Vaccination protocols in Québec dairy herds.

Information is needed on vaccination protocols used by veterinarians and dairy producers to prevent and control infections in dairy herds. This observational study described farm's vaccination standard operating procedures (SOP) developed by veterinarians in collaboration with dairy producers in Québec. Data pertaining to vaccination protocols and dairy producer practices were collected as part of the biosecurity component of the National Mandatory Quality Assurance Certification Program (proAction). Generalized statistical mixed-effects models were used to assess associations between dairy herd characteristics and the vaccination SOP, encompassing various vaccination types. These included any vaccination, core vaccines only (bovine respiratory syncytial virus, infectious bovine rhinotracheitis herpesvirus, parainfluenza virus type 3, bovine viral diarrhea virus type 1 and type 2) and vaccination against diarrhea, mastitis, or clostridial diseases. These models accounted for random variations related to clustering by veterinarians and veterinary clinics. Furthermore, the variance of the outcome was partitioned into producer, veterinarian, and veterinary clinic levels to explore the proportion of the total variance attributable to each group. A total of 3,759 standardized vaccination procedures completed between 2018 and 2021 were analyzed. At least one vaccination target was included in the vaccination SOP in 89% of the dairy herds. The most frequently included vaccine in the SOP was core vaccines, comprising 88%, followed by mastitis (22%), neonatal diarrhea (18%), and clostridial diseases (15%). The vaccination SOPs, particularly core, mastitis, and diarrhea vaccinations, mainly varied due to the veterinarian's characteristics, followed by the clinic's characteristics. In contrast, the decision to included clostridial vaccination primarily varied with the veterinary clinic (76%). Organic producers generally included fewer vaccinations in their SOPs, including core vaccines, than conventional producers. In addition, producers who were providing access to pasture had fewer vaccination SOP for vaccination against mastitis and neonatal diarrhea but more vaccination SOP for clostridial vaccination.

Validity of luminometry and bacteriological tests for diagnosing intramammary infection at dry-off in dairy cows.

The objective of this cross-sectional study was to estimate the validity of laboratory culture, Petrifilm and Tri-Plate on-farm culture systems, and luminometry to correctly identify IMI at dry-off in dairy cows, considering all tests as imperfect. From September 2020 until December 2021, we collected composite milk samples from cows before dry-off and divided them into 4 aliquots for the luminometry test, the Petrifilm (aerobic count), the Tri-Plate, and the laboratory culture. While we assessed multiple thresholds of relative light units (RLU) for the luminometry, we used thresholds of ≥100 cfu/mL for the laboratory culture, ≥ 50 cfu/mL for the Petrifilm, and ≥1 cfu for the Tri-Plate. We fitted Bayesian latent class analysis (LCA) models to estimate the sensitivity (Se) and specificity (Sp) for each test to identify IMI, with 95% credibility interval (BCI). Using different prevalence measures (0.30, 0.50, and 0.70), we calculated the predictive values (PV) and misclassification cost terms (MCT) at different false-negative to false-positive ratios (FN:FP). A total of 333 cows were enrolled in the study from one commercial Holstein herd. The validity of the luminometry was poor for all thresholds, with Se of 0.51 (95% BCI = 0.43-0.59) and Sp of 0.38 (95% BCI = 0.26-0.50) when using a threshold of ≥150 RLU. The laboratory culture had Se of 0.93 (95% BCI = 0.85-0.98) and Sp of 0.69 (95% BCI = 0.49-0.89), the Petrifilm had Se of 0.91 (95% BCI = 0.80-0.98) and Sp of 0.71 (95% BCI = 0.51-0.90), and the Tri-Plate had Se of 0.65 (95% BCI = 0.53-0.82) and Sp of 0.85 (95% BCI = 0.66-0.97). Bacteriological tests had good PVs, with comparable positive PV for all 3 tests, but lower negative PV for the Tri-Plate compared with the laboratory culture and the Petrifilm. For a prevalence of IMI of 0.30, all 3 tests had similar MCT, but for prevalence of 0.50 and 0.70, the Tri-Plate had higher MCT in scenarios where leaving a cow with IMI untreated is considered to have greater detrimental impacts than treating a healthy cow (i.e., FN:FP of 3:1). Our results showed that the bacteriological tests have adequate validity to diagnose IMI at dry-off, but the luminometry does not. We concluded that, while luminometry is not useful to identify IMI at dry-off, the Petrifilm and Tri-Plate tests performed similarly to the laboratory culture, depending on the prevalence and the importance of the FP and FN results.

Herd-level associations between the proportion of elevated prepartum nonesterified fatty acid concentrations and postpartum diseases, reproduction, or culling on dairy farms.

