Investigating Ontario dairy farmers motivations and barriers to the adoption of biosecurity and Johne's control practices

Within-herd mathematical modeling of Mycobacterium avium subspecies paratuberculosis to assess the effectiveness of alternative intervention methods

Johne's disease (JD) in cattle is caused by Mycobacterium avium subspecies paratuberculosis (MAP) and is characterized by chronic, progressive enteritis that can lead to substantial weight loss, severe diarrhea, and eventual death. Economic losses due to JD are primarily driven by reduced milk production in subclinical and clinically infected cows, but also include reduced value when sold to slaughter, and costs associated with premature culling. Controlling the transmission of JD within a dairy herd can be achieved through proactive calf management practices and reactive test-based culling. While effective, test-and-cull interventions have the potential to result in net economic losses, particularly when the intervention includes culling of low-shedding cattle. Proactive calf management practices have been observed to be effective at controlling within-herd JD prevalence. However, assessing the magnitude of effect of interventions in observational and experimental studies can be difficult due to the pathogenesis of MAP and may take many years of data to provide meaningful results. The limitations of studying JD in nature presents an opportunity to use mathematical modelling techniques to assess the effectiveness of various interventions on the simulated within-herd disease dynamics of JD. The objectives of this study were to build a within-herd compartmental disease model of JD and assess the effectiveness of three interventions: 1) strategic insemination of test-positive low-shedding adult cattle to preferentially breed beef calves, 2) using separate calving areas for low- and high-shedding dams, and 3) test-based culling of low- and high-shedding cows. Model outcomes were compared to a base case model (i.e., no interventions) under four endemic within-herd prevalences. In general, simulations of test-based culling performed best at reducing long-term within-herd prevalence of JD. Strategic insemination and separate calving area interventions were both effective and performed similarly to one another, but even when combined were not as effective as test-and-cull alone. Finally, the results from the separate calving area intervention model suggest that increased dam-calf contact time would not result in a substantial increased within-herd prevalence. Given that some of the modelled populations in this study are very small and prevalence is very low, further work is needed to assess these interventions using discrete, stochastic methods, which may result in different outcomes.

Utilising on-farm risk assessment data for the management of Johne's disease in dairy cattle in Northern Ireland

Johne's disease (JD) causes weight loss, diarrhoea, and reduced milk yields in clinically infected cattle. In 2020, Animal Health and Welfare Northern Ireland (AHWNI) launched a voluntary JD control programme (JDCP) which focuses on bio-exclusion, biocontainment and market reassurance. Authorised veterinary practitioners (AVPs) conduct a Veterinary Risk Assessment and Management Plan (VRAMP) and use this information to make up to three recommendations. Between August 2022 and January 2024, 2274 herds enrolled in the NI JDCP and conducted up to three VRAMPs. This study characterised the JD-related risks and veterinary recommendations, identified the risks related to confirmed cases of JD and assessed if farmers changed their practices in response to AVP recommendations. AVPs assigned risk scores to management practices. Practices related to the calving area, particularly an absence of or delayed snatch calving, demonstrated the highest average risk score. Thematic analysis highlighted five main themes within AVP recommendations, including the use of diagnostic testing and management of calving areas. Multivariable binomial logistic regression identified five management practices which significantly increased the likelihood of herds having had a confirmed case of JD, including the segregation of clinically infected or test-positive cows from the rest of the herd in the calving area. Analysis of the risk scores and responses to closed questions from 278 herds which conducted first and second VRAMPs suggested that farmers had not changed their JD-related management practices in response to AVP recommendations. These findings simultaneously outline the challenges in JD control, reinforce the use of VRAMPs in identifying JD-related risks, demonstrate the harmonisation in AVP recommendation themes and provide data which can be considered by industry and policy makers.

