les paires producteurs-vétérinaires. Des questionnaires ont été administrés à 106 producteurs québécois et à leurs vétérinaires (n = 82). Les réponses des paires producteurs-vétérinaires ont été comparées. Alors que la plupart des vétérinaires ont déclaré qu'il était facile de discuter de biosécurité avec leurs clients, la plupart des vétérinaires et des producteurs n'ont pas déclaré en avoir discuté dans l'année précédant l'étude. De plus, lorsque les producteurs ou les vétérinaires ont rapporté avoir discuté de sujets liés à la biosécurité, il n'y avait pas d'accord entre les paires. Les vétérinaires ont également mal évalué la façon dont leurs clients percevaient l'importance et l'utilité des mesures de biosécurité. Enfin, les vétérinaires ont indiqué qu'ils avaient les connaissances et la possibilité d'évaluer et de discuter de la biosécurité dans les exploitations laitières, mais manquaient de compétences pour évaluer les exploitations et communiquer leurs connaissances.(Traduit par Dr José Denis-Robichaud).

Herd-Level Mastitis-Associated Costs on Canadian Dairy Farms.

Mastitis imposes considerable and recurring economic losses on the dairy industry worldwide. The main objective of this study was to estimate herd-level costs incurred by expenditures and production losses associated with mastitis on Canadian dairy farms in 2015, based on producer reports. Previously, published mastitis economic frameworks were used to develop an economic model with the most important cost components. Components investigated were divided between clinical mastitis (CM), subclinical mastitis (SCM), and other costs components (i.e., preventive measures and product quality). A questionnaire was mailed to 374 dairy producers randomly selected from the (Canadian National Dairy Study 2015) to collect data on these costs components, and 145 dairy producers returned a completed questionnaire. For each herd, costs due to the different mastitis-related components were computed by applying the values reported by the dairy producer to the developed economic model. Then, for each herd, a proportion of the costs attributable to a specific component was computed by dividing absolute costs for this component by total herd mastitis-related costs. Median self-reported CM incidence was 19 cases/100 cow-year and mean self-reported bulk milk somatic cell count was 184,000 cells/mL. Most producers reported using post-milking teat disinfection (97%) and dry cow therapy (93%), and a substantial proportion of producers reported using pre-milking teat disinfection (79%) and wearing gloves during milking (77%). Mastitis costs were substantial (662 CAD per milking cow per year for a typical Canadian dairy farm), with a large portion of the costs (48%) being attributed to SCM, and 34 and 15% due to CM and implementation of preventive measures, respectively. For SCM, the two most important cost components were the subsequent milk yield reduction and culling (72 and 25% of SCM costs, respectively). For CM, first, second, and third most important cost components were culling (48% of CM costs), milk yield reduction following the CM events (34%), and discarded milk (11%), respectively. This study is the first since 1990 to investigate costs of mastitis in Canada. The model developed in the current study can be used to compute mastitis costs at the herd and national level in Canada.

Quantification of bovine immunoglobulin G using transmission and attenuated total reflectance infrared spectroscopy.

In this study, we evaluated and compared the performance of transmission and attenuated total reflectance (ATR) infrared (IR) spectroscopic methods (in combination with quantification algorithms previously developed using partial least squares regression) for the rapid measurement of bovine serum immunoglobulin G (IgG) concentration, and detection of failure of transfer of passive immunity (FTPI) in dairy calves. Serum samples (n = 200) were collected from Holstein calves 1-11 days of age. Serum IgG concentrations were measured by the reference method of radial immunodiffusion (RID) assay, transmission IR (TIR) and ATR-IR spectroscopy-based assays. The mean IgG concentration measured by RID was 17.22 g/L (SD ±9.60). The mean IgG concentrations predicted by TIR and ATR-IR spectroscopy methods were 15.60 g/L (SD ±8.15) and 15.94 g/L (SD ±8.66), respectively. RID IgG concentrations were positively correlated with IgG levels predicted by TIR (r = 0.94) and ATR-IR (r = 0.92). The correlation between 2 IR spectroscopic methods was 0.94. Using an IgG concentration <10 g/L as the cut-point for FTPI cases, the overall agreement between TIR and ATR-IR methods was 94%, with a corresponding kappa value of 0.84. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for identifying FTPI by TIR were 0.87, 0.97, 0.91, 0.95, and 0.94, respectively. Corresponding values for ATR-IR were 0.87, 0.95, 0.86, 0.95, and 0.93, respectively. Both TIR and ATR-IR spectroscopic approaches can be used for rapid quantification of IgG level in neonatal bovine serum and for diagnosis of FTPI in dairy calves.