The objectives of this herd-level prospective observational cohort study were to describe the proportion of cows with elevated prepartum nonesterified fatty acid concentrations (PropElevNEFA) in dairy herds and to assess the herd-level associations between PropElevNEFA and postpartum diseases, reproductive performance, and culling. From November 2018 to December 2020, a convenience sample of 49 herds was enrolled in this study. Blood sampling (16 to 29 cows per herd) was performed during the week before and during the 2 wk following calving to quantify the concentration of nonesterified fatty acids (NEFA) and ß-hydroxybutyrate acids (BHBA), respectively. Elevated NEFA was defined as ≥280 µmol/L and hyperketonemia as BHBA ≥1.4 mmol/L. Retained placenta, metritis, purulent vaginal discharge, endometritis, and mastitis were diagnosed on-farm following standardized definitions, and success at first artificial insemination (AI) and culling events were recorded. The associations between PropElevNEFA and each individual disease, success at first AI, and culling were evaluated using Bayesian aggregated binomial regression models with weakly informative priors, from the which odds ratio (OR) and the 95% credible intervals (BCI) were obtained. A total of 981 cows were included in the statistical analyses representing 16 to 29 (median = 19) cows per herd. Cows were enrolled in the prepartum period of their first to tenth (median = third) lactation, and 41% of them had an elevated prepartum NEFA concentration. At the herd level, PropElevNEFA varied between 11% and 78% (median = 39%). The odds of metritis (OR = 1.37, 95% BCI = 1.13-1.67) increased for every 10-point increase in PropElevNEFA, whereas the odds of success at first AI decreased (OR = 0.69, 95% BCI = 0.59-0.80). The PropElevNEFA was not associated with the other tested diseases or culling. Our results suggest that the herd-level proportion of cows having elevated prepartum NEFA concentrations is associated with metritis and poor success at first AI in dairy herds.

Biosecurity adoption in Québec dairy farms: results from a risk assessment questionnaire analyzed using conventional and unsupervised artificial intelligence methods.

This study documents the current state of biosecurity on dairy farms in Québec following the implementation of a mandatory biosecurity risk evaluation that was part of the proAction® accreditation program developed by Dairy Farmers of Canada. Using a cross-sectional design, 3,825 risk assessment questionnaires completed between 2018 and 2021 were extracted from Vigil-Vet database, which is a software utilized by veterinarians for conducting the proAction® risk assessment. Descriptive statistics were used to summarize the practices adopted by dairy producers. Additionally, multiple correspondence analysis was used to explore the association between the diseases of most concern and the adoption of biosecurity practices. Moreover, we used a hierarchical cluster analysis on principal components to identify distinct patterns of biosecurity practices among dairy producers. This analysis enabled the identification of typologies or clusters of farms based on the specific biosecurity practices they currently employ. The results of the descriptive statistics indicated that mastitis was the disease of most concern for most dairy farmers (40%). Moreover, given that only 10% of the 2,237 dairy farmers who acquired animals adhered to quarantine practices, there seems to be a need for improved implementation of biosecurity measures aimed at restricting the introduction of diseases when introducing new animals. Conversely, cleaning stalls and health equipment were adequately addressed by 95% and 86% of dairy producers, respectively. The multiple correspondence analysis indicated no significant association between the disease of most concern and the farm's biosecurity profile, except for respondents who identified digital dermatitis as their disease of most concern. Through the hierarchical cluster analysis, 3 clusters were identified among 3,581 farms: (1) Cluster 1 included farms with good management of sick animals; (2) Cluster 2 included farms with good management of young animals; and (3) Cluster 3 included farms with poor management of sick animals and young animals. Our study makes an important contribution by providing valuable insights into the biosecurity practices currently adopted on Québec dairy farms. It establishes a baseline for assessing progress in biosecurity practices adoption and serves as a reference point for future evaluations. In addition, these findings play a key role in monitoring the effectiveness of interventions aimed at improving biosecurity on dairy farms. By making use of this knowledge, stakeholders can make informed decisions that prioritize animal health, increase productivity, and ensure sustainability of the dairy industry.

Association between prepartum nonesterified fatty acid serum concentrations and postpartum diseases in dairy cows.

The objective of the present study was to quantify the relationships between prepartum nonesterified fatty acid (NEFA) concentrations and the development of subsequent diseases or culling and to identify the optimal thresholds allowing identification of animals at high risk of developing postpartum diseases or being culled. A total of 1,299 Holstein cows from 50 commercial herds located around Saint-Hyacinthe (QC, Canada) were enrolled in this observational study. Blood samples were collected from enrolled cows between 1 and 14 d before calving for serum NEFA quantification. Data concerning postpartum diseases and culling were collected from computerized record systems. The association between prepartum NEFA concentrations and postpartum diseases and culling was quantified using generalized linear mixed models, accounting for parity, season, week of sampling, and herd. Optimal NEFA thresholds were evaluated with receiver operator characteristic curves analysis for all diseases and then confirmed with generalized linear mixed models, considering NEFA as a categorical variable (high or low). Prepartum serum NEFA concentrations were associated with diseases diagnosed during the first 30 d in milk (DIM) and culling within the first 50 DIM. The optimal NEFA threshold associated with diseases was ≥290 µmol/L for retained placenta, ≥300 µmol/L for metritis and abomasal displacement, and ≥280 µmol/L for clinical mastitis and hyperketonemia. The level associated with the occurrence of at least one of these diseases in the first 30 DIM was ≥280 µmol/L, but it was ≥260 µmol/L for culling in the first 50 DIM. No relationship was found between NEFA concentrations and reproductive tract diseases (purulent vaginal discharge or cytological endometritis) or subclinical intramammary infection. Despite the strong relationship between prepartum NEFA concentrations and many diseases, the NEFA optimal threshold accuracy found in our study was low. In conclusion, our results demonstrate a relationship between NEFA concentrations in the 14-d period before calving and the subsequent development of diseases and culling. Prepartum NEFA concentrations thresholds between ≥260 and 300 µmol/L appear to be a strategic choice. However, considering the low accuracy, their use at the cow level should be performed with caution.