'Implementation of bio…what?' Farm workers' subjectivities in Spanish dairy cattle farms through an ethnographic approach

This study explores the implementation of biosecurity measures by farm workers through daily work routines on dairy cattle farms in Spain. The implementation of biosecurity measures on dairy cattle farms is mainly decided by farmers and veterinarians, but it is carried out by both farmers and farm workers. However, farm workers may be affected by socio-employment factors such as the precariousness of their work such that implementation of biosecurity measures may be context dependent and may differ from official recommendations. An ethnographic approach was used through observations and conversations on four farms in two regions of Spain, two in Galicia (north-west) and two in Catalonia (north-east) to explore these factors. The profiles of participants were farmer-family workers, internal worker-employees and external worker-employees. Results showed that there were social differences, particularly communicative and hierarchical differences, between workers and farmers that influenced the implementation of biosecurity measures. Workers implemented biosecurity practices incompletely, differently or incorrectly from their supervisors' instructions. Workers also relied on what the authors called an anthropomorphic approach to implementing biosecurity measures, which deviated from farm guidelines. In order to improve the implementation of biosecurity measures on dairy cattle farms, it is necessary to consider workers as key stakeholders in biosecurity. Such consideration could also help to professionalise workers, reduce their turnover and increase their permanence on these farms.

Challenges for the management of Johne's disease in the UK: Expectation management, space, 'free riding', and vet-farmer communication

Johne's disease in cattle is a significant global animal health challenge. Johne's disease is chronic, affecting the gastrointestinal tract of cattle and other ruminants and is caused by the bacteria Mycobacterium avium ssp. Paratuberculosis. Many countries have introduced schemes and programmes to try and control the spread of Johne's disease, including the UK. Despite efforts to control it, however, Johne's disease remains consistently ranked by UK producers as the top ranked disease negatively affecting productivity, indicating that schemes are not perceived to have solved the problem fully. Building on a global systematic review of the literature on barriers and solutions for Johne's disease control on-farm, we conducted an empirical study with over 400 farmers and 150 veterinary professionals across the UK. The study used workshops and semi-structured interviews to understand better the challenges dairy farmers and veterinarians face in implementing on-farm Johne's disease management schemes with the aim of identifying solutions. The study found that four main challenges are faced in the on-farm control of Johne's - (1) Management of farmer expectations around Johne's disease, with eradication near impossible, (2) Issues regarding space for segregation and the related economics of control (3) A 'free-riding' problem which can be influenced by the voluntary nature of control plans and (4) Challenges in vet-farmer communication, including levels of knowledge. Our findings have relevance for the control of Johne's disease in the UK and other countries, including for regions with voluntary and compulsory control programmes.

Attitudes and professional values of veterinarians and veterinary students toward positive welfare states for dairy cattle

Research that involves agricultural animal welfare has typically aimed to improve welfare by decreasing disease, distress, and pain. Positive welfare does not necessarily occur with the absence of suffering but in combination with opportunities for behaviors or affective states desired by animals. Our objectives were to describe Canadian bovine veterinarians' and veterinary students' attitudes, professional normative values, and perceived ability to promote positive welfare for dairy cows, and to explore participants' provided rationale. With an online cross-sectional survey, Canadian veterinary practitioners (n = 78) and veterinary students (n = 148) were asked, on a 7-point Likert scale, about their attitudes, perceived professional normative values, and perceived ability of veterinarians to promote positive welfare for dairy cows. We used an applied thematic analysis approach within the qualitative description methodology to analyze participants' open-ended text responses. Quantitatively, participants had very favorable attitudes (mean ± SE; 6.3 ± 0.04) and perceived favorable values (5.7 ± 0.06) in the veterinary community toward positive welfare opportunities for dairy cows. Three themes were identified to explain the professional normative values: influences from within the veterinary profession, influences from outside the veterinary profession, and personal views of participants. Participants were confident that veterinarians could suggest positive welfare opportunities for dairy cows (6.1 ± 0.06) but were uncertain that the decision to suggest these opportunities to producers was within a veterinarian's control (4.3 ± 0.11) and were not confident that implementation of positive welfare opportunities was under a veterinarian's control (2.1 ± 0.07). Three themes were identified to explain the barriers to veterinarians promoting positive welfare opportunities for dairy cows: not practical to implement, resistance to change, and concern for the animal. Participants stated that many positive welfare opportunities were impractical or expensive to implement. We conclude that positive attitudes and positive professional values exist in the veterinary community toward positive welfare for dairy cows but that much uncertainty exists regarding a veterinarian's ability to influence change to current practices.