A rapid field test for the measurement of bovine serum immunoglobulin G using attenuated total reflectance infrared spectroscopy.

BACKGROUND: Following the recent development of a new approach to quantitative analysis of IgG concentrations in bovine serum using transmission infrared spectroscopy, the potential to measure IgG levels using technology and a device better designed for field use was investigated. A method using attenuated total reflectance infrared (ATR) spectroscopy in combination with partial least squares (PLS) regression was developed to measure bovine serum IgG concentrations. ATR spectroscopy has a distinct ease-of-use advantage that may open the door to routine point-of-care testing. Serum samples were collected from calves and adult cows, tested by a reference RID method, and ATR spectra acquired. The spectra were linked to the RID-IgG concentrations and then randomly split into two sets: calibration and prediction. The calibration set was used to build a calibration model, while the prediction set was used to assess the predictive performance and accuracy of the final model. The procedure was repeated for various spectral data preprocessing approaches. RESULTS: For the prediction set, the Pearson's and concordance correlation coefficients between the IgG measured by RID and predicted by ATR spectroscopy were both 0.93. The Bland Altman plot revealed no obvious systematic bias between the two methods. ATR spectroscopy showed a sensitivity for detection of failure of transfer of passive immunity (FTPI) of 88 %, specificity of 100 % and accuracy of 94 % (with IgG <1000 mg/dL as the FTPI cut-off value). CONCLUSION: ATR spectroscopy in combination with multivariate data analysis shows potential as an alternative approach for rapid quantification of IgG concentrations in bovine serum and the diagnosis of FTPI in calves.

Measurement of serum immunoglobulin G in dairy cattle using Fourier-transform infrared spectroscopy: a reagent free approach.

Simple, rapid and cost-effective methods are sought for measuring immunoglobulin G (IgG) concentrations in bovine serum, which can be applied for diagnosis of failure of transfer of passive immunity (FTPI). The aim of the present study was to investigate the potential use of Fourier-transform infrared (FTIR) spectroscopy, with partial least squares (PLS) regression, to measure IgG concentrations in bovine serum. Serum samples collected from calves and adult cows were tested in parallel by radial immunodiffusion (RID) assay and FTIR spectroscopy. The sample IgG concentrations obtained by the RID method were linked to pre-processed spectra and divided into two sets: a combined set and a test set. The combined set was used for building a calibration model, while the test set was used to assess the predictive ability of the calibration model, resulting in a root mean squared error of prediction (RMSEP) of 307.5 mg/dL. The concordance correlations between the IgG measured by RID and predicted by FTIR spectroscopy were 0.96 and 0.93 for the combined and test data sets, respectively. Analysis of the data using the Bland-Altman method did not show any evidence of systematic bias between FTIR spectroscopy and RID methods for measurement of IgG. The clinical applicability of FTIR spectroscopy for diagnosis of FTPI was evaluated using the entire data set and showed a sensitivity of 0.91 and specificity of 0.96, using RID as the reference standard. The FTIR spectroscopy method, described in the present study, demonstrates potential as a rapid and reagent-free tool for quantification of IgG in bovine serum, as an aid to diagnosis of FTPI in calves.

Bulk tank milk selenium and its association with milk production parameters in Canadian dairy herds.

An observational study was conducted in 63 Canadian dairy farms to evaluate the association of bulk tank milk selenium (Se) concentration (BTSe) with average daily milk yield, milk fat and milk protein, bulk tank somatic cell count (BTSCC), and the probability of being a Staphylococcus aureus-positive herd. Bulk tank milk samples collected between March 2007 and February 2008 were evaluated for BTSCC, S. aureus culture status, and BTSe. Mean BTSe was 0.51 ± 0.15 µmol/L; no herds were classified as deficient or marginal based on BTSe. Bulk tank milk Se was unconditionally associated with milk production; however, adjusting by region indicated a confounding effect of this variable. There was no relationship between BTSe and BTSCC. Higher values of BTSe were associated with lower risk of being a S. aureus-positive herd, possibly as a result of a more robust udder immune response, or as a result of providing Se at a higher rate as one component of an udder health program that reduces risk of being S. aureus positive.

Prevalence of contagious mastitis pathogens in bulk tank milk in Prince Edward Island.