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

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

Associations of freestall design and cleanliness with cow lying behavior, hygiene, lameness, and risk of high somatic cell count.

The objective of this study was to investigate associations of freestall design and cleanliness with cow lying behavior, hygiene, lameness, and risk of new high somatic cell count (SCC). Cows from 18 commercial freestall dairy herds (22 ± 15 cows/farm; mean ± SD) in Ontario, Canada, were enrolled in a longitudinal study. Four hundred focal cows that were <120 d in milk, had no mastitis treatment in the last 3 mo, and had an SCC <100,000 cells/mL at their most recent milk test were selected for the study. Data on SCC were collected through Dairy Herd Improvement Association milk testing (at ~5-wk intervals). Each farm was visited 5 ± 3 d (mean ± SD) after each milk test until 3 tests were completed (~105 d), for a total of 3 observation periods per cow. Elevated SCC was used as an indicator of subclinical mastitis. An incident of new high SCC was defined as a cow having SCC >200,000 cells/mL at the end of an observation period, when SCC was <100,000 cells/mL at the beginning of that period. Lying behavior was recorded for 6 d after each milk sampling, using electronic data loggers. Cows were scored during each period for lameness (5-point scale, with scores ≥3 = lame), body condition score (BCS; 5-point scale; 1 = thin to 5 = fat), and hygiene (4-point scale). Stall cleanliness was assessed during each period with a 1.20 × 1.65-m metal grid, containing 88 squares. The grid was centered between stall partitions of every tenth stall on each farm, and the squares containing visible urine or fecal matter (or both) were counted. Cow lying time averaged 10.9 ± 1.9 h/d. On average, cows with low BCS (≤2.5) spent 37 ± 16.6 min/d less time lying down than high-BCS cows (≥4.0). On average, cows tended to spend 36 ± 18.3 min/d more time lying down in deep-bedded versus mattress-based stalls. Mean proportion of soiled squares per stall was 20.1 ± 0.50%. Across farms, cow lying time decreased as the proportion of soiled squares per stall increased. A difference in daily lying time of ~80 more min/d was modeled for cows housed in barns with the cleanest stalls compared with those with the dirtiest stalls. Higher neck rail height [for every 1 SD (10 cm) increase] increased the odds (odds ratio = 1.5) of cows having a dirty upper leg-flank and udder. The odds of a cow having a dirty upper leg-flank, udder, and lower legs were 1.5, 2.0, and 1.9 times greater, respectively, for cows housed with dirtier stalls. Also, cows housed on farms with dirtier stalls had 1.3 times greater odds of being lame at the time of observation. Over the study period, 50 new high-SCC cases were detected, resulting in an incidence rate of 0.45 cases of new high SCC per cow-year at risk. No measured factors were detected to be associated with risk of a new high SCC. Overall, our results confirm that cows lie down longer in cleaner and more comfortable environments. Further, these results highlight the need for improved stall cleanliness to optimize lying time and potentially reduce lameness.

Randomized controlled trial of pegbovigrastim as an adjunct therapy for naturally occurring severe clinical mastitis cases in dairy cows.

The main objective of this study was to quantify the effect of pegbovigrastim (PEG) as an adjunct therapy for naturally occurring severe mastitis cases on survival, intramammary bacteriological cure, and subsequent milk production. A double-blinded, randomized controlled trial was conducted on a single commercial dairy farm. During the study period, all cows having a case of severe clinical mastitis, defined as the presence of abnormal milk and inflammation in one quarter or more combined with the presence of systemic signs (pyrexia, dehydration, or recumbency), were enrolled in the study. In addition to a standardized therapy combining systemic and intramammary antimicrobials as well as systemic anti-inflammatory drugs, cows received a subcutaneous injection of either 2.7 mL of 0.9% sterile saline (control group; CON) or 2.7 mL of PEG (PEG group). A milk sample for bacteriological analysis was taken before treatment was administered and a second sample was taken 14 d after enrollment. Survival (30 d post-treatment) and bacteriological cure (14 d post-treatment) were analyzed by survival analysis and chi-squared tests, respectively, whereas daily milk production was treated as a repeated measure in mixed regression models. The 77 cows enrolled in the study were of parity 2 to 4 (mean = 3) and between 3 and 302 d in milk (mean = 154). The bacteria identified in milk at enrollment were Klebsiella spp. (n = 48; 62%), Escherichia coli (n = 16; 21%), Enterobacter spp. (n = 10; 13%), or no growth (n = 3; 4%). The probability of survival during the first 30 d after treatment was higher in the PEG group (84%) than in the control group (46%). Daily milk production over the 30-d period following treatment and bacteriological cure 14 d post-treatment did not differ between groups. Overall, cows treated with PEG as an adjunct therapy for naturally occurring cases of severe clinical mastitis had a better survival than cows treated with saline.

