Characterizing the attitudes and motivations of Ontario dairy producers toward udder health.

Considerable research has focused on identifying risk factors for intramammary infections, yet mastitis remains a pervasive disease on dairy farms. Increasingly, researchers are appreciating the role of dairy producer mindset in determining management style and thus udder health status of the herd. The objective of this study was to explore the attitudes and motivations of Ontario dairy farmers toward udder health in herds with varying bulk milk somatic cell count (BMSCC). In December 2011, 5 focus groups were conducted across Ontario, Canada, with independent groups of dairy producers representing low, medium, and high BMSCC herds. Groups were established based on producer's weighted BMSCC levels as recorded over the summer of 2011. A semi-structured interview guide was followed to discuss topics relating to udder health. Thematic analysis was performed on the interview transcripts. Generally, producers noted management techniques (specifically culling infected cows and monitoring BMSCC), a perceived wealth of information on mastitis control, and a proactive whole-herd management approach engender the perception of control over mastitis. Producers in the low BMSCC group were confident in their level of knowledge and control of mastitis in their herds, whereas high BMSCC producers generally felt lower levels of control. Several areas were identified by producers that counteract this perception, contributing to perceived low levels of control over mastitis. Participants identified that at certain times they do not understand the cause of BMSCC on their farm. This attitude was especially prominent in the high BMSCC group. Other times, producers cited improper sample handling, seasonal issues, perceived milk culture shortcomings, and low herd size as factors that limited their control over mastitis in their herds. Though producers generally have high levels of self-efficacy beliefs when it comes to udder health management, the perception still exists that, under certain situations, mastitis is uncontrollable. This highlights the fact that educational and extension efforts need to focus on ensuring that producers employ proven mastitis diagnostic, prevention, and treatment practices in a systematic manner, with realistic expectations.

Short communication: Describing mortality and euthanasia practices on Canadian dairy farms.

The objective of this study was to describe mortality rates and euthanasia practices used for cows, heifer calves, and male dairy calves on Canadian dairy farms. An internet survey was administered to Canadian dairy producers between March and April 2015 to collect information on current management practices. Approximately 81% (867/1,076) and 63% (673/1,065) of respondents reported that at least one animal died unassisted and at least one animal was euthanized on the farm in the preceding 12-mo period, respectively. Overall, mean mortality was 8% for cows, and 6 and 2% for preweaning and weaned heifers, respectively. On average, 48, 76, and 89% of all reported mortality events in cows, weaned heifers, and preweaning heifers were recorded as unassisted deaths. Cows that died without assistance were necropsied more often than preweaning heifers dying without assistance; these cows were also necropsied more than cows that were euthanized. Conversely, preweaning heifers that were euthanized were necropsied more frequently than those that died without assistance. Choosing not to perform necropsies on animals that die of unknown causes could represent a missed opportunity to identify cause of death and inform changes to prevent future deaths. The use of a firearm was the most common method for euthanizing cows and heifers (54%) and male dairy calves (51%). Approximately 7% of respondents reported using blunt force to euthanize animals. The use of this method was much higher for euthanasia of male dairy calves (34%) than for heifer calves (7%). Québec respondents euthanized their animals using blunt force more often than farmers from other regions. Further, 53% of respondents using blunt force indicated it was their primary method of calf euthanasia; these results are extremely concerning. Approximately 31% of respondents who reported that they do not use blunt force to euthanize heifers and cows did report using blunt force to euthanize male dairy calves. These results can be used to inform veterinarian-client communication, broader extension tools and programs, and industry policies to improve dairy cattle health and welfare, a goal that is becoming of increasing importance from a consumer assurance perspective.

Canadian National Dairy Study: Describing Canadian dairy producer practices and perceptions surrounding cull cow management.