Assessing the impact of biosecurity practices and animal welfare in small-scale mountain dairy farming

This study estimates the association between the level of biosecurity, animal welfare, milk quality, and economic performance on 2291 mountain dairy farms which largely differs in management and structure from large dairy operations in the lowlands mainly due to climatic and topographic constraints in mountain areas. The dairy industry's increasing emphasis on biosecurity is crucial for ensuring animal health, productivity, and disease mitigation. Therefore, in the present study the biosecurity and animal welfare status of mountain dairy farms were assessed considering the official welfare protocol for dairy cows of the Italian ClassyFarm system. Our findings reveal a suboptimal adoption of biosecurity measures, attributed to structural limitations in mountain farms and farmers' awareness gaps. Despite these challenges, the economic significance of biosecurity adoption is evident, emphasizing potential benefits for farm viability and animal health. Conversely, the study indicates a moderate to good welfare status in assessed farms, reflecting farmers' awareness of the importance of high welfare standards for dairy cows. Improved welfare positively correlates with milk sales and productivity, highlighting the economic advantages of prioritizing animal well-being. Challenges persist, particularly regarding animal housing deficiencies and related consumer concerns about animal welfare in dairy production. Therefore, targeted interventions and educational initiatives are crucial to empower farmers and promote best practices in biosecurity and animal welfare management. However, addressing resultant production cost increases necessitates society's willingness to pay more for animal-based food, emphasizing the importance of aligning economic incentives with sustainable farming practices.

Investigating the Prevalence of Paratuberculosis in Hungarian Large-Scale Dairy Herds and the Success of Control Measures over Four Years

Paratuberculosis (PTB) is a severe, slow-developing, untreatable disease of ruminants. Worldwide, the disease affects more than 50% of herds in the dairy industry, and causes substantial economic losses for dairy producers. Diagnostic tests show limited sensitivity, especially in the early stages of the disease. Our study aimed to investigate the seroprevalence of Mycobacterium avium ssp. paratuberculosis (MAP) in large-scale dairy herds in Hungary, in association with the self-reported presence or absence of screening and intervention measures against MAP transmission. We processed data from 42 large-scale Holstein Friesian farms in Hungary between 1 January 2018 and 31 December 2021. An average of 32,009 (min.: 31,702; max.: 32,207) animals were blood sampled yearly (127,372 in total during the four years), corresponding to 15% of the Hungarian dairy cattle population. All female cattle older than 2 years were blood sampled on the farms enroled in the study. The samples were tested using a commercial ELISA (IDEXX paratuberculosis screening Ab test). Farm managers were interviewed about their on-farm diagnostic and intervention approaches using a uniform questionnaire, including questions on the level of awareness, frequency of ELISA and PCR testing, and their strategies for culling adult animals and reducing transmission to newborn calves. By comparing the annual rate of change in seroprevalence and the amount of change observed during the four-year period, we concluded that test-and-cull strategies implemented in parallel with newborn calf management that aimed at preventing MAP transmission were superior to test-and-cull strategies alone; moreover, fortifying culling decision making via additional ELISA and PCR tests is superior to using a single ELISA result. For farms that carried out a complex program with both "test-and-cull" and proper newborn calf management, there was a proportional reduction in apparent seroprevalence at an average of 22.8% per year. Fifteen of the sampled farms had no measures in place to control paratuberculosis. On these farms, the seroprevalence increased by 12.1% per year on average.