Randomized controlled trial of reinsemination strategies in dairy cows diagnosed nonpregnant using color flow Doppler ultrasonography on d 21 after insemination.

The objective of this study was to quantify the reproductive performance of 4 reinsemination strategies in cows diagnosed nonpregnant using corpus luteum color flow Doppler ultrasonography on d 21 after last insemination. A total of 2,140 color flow Doppler ultrasonography exams from 845 Holstein cows from 10 commercial dairy herds were used in this study. Farms were visited every 2 wk by the research team. On d 7 after insemination, cows were enrolled in a randomized controlled trial to be assigned 1 of 4 treatments if they were subsequently diagnosed nonpregnant on d 21. All cows were then examined on d 21 using Doppler ultrasonography to diagnose nonpregnancy. Treatment A (CON) was the control group: nonpregnant cows were programmed to receive a standard Ovsynch protocol starting on d 32. Nonpregnant cows in treatment B (GnRH) were injected i.m. with GnRH on d 21 after insemination and reinseminated immediately. Cows in treatment C (2×GnRH) received an i.m. injection of GnRH on d 11 after insemination. If diagnosed nonpregnant on d 21 after insemination, they were injected i.m. with GnRH on d 21 after insemination and inseminated immediately. Cows in treatment D (Resynch) received an i.m. injection of GnRH on d 14 after insemination. If diagnosed nonpregnant on d 21 after insemination, they were injected i.m. with PGF2α on d 21 after insemination and injected i.m. with GnRH on d 24. Then, a standard Ovsynch protocol was started on d 32. Statistical analyses were performed using mixed logistic regression models accounting for cow clustering and herd effect. A theoretical simulation was performed for each treatment to quantify the proportion of cows remaining nonpregnant 42 d after initial insemination. Of the 2,140 color flow Doppler ultrasonography exams in the study, 870 (40.6%) had a Doppler score of D0 (n = 444) or D1 (n = 426), which were indicative of nonpregnancy and used for data analysis. Overall, the number of exams assigned to each treatment was as follows: CON = 223 (25.6%), GnRH = 214 (24.6%), 2×GnRH = 220 (25.3%), and Resynch = 213 (24.5%). The final mixed multivariable logistic regression model included treatment, parity, days in milk at enrollment, and herd. Conception risk at first insemination following enrollment was 31.4, 20.6, 31.9, and 48.7% for treatments CON, GnRH, 2×GnRH, and Resynch, respectively. Based on the simulation, if 100 cows were diagnosed nonpregnant at their color flow Doppler ultrasonography exam on d 21 after last insemination, the total number of cows remaining nonpregnant 42 d after the initial insemination would be 69, 72, 58, and 51 for treatments CON, GnRH, 2×GnRH, and Resynch, respectively. Thus, the treatments used in groups 2×GnRH and Resynch for cows diagnosed nonpregnant on d 21 after insemination yielded better results than those used in the other groups.

An observational cohort study on antimicrobial usage on dairy farms in Quebec, Canada.

Quantification of antimicrobial usage (AMU) is crucial to measure the effect of intervention programs, to determine associations between usage and resistance, to compare populations, and for benchmarking purposes. The primary objective of the study was to describe quantitatively the AMU on Quebec dairy farms over 1 yr: (1) the total AMU, (2) the AMU per administration route (intramammary, injectable, oral, intrauterine), and (3) the AMU per antimicrobial class and according to the categorizations of Health Canada and the World Health Organization. The secondary objective was to assess the effect of several characteristics (herd size, level of milk production, and incidence rate of common infectious diseases) on AMU rate. The AMU data were obtained for 101 dairy farms randomly selected in 3 important Quebec dairy regions by collecting and recording all empty drug packaging and invoices for medicated feed (spring 2017 to spring 2018). The AMU rate was reported in number of Canadian defined course doses for cattle per 100 cow-years. The average herd size was 67 cows per farm, and 2/101 farms were certified organic. Overall, an estimated mean of 537 Canadian defined course doses for cattle/100 cow-years was observed. The intramammary route during lactation was the most frequently observed, followed, in decreasing order of usage, by oral route in the feed, intramammary route at drying-off, and injectable route. Oral (other than in animal feed) and intrauterine formulations were infrequently collected from the garbage cans. The 5 most frequently observed antimicrobial classes were, by decreasing order of usage, ionophores, penicillins, aminocoumarins, aminoglycosides, and polymyxins. Highest priority critically important antimicrobials as defined by the World Health Organization were mainly collected from intramammary formulations during lactation followed by injectable and drying-off intramammary formulations. The herd size was positively associated with the total AMU rate but not with the usage rate of highest priority critically important antimicrobials. Incidence of diseases along with preventive use of antimicrobials (drying-off and medicated feed with antimicrobials) explained 48% of the variance in total AMU rate.

Short communication: Accuracy of corpus luteum color flow Doppler ultrasonography to diagnose nonpregnancy in dairy cows on day 21 after insemination.

