The prevention and control of endemic pathogens within and between farms often depends on the adoption of best management practices. However, farmers regularly do not adopt recommended measures or do not enroll in voluntary disease control programs. This indicates that a more comprehensive understanding of the influences and extension tools that affect farmers' management decisions is necessary. Based on a review of relevant published literature, we developed recommendations to support policy-makers, industry representatives, researchers, veterinarians, and other stakeholders when motivating farmers to adopt best management practices, and to facilitate the development and implementation of voluntary prevention and control programs for livestock diseases. Farmers will make management decisions based on their unique circumstances, agricultural contexts, beliefs, and goals. Providing them with rational but universal arguments might not always be sufficient to motivate on-farm change. Implementation of recommended management practices is more likely if farmers acknowledge the existence of a problem and their responsibility to take action. The perceived feasibility and effectiveness of the recommended management strategy and sufficient technical knowledge further increase the likelihood of adequate adoption. Farmers will also weigh the expected advantages of a proposed change against the expected disadvantages, and these considerations often include internal drivers such as pride or the desire to conform with perceived standards. Extension tools and farmers' social referents (e.g., veterinarians, peers) not only provide technical information but also influence these standards. Whereas mass media have the potential to deliver information to a broad audience, more personal approaches such as participatory group learning or individual communication with farm advisors can enable the tailoring of recommendations to farmers' situations. Approaches that appeal to farmers' internal motivators or that unconsciously elicit the desired behavior will increase the success of the intervention. Collaboration among stakeholders, assisted by social scientists and communication specialists, is necessary to provide a context that facilitates on-farm change and transfers consistent messages across extension tools in the most effective way.

Lameness is a severe welfare problem and a production-limiting disease in dairy farming. The objectives of this study were to determine prevalence of lameness and investigate cow- and herd-level factors associated with lameness in dairy cows housed in freestall barns in 3 Canadian provinces. A purposive sample of 40 Holstein-Friesian cows was selected from each of 141 dairy farms in Québec, Ontario, and Alberta. In total, 5,637 cows were scored once for lameness (presence of limping when walking). Data collected included information on individual cows (hock lesions, claw length, body condition score, parity, days in milk, and milk production), management practices (floor and stall cleaning routine, bedding routine, and footbath practices), and facility design (stall dimensions, stall base and bedding type, width of feed alley, flooring type, and slipperiness) hypothesized to be risk factors for lameness. Multilevel mixed logistic regression models were constructed (including farm as a random effect and province as a fixed effect). Herd-level lameness prevalence ranged from 0 to 69% (mean = 21%). Lameness prevalence increased with increasing parity; compared with first parity, cows in parity 2, 3, and ≥ 4 had 1.6, 3.3, and 4 times, respectively, higher odds of being lame. Furthermore, the odds of lameness were 1.6 times greater in cows with low body condition score (≤ 2.5) than in cows with a higher body condition score. In addition, injured hocks and overgrown claws were associated with 1.4- and 1.7-fold increased odds of being lame, respectively, whereas every 1 kg increase in daily milk production was associated with a 3% decrease in the odds of being lame. Lameness prevalence was higher in herds with ≤ 100 cows, but lower in barns with a sand or dirt stall base, or with bedding ≥ 2 cm deep. Cows exposed to very slippery floors had 2 times the odds of being lame compared with cows exposed to nonslippery floors. We attributed the wide range of lameness prevalence to the great variability in facilities and management practices among farms. Finally, we inferred that the prevalence of lameness could be decreased by improving management of multiparous, thin, or injured cows and by adopting management practices intended to improve cow comfort, namely the floor's slip resistance and the stall's lying surface.