The purpose of this study was to 1) estimate the herd prevalence of contagious mastitis pathogens in bulk milk from Prince Edward Island (PEI) dairy farms, 2) determine the association between bulk milk culture results and mean bulk milk somatic cell count (BMSCC), and 3) investigate the agreement of repeated bulk milk cultures. Three consecutive bulk milk samples were obtained at weekly intervals from all 258 PEI dairy herds and were cultured using routine laboratory methods. Cumulative prevalence of Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma spp. (M. bovis and M. alkalescens) was 74%, 1.6%, and 1.9%, respectively. Bulk milk somatic cell count of Staph. aureus-positive herds was higher than that of negative herds. Agreement for Staph. aureus isolation between 3 consecutive tests was moderate (kappa = 0.46). Mycoplasma bovis and M. alkalescens in bulk milk are being reported for the 1st time in PEI ever and in Canada since 1972.

Monensin toxicosis in a dairy herd.

An acute onset of illness was reported in a lactating dairy herd in Canada in which monensin had been incorporated in error in its ration at almost 10 times the prescribed level. All of the lactating cows became lethargic, were inappetant, developed diarrhea, and had decreased milk production from 28 kg/cow/day, the day before exposure, to 23 kg/cow/day, 3 d later. Within 9 d, all animals recovered from the incident and milk production returned to previous levels.

The selenium status of dairy herds in Prince Edward Island.

Bulk tank milk selenium (Se) concentration was compared with mean serum Se concentration in 15 herds and was found to be an accurate reflection of the herd Se status. The Se status of 109 Prince Edward Island (PEI) dairy herds was monitored for 1 year using bulk tank milk Se concentration. Fifty-nine percent of the herds surveyed were, at some point, found to be marginal or deficient in Se, putting them at risk of disease and suboptimal production. The periods of greatest risk of deficiency were fall and winter, at which time 5% and 4%, respectively, of herds sampled fell in the range considered truly deficient in Se. Herds in which Se supplementation was provided in the form of a commercial dairy concentrate were over 4 times more likely to be Se-adequate than herds not using this method, and adjusted average daily milk yield was 7.6% greater in herds determined to be Se-adequate when compared with Se-marginal herds. We conclude that many dairy producers in PEI are providing insufficient supplementary Se in the ration to meet the recommended Se intake for lactating cows.

Management factors related to seroprevalences to bovine viral-diarrhoea virus, bovine-leukosis virus, Mycobacterium avium subspecies paratuberculosis, and Neospora caninum in dairy herds in the Canadian Maritimes.

Bovine viral-diarrhoea (BVD), enzootic bovine leukosis (EBL), Johne's disease (JD), and neosporosis lower on-farm productivity, reduce export competitiveness, and increase consumer concerns regarding safety. Our purpose was to examine the relationship between 27 control practices and the estimated true seroprevalences for these four diseases for 2604 cattle in 90 dairy herds in the Maritimes provinces of Canada. Overall, 37.8, 20.4, 3.4, and 19.2% of all sampled cattle were truly exposed to the agents of BVD, EBL, JD, and neosporosis, respectively. The median within-herd true prevalences were 0, 9.3, 0, and 12.3%, respectively. Factor analysis reduced the 27 control practices to two highly correlated factors. Tobit-regression analyses determined that vaccination practices were associated with reduced prevalence of exposure for Bovine viral-diarrhoea and EBL. Also, farms that tended to purchase their dairy animals were associated with higher seroprevalence for Johnes' disease. Neither of these two factors was associated with the seroprevalence of Neospora caninum infection. The few routine biosecurity measures that were investigated in this study were generally not related to the seroprevalences of these farms.

Direct production losses and treatment costs from bovine viral diarrhoea virus, bovine leukosis virus, Mycobacterium avium subspecies paratuberculosis, and Neospora caninum.

Our purpose was to determine direct production losses (milk loss, premature voluntary culling and reduced slaughter value, mortaliy loss, and abortion and reproductive loss) and treatmetn costs (veterinary services, medication cost, and extra farm labour cost) due to four infectious diseases in the maritime provinces of Canada: bovine viral diarrhoea (BVD), enzootic bovine leukosis (EBL), Johne's Disease (JD), and neosporosis. We used a partial-budget model, and incorporated risk and sensitivity analyses to identify the effects of uncertainty on costs. Total annual costs for an average, infected, 50 cow herd were: JD$ 2472; BVD$ 2421; neosporosis $ 2304; EBL$ 806. The stochastic nature of the proportion of infected herds and prevalence of infection within a herd were used to estimate probability distributions for these ex post costs. For all diseases, these distributions were right skewed. A sensitivity analysis showed the largest effect on costs was due to milk yield effects. For example, changing milk production loss from 0 to 5% for BVD increased the costs for the disease by 266%.