The main objective of this study was to determine the accuracy of corpus luteum color flow Doppler ultrasonography (CLCFDU) to diagnose nonpregnant dairy cows 21 d after insemination. A secondary objective was to determine the accuracy of other indirect tests such as corpus luteum size and progesteronemia. Data from 1,632 Holstein cows (10 commercial herds) were used for the analysis in this prospective cohort study. The herds were visited weekly by a veterinarian and an animal health technician. During farm visits, cows were examined on d 21 after insemination using transrectal B-mode ultrasonography to quantify the presence and size of the corpus luteum. After identification of the corpus luteum, CLCFDU was performed and scored as D0, D1, D2, or D3 when 10% or less, between 11 and 30%, between 31 and 60%, or 61% or more of the corpus luteum surface was colored, respectively. A blood sample from coccygeal vessels was also collected to quantify progesteronemia. Farmers were blinded to these findings and no intervention was performed following examination. On d 32 after insemination, the cows were examined by the regular herd veterinarian using transrectal palpation and B-mode ultrasonography to determine whether the cows were pregnant or not (the reference test). Statistical analyses were conducted using 2 × 2 contingency tables. The apparent prevalence, sensitivity, specificity, positive predictive value, and negative predictive value of CLCFDU for predicting nonpregnancy were 22.0, 36.6, 99.0, 98.1, and 52.0%, respectively, when using D0 only as the diagnostic criterion; they were 47.2, 76.4, 94.8, 93.5, and 73.8%, respectively, for D0+D1 criteria. The same measures for cows with a corpus luteum <15 mm were 8.0, 11.7, 97.5, 86.9, and 43.4%, respectively, and they were 51.9, 67.4, 70.4, 76.6, and 60.0%, respectively, for progesteronemia <1 ng/mL. The measures of accuracy of CLCFDU to identify nonpregnant cows on d 21 after insemination were high, and the apparent prevalence varied depending on the diagnostic criteria used. The measures of accuracy of corpus luteum size (<15 mm) for the same purpose were high; however, apparent prevalence was low. The measures of accuracy of progesteronemia (<1 ng/mL) were low. In conclusion, CLCFDU had excellent accuracy to diagnose nonpregnancy in dairy cows on d 21 after insemination.

Bacterial concentrations in bedding and their association with dairy cow hygiene and milk quality.

Comparison of bacterial counts (BCs) among common bedding types used for dairy cows, including straw, is needed. There is concern that the microbial content of organic bedding is elevated and presents risks for dairy cow udder health and milk quality. The objectives of this study were to investigate: (1) % DM and BCs (Streptococcus spp., all gram-negatives and specifically Klebsiella spp.) in different types of bedding sampled, and to investigate housing and farm management factors associated with % DM and BCs; (2) if bedding type was associated with hygiene of cow body parts (lower-legs, udder, upper-legs and flank) and housing and management factors associated with hygiene and (3) bedding types associated with higher BCs in cow milk at the farm level and bulk tank milk and management factors that were associated with highest BCs. Seventy farms (44 free-stall and 26 tie-stall) in Ontario, Canada were visited 3 times, 7 days apart from October 2014 to February 2015. At each visit, composite samples of unused and used bedding were collected for % DM determination and bacterial culture. Used bedding samples were collected from the back third of selected stalls. Data were analyzed using multivariable linear mixed models. Bedding classification for each farm were: new sand (n = 12), straw and other dry forage (n = 33), wood products (shavings, sawdust; n = 17) and recycled manure solids (RMSs)-compost, digestate (n = 8). In used bedding, across all bedding samples, sand was driest, compared to straw and wood, and RMS; higher % DM was associated with lower Streptococcus spp. count. Streptococcus spp. and all Gram-negative bacteria counts increased with increasing days since additional bedding was added. Gram-negative bacteria counts in used bedding varied with type: RMS = 16.3 ln colony-forming units (cfu)/mL, straw = 13.8 ln cfu/mL, new sand = 13.5 ln cfu/mL, and wood = 10.3 ln cfu/mL. Klebsiella spp. counts in used bedding were lower for wood products (5.9 ln cfu/mL) compared to all other bedding types. Mean cow SCC tended to be higher on farms with narrower stalls. Farms with mattress-based stalls had a higher prevalence of cows with dirty udders compared to those using a deep bedding system (often inorganic sand). Wider stalls were associated with lower bulk milk bacteria count. Lower % DM of used bedding was associated with higher bulk milk bacteria count. In conclusion, bedding management may have a profound impact on milk quality, bacterial concentrations in the bedding substrates, and cow hygiene.

Measuring Population Health from a Broader Perspective: Assessing the My Quality of Life Questionnaire.

INTRODUCTION: Population health perspectives increasingly focus on people's perception of resilience, ability to adapt and self-manage. The goal of this study is to determine whether the MijnKwaliteitVanLeven.nl ("MyQualityOfLife.nl") survey is a valid and reliable instrument for assessing the broader health perspectives at population level. METHODS: 19,809 entries of the MyQualityOfLife.nl survey were used. To assess face validity, Huber's six dimensions of positive health were used as a framework for expert feedback. A confirmative factor analyses was done using the expert's item clustering, followed by data-driven explorative factor analyses and reliability tests. RESULTS: Experts distributed 74 of the 118 items over all six dimensions of positive health. The confirmatory factor analysis model based on expert classification was not confirmed. The subsequent exploratory factor analysis excluded most items based on factor loading and suggested two factors; 'quality of life' and 'daily functioning', both showing excellent reliability. CONCLUSION: The MyQualityOfLife.nl survey can assess the broader concept of health in a population as well as 'quality of life' and 'daily functioning'. However, the survey can currently not evaluate several of the positive health dimensions separately. Further research is needed to determine whether this is due to the instrument or the positive health dimensions.