Farmer decisions surrounding culling have an important effect on the health and welfare of cull cows. The objectives of this study were to describe the self-reported shipment behaviors of Canadian dairy producers and understand farmer perspectives on the factors that were most influential in their decision to cull a cow. A nationwide survey was administered between March and April 2015 that included 192 questions covering producer background information, farm characteristics, biosecurity practices, disease prevalence, calf health, cow welfare, lameness, milking hygiene, reproduction, and Internet and social media use. The survey yielded a 12% response rate; a total of 1,076 respondents (78% of all survey respondents completed the culling section of the survey) were included in this study for analysis. Approximately 80, 51, and 38% of respondents reported shipping at least 1 cow to auction, direct to slaughter, and to another dairy farm in the past 12 mo, respectively. Ability of the cow to remain standing (93% of respondents) and drug withdrawal times (92% of respondents) were identified as the most important factors for consideration when culling cows. The time between culling decision and when the cow was actually transported was longer for lame cows than sick cows; almost 70% of respondents reported that cows culled for illness were typically shipped within 1 wk of culling decision, whereas only 51% of respondents indicated the same was true for lame cows. Last, Canadian dairy producers generally exhibited strong confidence that their culled cows would arrive at slaughter in the same condition as they left, but felt very unsure about knowing the location of their final destination. These results highlight several gaps between producer perceptions and the true situation, and can be used to develop tailored programs and inform policy and regulatory decisions aimed at improving cull cow decisions and cow welfare.

Cost-benefit of implementing a participatory extension model for improving on-farm adoption of Johne's disease control recommendations.

The objective of this study was to perform a cost-benefit analysis (CBA) of a participatory extension model, called Ontario Focus Farms (FF), which was designed to facilitate the adoption of on-farm management practices to control Johne's disease (JD) on Ontario (ON) dairy farms. Partial budget models were developed to estimate the annual herd cost of JD on an average 78-cow Ontario dairy herd and the annual herd cost of neonatal calf diarrhea (NCD). With these estimates, a CBA was developed to assess the simulated net benefits of implementing various on-farm management scenarios (i.e., implementing 1, 2, or 3 of the following: calf feeding, maternity pen management, maternity area structure changes), where the benefits represent a reduction in the annual cost of JD and NCD. These models informed the final CBA assessing the net benefits of FF implementation over a 10-yr period. All monetary values are reported in Canadian dollars (Can$; where 1 Can$ = 0.823 US$ at the time of the study). The annual herd cost of JD was estimated to be $3,242 ($41.56/cow), and that of NCD was estimated to be $1,390 ($36/heifer calf). When farms were expected to have both JD and NCD, all scenarios, when implemented over a 10-yr period, yielded positive net benefits ranging from $439 to $2,543 per farm when changes to maternity area structure were combined with calf feeding changes. These effects were sensitive to changes in level of disease (JD and NCD) on the farm, and the costs and effects of making changes. The NPV of making any on-farm change when JD was not present on the farm was negative. Overall, FF implementation yielded positive net benefits of $426,351 or $749,808, depending on whether a veterinarian or non-veterinarian served as the facilitator. The NPV was most sensitive to changes in burden of disease, the cost of implementing changes, and the proportion of FF participants that had JD and NCD on the farm. Benefits of FF implementation are also likely to accrue to veterinarians, as a result of professional facilitator training, and the Ontario dairy industry, as a by-product of improved milk quality and safety; therefore, the true net benefits of FF implementation are likely underestimated. Overall, the FF process should be considered an economically viable program and worthy of investment as part of a JD control strategy, as it demonstrates potential to yield positive net benefits for the Ontario dairy industry.

Adoption and consistency of application of premilking preparation in Ontario dairy herds.

Milking management practices that affect udder health have been widely studied, leading to a variety of evidence-based recommendations. Lack of adoption or inconsistency in milking practices can interfere with efforts to prevent mastitis in the herd. The study objective was to assess the variation in adoption and application consistency of important milk harvest practices between and within farms over time. During the summer of 2013, 50 herds in southern Ontario were visited twice within a month, at milking time, and a single person observed and time-recorded premilking preparation procedures. A generalized mixed model was used to partition the variance for predisinfectant contact time and preparation lag time (time between the first contact with the teats and cluster attachment), and determine the proportion of variation attributable to farms, milkers, visits, and characteristics of a cow milking. Using logistic regression, models were built to assess factors affecting adequate contact time and adequate preparation lag time, respectively. Farm, the person(s) milking, and visit number were used as random effects in both instances. In both models, farm-to-farm differences and variations between cows during a specific milking accounted for the largest part of the variability seen in both contact time (47 and 44%, respectively) and preparation lag time (40 and 36%, respectively). For both outcomes, milkers were consistent in their routines over the 2 visits (only 9 and 3.1% of total variance for contact and preparation lag time, respectively). Parlors were more likely to meet the recommended contact time than tie-stalls; increased number of milkers at milking time and having contact times under 30 s had negative effects on meeting recommended preparation lag time. The majority of farms in the study complied with the recommendations for adequate milking practices; however, most did not follow a consistent timed protocol. There are several potential sources of variation in the milking routine on a dairy farm. To improve milk quality and udder health, it is important to identify whether best management practices are being implemented on each farm. Producers appeared to be consistent in the application of milking procedures across time, regardless of whether or not they were correct. Hence, with corrective education and training, improvements in these practices could be experienced and maintained to promote better udder health.