The objectives of this cross-sectional study were to determine the prevalence and distribution of foot lesions and associated cow- and herd-level risk factors in dairy cows in Alberta, Canada. Foot lesion data were recorded electronically by 7 hoof trimmers on 28,607 cows in 156 dairy farms from June 2009 to November 2012. Foot lesion prevalence estimates differed between farms that had the whole herd trimmed at once (≥80% of lactating cows were trimmed; n=69 farms and 8,020 cows) and farms on which part of the herd was trimmed (selection of cows was determined by farmer and <80% of lactating cows were trimmed; n=87 and 20,587 cows). Estimates were consistently higher for the latter likely because farmers presumably prioritized lame cows in partial-herd trims. On farms with whole-herd trims, digital dermatitis was the most common lesion among all housing types, present in 15% of cows and 94% of herds. Sole ulcers and white line disease were detected in 6 and 4% of the cows and 92 and 93% of herds, respectively. Other infectious and claw horn lesions each affected 1 to 2% of cows and 62 to 78% of herds. Intraclass correlation coefficients for hoof trimmers ranged from 0.01 to 0.20 for all lesions, indicating some clustering of recorded lesions by trimmer. Multilevel mixed logistic regression models were constructed (including hoof trimmer as fixed and farm as random effects) for the 3 most frequently identified lesions. Prevalence of digital dermatitis decreased with increasing parity, but this effect interacted with days in milk (DIM); primiparous cows had higher odds of digital dermatitis in mid lactation (100-199 DIM) and late lactation (≥200 DIM) compared with cows at other stages of lactation. In contrast, prevalence of sole ulcers and white line disease increased with increasing parity; compared with cows in parity 1, those in parity 4 had 5 or 7 times higher odds of having these lesions, respectively. Cows in mid lactation and late lactation had higher odds of sole ulcers and white line disease than cows at other stages of lactation, regardless of parity. Digital dermatitis prevalence was 2 times higher in herds housed in barns with access to an exercise area. The odds of sole ulcers and white line disease were ≥2 times higher in cows housed in freestalls than those housed in deep-bedded packs. Therefore, preventive measures for control of digital dermatitis merit emphasis, especially in primiparous cows and on farms with exercise areas. In addition, improving housing environment by providing a deep-bedded area for older cows in mid lactation or late lactation could reduce prevalence of claw horn lesions. We inferred that foot lesion data recorded by hoof trimmers can provide useful information not only to develop effective foot health programs at herd level, but also for disease surveillance and genetic improvement at regional and national levels.

In its simplest form, longevity is defined as the ability to live a long life. Within the dairy industry, longevity has been defined and measured in many different ways, and the aim of this review is to disentangle the definitions and provide some clarity. Using a more standardized approach for defining and measuring longevity, both in academic discussions and on-farm application, we suggest using herd life (days) for time from birth until culling, and length of productive life (days) for time from first calving until culling. Despite identified benefits of extending the length of productive life, global trends in the time spent by dairy cattle in the herd have mostly been negative. Factors influencing herd life, such as health, rearing, environmental conditions, and management, are often ignored when longevity goals are evaluated, thereby underestimating the effect these factors have on defining overall longevity. Also, production efficiency, herd profitability, and welfare are not necessarily served by the longest life but rather by the optimized length of herd life instead. The majority of research has focused on the role of genetics on longevity. In this review, we provide insight into influences affecting dairy cow herd life as well as farm- and cow-level factors associated herewith. Finally, we suggest using herd life, including reproduction, production, health, and youngstock performance, for farm-level evaluation and length of productive life for time spent in the lactating herd.

Lying behavior is an important measure of comfort and well-being in dairy cattle, and changes in lying behavior are potential indicators and predictors of lameness. Our objectives were to determine individual and herd-level risk factors associated with measures of lying behavior, and to evaluate whether automated measures of lying behavior can be used to detect lameness. A purposive sample of 40 Holstein cows was selected from each of 141 dairy farms in Alberta, Ontario, and Québec. Lying behavior of 5,135 cows between 10 and 120 d in milk was automatically and continuously recorded using accelerometers over 4 d. Data on factors hypothesized to influence lying behavior were collected, including information on individual cows, management practices, and facility design. Associations between predictor variables and measures of lying behavior were assessed using generalized linear mixed models, including farm and province as random and fixed effects, respectively. Logistic regression models were used to determine whether lying behavior was associated with lameness. At the cow-level, daily lying time increased with increasing days in milk, but this effect interacted with parity; primiparous cows had more frequent but shorter lying bouts in early lactation, changing to mature-cow patterns of lying behavior (fewer and longer lying bouts) in late lactation. In barns with stall curbs >22 cm high, the use of sand or >2 cm of bedding was associated with an increased average daily lying time of 1.44 and 0.06 h/d, respectively. Feed alleys ≥ 350 cm wide or stalls ≥ 114 cm wide were associated with increased daily lying time of 0.39 and 0.33 h/d, respectively, whereas rubber flooring in the feed alley was associated with 0.47 h/d lower average lying time. Lame cows had longer lying times, with fewer, longer, and more variable duration of bouts compared with nonlame cows. In that regard, cows with lying time ≥ 14 h/d, ≤ 5 lying bouts per day, bout duration ≥ 110 min/bout, or standard deviations of bout duration over 4 d ≥ 70 min had 3.7, 1.7, 2.5, and 3.0 higher odds of being lame, respectively. Factors related to comfort of lying and standing surfaces significantly affected lying behavior. Finally, we inferred that automated measures of lying behavior could contribute to lameness detection, especially when interpreted in the context of other factors known to affect lying behavior, including those associated with the individual cow (e.g., parity and stage of lactation) or environment (e.g., stall surface).