Partial prediction of the duration and the clinical status of Staphylococcus aureus bovine intramammary infections based on the phenotypic and genotypic analysis of isolates.

Staphylococcus aureus is a bacterial pathogen causing bovine intramammary infections (IMIs) often leading to chronic clinical or subclinical mastitis. Predicting the outcome of S. aureus IMIs (duration and clinical vs subclinical) based on the characterization of isolates would help to make better case management decisions. For this purpose, 583 S. aureus isolates from series of quarter milk samples were characterized by genotypic tests (detection of virulence genes seg, tst, lukM), epidemiological typing (spa type) and by a phenotypic test (biofilm production). VNTR typing (variable number of tandem repeats) was used to establish persistence of the same S. aureus strain in each series of sequential isolates. This allowed to associate each strain to a clinical/subclinical status and to validate the duration of infection. We found differences in the distribution of spa types between the strains from clinical and subclinical cases. Prevalence of lukM was also higher in strains from clinical cases than in strains from subclinical cases. A Kaplan-Meier analysis was then used to determine factors influencing the duration of the infection. Considering a multivariable model of the logistic regression, time to elimination was shorter with the strains of the subclinical lactation series compared to the clinical series (series with at least one clinical case). Strains from the spa type t359 and t529 were less likely to persist compared to those of spa type t13410. In sum, strain characterization including determination of the spa type helps to predict duration of infection and the clinical or subclinical outcome of S. aureus IMIs.

Harvesting the wisdom of the crowd: using online ratings to explore care experiences in regions.

BACKGROUND: Regional population health management (PHM) initiatives need an understanding of regional patient experiences to improve their services. Websites that gather patient ratings have become common and could be a helpful tool in this effort. Therefore, this study explores whether unsolicited online ratings can provide insight into (differences in) patient's experiences at a (regional) population level. METHODS: Unsolicited online ratings from the Dutch website Zorgkaart Nederland (year = 2008-2017) were used. Patients rated their care providers on six dimensions from 1 to 10 and these ratings were geographically aggregated based on nine PHM regions. Distributions were explored between regions. Multilevel analyses per provider category, which produced Intraclass Correlation Coefficients (ICC), were performed to determine clustering of ratings of providers located within regions. If ratings were clustered, then this would indicate that differences found between regions could be attributed to regional characteristics (e.g. demographics or regional policy). RESULTS: In the nine regions, 70,889 ratings covering 4100 care providers were available. Overall, average regional scores (range = 8.3-8.6) showed significant albeit small differences. Multilevel analyses indicated little clustering between unsolicited provider ratings within regions, as the regional level ICCs were low (ICC pioneer site < 0.01). At the provider level, all ICCs were above 0.11, which showed that ratings were clustered. CONCLUSIONS: Unsolicited online provider-based ratings are able to discern (small) differences between regions, similar to solicited data. However, these differences could not be attributed to the regional level, making unsolicited ratings not useful for overall regional policy evaluations. At the provider level, ratings can be used by regions to identify under-performing providers within their regions.

A randomized controlled trial on the effect of incomplete milking during the first 5 days in milk on reproductive performance of dairy cows.

The main objective of the current study was to measure the effect of incomplete milking on luteal activity and on pregnancy hazard. We also aimed to study the effect of early-lactation hyperketonemia (i.e., ß-hydroxybutyrate blood concentration ≥1.4 mmol/L during the first 3 wk in milk) on those reproductive outcomes. Multiparous Holstein cows (n = 853) from 13 commercial herds were enrolled in a randomized controlled trial. Cows were assigned to a control or a treatment group, incompletely milked (10-14 L of milk collected/d) from 1 to 5 DIM. Blood samples were collected once a week during weeks in milk 1 to 3 for ß-hydroxybutyrate blood concentration, and a threshold of 1.4 mmol/L was used to define hyperketonemia. During weeks in milk 5 and 7, cows were sampled for progesterone blood concentration, and a threshold of 1 ng/mL was used to define luteal activity. Reproductive information and culling dates were obtained through herd records. Logistic regression models and survival analyses were used to assess the effect of treatment on luteal activity and on pregnancy hazard, respectively. Analogous models were used to investigate the effect of early-lactation hyperketonemia on reproductive outcomes. The odds of luteal activity for incompletely milked cows were 1.1 (95% confidence interval: 0.72-1.7) times those of conventionally milked cows. The effect of treatment on pregnancy hazard varied as a function of time, parity, and start of the breeding period. In second-parity cows that started the breeding period <55 d in milk, the pregnancy hazard (95% confidence interval) in incompletely milked cows was 576.3 (240.0-1,383.7), 36.9 (18.9-72.1), 6.8 (3.3-13.8), 2.5 (1.0-5.9), and 0.13 (0.07-0.26) times that of conventionally milked cows at 1 to 21, 22 to 43, 44 to 65, 66 to 87, and >87 d after the voluntary waiting period, respectively. The treatment did not have an effect on pregnancy hazard in cows in third parity or greater or in those starting the breeding period ≥55 d in milk. Early-lactation hyperketonemia was not associated with any of the reproductive outcomes. In conclusion, the incomplete milking protocol had no effect on luteal activity and had a positive effect on pregnancy hazard in second-parity cows in herds with a short voluntary waiting period (<55 d). We did not observe an effect of early-lactation hyperketonemia on luteal activity or on pregnancy hazard.

