Caroline Ritter

Short communication: Herd-level prevalence of Mycobacterium avium ssp. paratuberculosis is not associated with participation in a voluntary Alberta Johne's disease control program.

Johnes disease (JD) control programs for dairy farms have the general objective of reducing both cow- and herd-level prevalence of Mycobacterium avium ssp. paratuberculosis (MAP). An important aspect of many programs is herd testing for MAP to determine the infection status of participating farms. However, it is uncertain whether MAP herd-level prevalence on farms voluntarily participating in a JD control program is different from that on nonparticipating farms. Therefore, the aim was to compare MAP infection status of participants and nonparticipants in the Alberta Johnes Disease Initiative (AJDI), a voluntary JD control program initiated in 2010 in Alberta, Canada. Between September 2012 and August 2013, environmental fecal samples were collected from 93 randomly selected farms not enrolled in the AJDI. Additionally, 81 farms that initially enrolled in the AJDI during the same time interval were also sampled. Samples were collected from 6 defined locations on each farm and cultured for MAP. Results were confirmed using conventional IS900 PCR and F 0285 quantitative PCR. Overall, 51% of participating and 51% of nonparticipating farms were identified as being MAP-infected. Furthermore, based on multivariable logistic regression, the number of MAP-positive samples was not associated with AJDI participation (taking herd size into account as a potentially modifying or confounding variable). In conclusion, there was no indication that voluntary participation in the AJDI was associated with herd-level MAP prevalence.

Action cameras and the Roter interaction analysis system to assess veterinarian-producer interactions in a dairy setting

Herd health and production management (HH&PM) are critical aspects of production animal veterinary practice; therefore, dairy veterinarians need to effectively deliver these services. However, limited research that can inform veterinary education has been conducted to characterise these farm visits. The aim of the present study was to assess the applicability of action cameras (eg, GoPro cameras) worn by veterinarians to provide on-farm recordings, and the suitability of these recordings for comprehensive communication analyses. Seven veterinarians each recorded three dairy HH&PM visits. Recordings were analysed using the Roter interaction analysis system (RIAS), which has been used to evaluate medical conversations in human and companion animal contexts, and provided insights regarding the importance of effective clinical communication. However, the RIAS has never been used in a production animal environment. Results of this pilot study indicate that on-farm recordings were suitable for RIAS coding. Dairy practitioners use a substantial amount of talk allocated to relationship-building and farmer education but that communication patterns of the same veterinarian vary considerably between farm visits. Consecutive studies using this method will provide observational data for research purposes and promise to aid in the improvement of veterinary education through identification of communication priorities and gaps in dairy advisory discussions.

Comparison of fecal pooling strategies for detection of Mycobacterium avium ssp. paratuberculosis in cattle

In herds with typical moderate to low within-herd prevalence, testing for Mycobacterium avium ssp. paratuberculosis (MAP), the infectious agent of Johnes disease, will be more cost-effective if individual fecal samples are cultured in composite pools. However, sensitivity to classify a pool containing 1 or more positive individual samples as positive may depend on pool size and number of individual positive samples within a pool. Fecal samples collected from 994 dairy cows sampled at slaughter were cultured to detect MAP. Culturing was done both individually and as composite pooled samples using the TREK ESP Culture System II broth medium (Thermo Fisher Scientific, Trek Diagnostic Systems Inc., Cleveland, OH). Composite samples consisted of pools containing feces from 3, 5, 8, 10, or 15 cows. The number of individual fecal culture-positive cows within each pool ranged from 0 to 4. Culture of individual fecal samples detected MAP in 36 (3.6%) of the 994 cows. Individual samples that were detected within the first 50 d by TREK ESP Culture System II were more likely to lead to a positive pool result. In total, 840 pooled fecal samples were examined for presence of MAP, and of those, 272 pools actually contained feces from fecal culture-positive cows. The crude sensitivity (proportion of pools that contained at least 1 fecal-positive cow that tested positive) for pools of 3, 5, 8, 10, and 15 was 47, 67, 44, 59, and 39%, respectively. Across pools, an increase of the number of fecal culture-positive samples from 1 to 2 enhanced overall crude sensitivity from 44 to 71%. However, sensitivity did not further increase for pools with 3 or 4 fecal culture-positive samples (63 and 60%, respectively). Additionally, a simulation analysis assessing probability of pooled fecal samples being positive in herds of 50 and 100 cows was conducted. The simulation assumed that 1, 2, or 5 cows per herd were MAP fecal culture-positive and that pools of 5 and 10 were used. This low-prevalence herd simulation indicated that weighted mean herd probabilities of detecting a positive herd ranged between 52 and 99.3%, with the lowest probability for pools of 10 with 1 positive cow in the herd and the highest probability for pools of 5 with 5 positive cows in the herd. However, overall, pools of 5 and 10 had similar diagnostic capabilities, enabling cost savings by utilizing pools of 10.

Evaluation by employees of employee management on large US dairy farms

Employees, many of whom are not native English speakers, perform the majority of work on large US dairy farms. Although management of employees is a critical role of dairy owners and managers, factors that improve employee engagement and retention are not well known. Objectives were to (1) identify key dairy farm employee management issues based on employee perceptions, (2) evaluate strengths and weaknesses of farms based on employee responses, (3) investigate differences between Latino and English-speaking employees, and (4) investigate differences in perception between employers and employees. Employees from 12 US dairy farms (each with a minimum of 10 employees) were interviewed by phone following a questionnaire provided. Employees provided their responses to 21 Likert scale questions and 8 open-ended questions. There was a wide range in employee turnover among farms (<10 to >100%). Latino employees had much shorter tenure and were more often employed in milking and livestock care than English-speaking employees. Employee perceptions differed among farms regarding whether they would recommend their farm as a place to work, teamwork within the dairy, whether rules were fairly applied, availability of tools and equipment, clear lines of supervision, and recognition for good work in the previous 15 d. Latino employees (n = 91) were more positive in many of these measures than their English-speaking counterparts (n = 77) but less often provided ideas to their employer on how to improve the business. Employers, surveyed on how they thought their employees would answer, underestimated employee responses on several questions, particularly the interest of employees in learning about dairy. When asked to cite 3 goals of the operation, there were differences among owners, managers, and employees. Although employees rated their commitment to the farm and their interest in learning as high, based on turnover, there was an obvious disparity between reality and ideal employee management. Consequently, employers should act on identified management shortfalls to improve employee retention.