Studying the relationship between on-farm environmental conditions and local meteorological station data during the summer.

High ambient heat and humidity have profound effects on the production, health, profitability, and welfare of dairy cattle. To describe the relationship between summer temperature and relative humidity in the barn and determine the appropriateness of using meteorological station data as a surrogate for on-farm environmental monitoring, a study was conducted on 48 farms in Ontario, Canada, over the summer (May through September) of 2013. Within-barn environmental conditions were recorded using remote data loggers. These values were compared with those of the closest official meteorological station. In addition, farm-level characteristics and heat-abatement strategies were recorded for each farm. Environmental readings within the barn were significantly higher than those of the closest meteorological station; however, this relationship varied greatly by herd. Daily temperature-humidity index (THI) values within the barn tended to be 1 unit higher than those of the closest meteorological station. Numerically, 1.5 times more mean daily THI readings were in excess of 68 (heat stress threshold for lactating dairy cows) in the barn, relative to the closest meteorological station. In addition, tiestalls, herds that were allowed access to pasture, and herds that had no permanent cooling strategy for their cows had the highest mean and maximum daily THI values. Minimum daily THI values were almost 4 units higher for tiestall relative to freestall herds. Overall, due to farm-specific and unpredictable variability in magnitude of environmental differences between on-farm and meteorological station readings, researchers attempting to study the effects of environment on dairy cows should not use readings from meteorological stations because these will often underestimate the level of heat stress to which cows are exposed.

Exploring the characteristics and dynamics of Ontario dairy herds experiencing increases in bulk milk somatic cell count during the summer.

Regionally aggregated bulk milk somatic cell count (BMSCC) data from around the world shows a repeatable cyclicity, with the highest levels experienced during warm, humid seasons. No studies have evaluated this seasonal phenomenon at the herd level. The objectives of this study were to define summer seasonality in BMSCC on an individual herd basis, and subsequently to describe the characteristics and dynamics of herds with increased BMSCC in the summer. The data used for this analysis were from all dairy farms in Ontario, Canada, between January 2000 and December 2011 (n≈4,000 to 6,000 herds/yr). Bulk milk data were obtained from the milk marketing board and consisted of bulk milk production, components (fat, protein, lactose, other solids), and quality (BMSCC, bacterial count, inhibitor presence, freezing point), total milk quota of the farm, and milk quota and incentive fill percentage. A time-series linear mixed model, with random slopes and intercepts, was constructed using sine and cosine terms as predictors to describe seasonality, with herd as a random effect. For each herd, seasonality was described with reference to 1 cosine function of variable amplitude and phase shift. The predicted months of maximal and minimal BMSCC were then calculated. Herds were assigned as low, medium, and high summer increase (LSI, MSI, and HSI, respectively) based on percentiles of amplitude in BMSCC change for each of the 4 seasons. Using these seasonality classifications, 2 transitional repeated measures logistic regression models were built to assess the characteristics of MSI and HSI herds, using LSI herds as controls. Based on the analyses performed, a history of summer BMSCC increases increased the odds of experiencing a subsequent increase. As herd size decreased, the odds of experiencing HSI to MSI in BMSCC increased. Herds with more variability in daily BMSCC were at higher odds of experiencing MSI and HSI in BMSCC, as were herds with lower annual mean BMSCC. Finally, a negative association was noted between filling herd production targets and experiencing MSI to HSI in BMSCC. These findings provide farm advisors direction for predicting herds likely to experience increases in SCC over the summer, allowing them to proactively focus udder health prevention strategies before the high-risk summer period.