Effect of incomplete milking during the first 5 days in milk on udder and reproductive tract health: Results from a randomized controlled trial.

The aim of this study was to investigate the effect of an incomplete milking on risk of mastitis and reproductive tract disease. Multiparous dairy cows (n = 878) from 13 commercial herds were enrolled in a randomized controlled trial. Cows were randomly assigned to either a control (milked conventionally) or a treatment group, which consisted of an incomplete milking (10-14 L of milk collected/d) from 1 to 5 d in milk (DIM). Quarter milk samples were collected at approximately 11 and 18 DIM to measure somatic cell count (SCC). Quarters were considered negative for intramammary infection if SCC was <100,000 cells/mL and positive if SCC was ≥200,000 cells/mL. To calculate intramammary infection incidence, negative quarters of the initial samples collected were tested again 1 wk later. This was done to deter incidence of positive quarters. To calculate elimination rate, positive quarters were tested again 1 wk later to detect mastitis elimination. Farmers recorded clinical mastitis events. Cows were also examined at approximately 35 DIM with a Metricheck device (Simcro, Hamilton, New Zealand) for detection of purulent vaginal discharge (PVD) and with an endometrial cytobrush for presence of leukocytes [endometrial cytology for smear (ENDO) and for leukocyte esterase test (LE)]. A threshold ≥3 was used to define a positive PVD or LE test, whereas a polymorphonuclear cell count ≥6% was used to define a positive ENDO. Five generalized mixed models with cow or herd as random intercepts were used to determine the effects of incomplete milking on odds of new intramammary infection, odds of intramammary infection elimination, and odds of a positive PVD, LE, or ENDO status. To investigate time until first clinical mastitis event, a Cox model with a herd frailty term was used. The odds of new intramammary infection and intramammary infection elimination for incompletely milked cows were 0.90 [95% confidence interval (CI): 0.49, 1.7] and 2.9 (95% CI: 1.4, 6.0) times those of conventionally milked cows, respectively. The hazard of clinical mastitis in incompletely milked cows was 0.96 (95% CI: 0.59, 1.6) times that of conventionally milked cows. The odds of PVD, LE, and ENDO for incompletely milked cows were 1.4 (95% CI: 0.89, 2.1), 1.3 (95% CI: 0.88, 1.8), and 1.2 (95% CI: 0.81, 1.7) times those of conventionally milked cows. These results suggest that incomplete milking during the first 5 DIM increases the odds of a decrease in SCC from 11 to 18 DIM but does not affect odds of increase in SCC in the same period. The incomplete milking had no effect on clinical mastitis incidence in the first 90 DIM or on reproductive tract health at 35 DIM.

A randomized controlled trial on the effect of incomplete milking during early lactation on ketonemia and body condition loss in Holstein dairy cows.

Limiting milk production for a short period of time in early lactation could be a relevant strategy to prevent hyperketonemia (HYK). From December 2013 to March 2015, 838 multiparous Holstein cows from 13 herds were enrolled in a randomized controlled trial evaluating the effect of incomplete milking in early lactation on ketonemia and its effect on body condition score (BCS) loss. Cows were randomly assigned 4 wk before expected calving date to 1 of 2 treatment groups, (1) a conventional milking protocol (CON) for which cows were completely milked or (2) an incomplete milking protocol (INC) for which a maximum of 10 to 14 kg of milk/d were withdrawn during the first 5 d in milk (DIM). ß-Hydroxybutyrate (BHB) concentrations were measured from blood samples collected on each cow 3 times at weekly intervals. Hyperketonemia was defined as BHB ≥1.4 mmol/L. Body condition score variation in the postcalving period was calculated by subtracting BCS assessed at wk 7 from BCS assessed at first week after calving. Effect of treatment on ketonemia and prevalence of HYK were evaluated for 4 specific time periods: 1 to 3, 4 to 7, 8 to 17, and 18 to 26 DIM. Effect of treatment on ketonemia was investigated using linear mixed models with natural logarithm of BHB measurements as outcome and treatment groups as fixed effect. Generalized linear mixed models with HYK as outcome, using logit link, and treatment groups as fixed effect were used to investigate effect of treatment on odds of HYK. A logistic regression model with BCS loss (<0.75 or ≥0.75) as outcome and treatment groups and herd as fixed effects was used to study effect of INC on odds of having BCS loss ≥0.75. A total of 813 lactations had complete data and were used for statistical analysis of ketonemia and HYK. A total of 709 lactations had complete data and were used for analysis of BCS loss. Geometric means of blood BHB concentrations during the 1 to 3, 4 to 7, 8 to 17, and 18 to 26 DIM periods were, respectively, 0.72 (95% confidence interval = 0.66, 0.80), 0.66 (0.60, 0.73), 0.90 (0.80, 1.01), and 0.93 (0.83, 1.05) mmol/L for INC, and 0.65 (0.59, 0.72), 0.79 (0.72, 0.87), 0.94 (0.84, 1.06), and 0.92 (0.82, 1.04) mmol/L for CON. Cows in INC group had lower ketonemia during the 4 to 7 DIM period. Predicted prevalence of HYK during the 1 to 3, 4 to 7, 8 to 17, and 18 to 26 DIM periods were, respectively, 2.8 (3.2, 15.1), 4.6 (2.0, 10.0), 13.4 (8.4, 20.0), and 23.0% (17.4, 29.7) for INC and 2.6 (2.5, 13.8), 10.7 (5.6, 19.3), 19.4 (13.0, 27.9), and 21.3% (16.0, 27.8) for CON. The INC treatment reduced the prevalence of HYK during the 4 to 7 and 8 to 17 DIM periods. No association was observed between INC and BCS loss in the postcalving period. Overall, the incomplete milking protocol was effective for reducing ketonemia and prevalence of HYK during the early postpartum period.

A randomized controlled trial on the effect of incomplete milking during the first 5 days in milk on culling hazard and on milk production and composition of dairy cows.

An incomplete milking in early lactation could help limit negative energy balance in dairy cattle, but its potential effects on culling hazard and on milk production and composition throughout the entire lactation are unknown. The objective of this study was to evaluate the effect of an incomplete milking during the first 5 d in milk on culling hazard, milk weight, milk fat and protein concentrations, and energy-corrected milk (ECM) yield during the whole lactation. A randomized controlled trial was conducted in 13 dairy farms near St-Hyacinthe, Quebec, Canada. Approximately 1 mo before expected calving, Holstein multiparous cows calving between December 2013 and March 2015 (n = 846 cow lactations) were randomly assigned to a control or a treatment group. Cows in the control group were milked conventionally, whereas cows in the treatment group were submitted to an incomplete milking protocol (maximum of 10, 12, and 14 L/d of milk was collected on days in milk 1-3, 4, and 5, respectively). All farms were registered on Dairy Herd Improvement Association, which was used to obtain records on culling, monthly milk yield, and milk fat and protein concentrations. In addition, daily milk yield records were available for 6 farms. A Cox proportional hazards model with a herd frailty term was fitted to the data to compare culling hazard among treatment groups. Regarding milk production and composition, 4 linear mixed models with herd as a fixed effect, cow as a random effect, and using an autoregressive covariance structure were used to study the effect of the incomplete milking on (1) milk weight, (2) milk fat concentration, (3) milk protein concentration, and (4) ECM yield. Culling hazard did not differ among treatment groups (hazard ratio = 1.0; 95% CI = 0.82, 1.3). We observed no differences in milk weight, milk fat, or protein concentration among treatment groups between weeks in milk (WIM) 2 and 44 (the studied period). We noted a difference in ECM between treatment groups for WIM 38, with incompletely milked cows producing less milk than conventionally milked cows (-2.7 kg/d; 95% CI = -0.02, -5.2 kg/d), but no differences were found for any of the other WIM. These results suggest that this strategy for controlling the negative energy balance has negligible effect on cow productivity.

Prognostic Value of Cardiac Troponin I and L-Lactate in Blood of Dairy Cows Affected by Downer Cow Syndrome.

BACKGROUND: The downer cow syndrome (DCS) is a challenging health issue in the dairy industry. No cow-side test is available to provide an accurate prognosis for DCS cases in farm settings. HYPOTHESIS/OBJECTIVES: Local or systemic hypoperfusion and myocardial lesions lead to an increase in blood concentration of biomarkers cardiac troponin I (cTnI) and L-lactate. The objective was to determine the prognostic values of these biomarkers assessed cow-sides in addition to clinical examinations in prognostication of a negative outcome (NO: death or euthanasia within 7 days). ANIMALS: 218 client-owned dairy cows affected by DCS. METHODS: In a prospective study, animals were monitored for 60 days after inclusion of each cow. Blood cTnI and L-lactate concentrations were measured on the day of inclusion. The prognostic accuracy of both biomarkers and physical examination variables was estimated to predict NO. A mixed multivariable logistic regression model was used for data analysis. RESULTS: Prevalence of NO in this study was 63% on day 7. Troponin concentrations greater than 0.7 ng/mL had sensitivity and specificity of 54.1% (95% CI: 45.3-62.7%) and 78.4% (95% CI: 67.3-87.1%), respectively, for predicting NO. Blood L-lactate was not associated with the outcome. The multivariable model revealed that heart rate >100 bpm (OR; 95% CI: 3.7; 1.3-10.2) and cTnI > 0.7 ng/mL (OR; 95% CI: 5.5; 2.1-14.6) were associated with the risk of NO. CONCLUSIONS AND CLINICAL IMPORTANCE: Hypertroponinemia and tachycardia were associated with reduced survival in DCS cases. The use of cow-side blood cTnI concentrations and heart rate could help to rapidly identify cows in farm setting that have poor chances of recovery and would benefit from a more aggressive treatment or euthanasia.