Perceived role of the veterinarian in promoting dairy cattle welfare

Improving the lives of animals in agricultural systems has primarily focused on minimizing negative experiences. Research is needed on the promotion of positive experiences (pleasure, enjoyment, play, choice, happiness) for animals and the role of veterinarians in their promotion. Our aims were to describe how Canadian bovine veterinarians and veterinary students perceive the role of a veterinarian in positive vs. negative experiences for dairy cows and to analyze the rationale provided to explain their answers. Canadian veterinary practitioners (n = 78) and veterinary students (n = 148) responded to an online cross-sectional survey and were asked, on a 7-point scale, how important the role of a veterinarian is to promote practices that influence the experience of dairy cows. We used qualitative description to analyse participants' open-ended text responses. Practices to minimize negative experiences were most important (mean ± SE; 6.8 ± 0.03), a balance of positive and negative experiences was less important (6.4 ± 0.05), and encouragement of positive experiences scored lowest (6.0 ± 0.06), although all scored highly. Four themes were identified to explain participants' reasoning regarding their perceived role of a veterinarian in the promotion of dairy cattle welfare, centered on: the animal, the producer, the veterinarian, and society. Participants indicated that promoting positive experiences was less important than decreasing negative experiences (5.9 ± 0.09). There were four themes identified to explain participants' reasoning regarding the relative importance of promotion of positive experiences versus decreasing negative experiences which centered on: frameworks to compare positive and negative experiences, impacts on the animal, the participant's view of their role, and the practicality of implementation. These results indicate modest differences in valuing avoidance of negative vs. promotion of positive welfare. There were no differences in the quantitative analyses between veterinarians and veterinary students. We conclude that veterinarians are favorably disposed to positive aspects of welfare for dairy cows but may be more focussed on avoidance of negative aspects of welfare.

Factors influencing Scottish dairy farmers' antimicrobial usage, knowledge and attitude towards antimicrobial resistance

Understanding how farmers use antimicrobials and their awareness and beliefs about antimicrobial resistance (AMR) is essential to improve antimicrobial usage (AMU) practices and combat AMR on dairy farms. A cross-sectional online survey was carried out to identify the factors affecting attitudes, knowledge and behaviour of Scottish dairy producers regarding prudent AMU and the emergence of AMR in livestock. The survey was designed based on the earlier findings of two focus groups and was disseminated online via multiple methods (e.g., social media; farming press). Participation was voluntary and answers were obtained from 61 respondents (7.3% of the total population of Scottish dairy farmers). Logistic and ordinal regression analyses were performed to identify predictors for farmers' level of knowledge about antimicrobials and AMR, AMU behaviour and attitudes towards AMR mitigation. Associations were described with odds ratios (OR) and the associated 95% confidence intervals (95% CI). Farmers were more likely to have better knowledge of antimicrobials and AMR if they had undertaken a university degree (OR = 28.28, P < 0.001), worked with mixed livestock (dairy plus sheep/beef) (OR = 4.82, P < 0.05), and trusted only veterinarians' information about responsible AMU (OR = 4.42, P < 0.05). In the survey disease scenarios, younger farmers were less likely to be classed as low antimicrobial users (OR = 0.18, P < 0.05) compared to older farmers. Respondents working on larger herds were also less likely to be low antimicrobial users compared to those working on smaller herds (OR = 0.12, P < 0.01). Conversely, farmers who did not consider economic factors (e.g., cost and withdrawal period) in antimicrobial choice were more likely to be classed as low antimicrobial users (OR = 6.17, P < 0.01). Respondents were more likely to show positive attitudes towards AMR mitigation if they worked in larger (OR = 4.67, P < 0.05) or organic dairy farms (OR = 18.35, P < 0.05). These results suggest that several practices, social, demographic, and economic factors influence dairy farmers' perception and awareness of AMR and AMU. Efforts should be made to consider these variables when developing strategies to improve AMU in dairy farming. Veterinarians and advisors should focus AMU training and AMR awareness-raising activities towards younger, less experienced farmers as well as those with a lower educational qualification (high school vs. university degree). This study can inform the development of targeted educational initiatives to encourage responsible AMU on dairy farms.

Procalcitonin as an Endogenous Biomarker for Mastitis in Cows

Mastitis is one of the most common diseases of dairy cows. Procalcitonin (PCT) has been described as an endogenous inflammatory biomarker for bacterial infections. The aim of this study was to find possible correlations between PCT concentrations in the serum and milk of cows with mastitis and their clinical signs and disease progression. In total, 88 dairy cows were examined, of which 30 animals were diagnosed with clinical mastitis, 30 had subclinical mastitis, and 28 were designated as a healthy control group. The diseased animals were re-examined after 12 days. All PCT levels in this study were determined by a species-specific ELISA. All three groups could be differentiated from each other based on serum and milk PCT levels. The animals with clinical mastitis showed the highest mean concentrations of PCT (serum: 2641 pg/mL; milk: 1326 pg/mL), and the lowest PCT concentrations were found in the healthy control group (serum: 1166 pg/mL; milk: 176 pg/m). Over the course of the disease, results from the kinetics study showed that PCT levels remained high for the entire observation period. The results from this study showed that the PCT concentration could be used to differentiate between clinical mastitis, subclinical mastitis, and healthy cows.

Antimicrobial usage and resistance in scottish dairy herds: a survey of farmers' knowledge, behaviours and attitudes

Antimicrobial resistance (AMR) poses a major threat to global health. Understanding how antimicrobials are used on dairy farms and stakeholder beliefs relating to their use is essential to ensure responsible antimicrobial usage (AMU) to tackle the emergence of AMR. This study explored Scottish dairy farmers' knowledge about the meaning of AMR and antimicrobial activity, behaviour and practices related to farm AMU and attitudes towards AMR mitigation. An online survey was designed based on the findings of two focus groups and was completed by 61 respondents (7.3% of the total population of Scottish dairy farmers). Knowledge of antimicrobials and AMR was variable, and almost half of the participants believed that antimicrobials could have anti-inflammatory or analgesic activity. Veterinarians' opinions and advice about AMU were ranked significantly more important than other social referents or advisors. The majority of farmers (90%) reported having implemented practices to reduce reliance on antimicrobials (e.g., selective dry cow therapy, AMU treatment protocols) and having reduced farm AMU over recent years. Feeding waste milk to calves is still widespread, being reported by up to 30% of respondents. The main factors described to hinder responsible farm AMU were limited facilities (e.g., lack of isolation pens for sick animals) and knowledge of appropriate AMU recommendations, followed by time and financial constraints. Most farmers (89%) agreed that it is important to reduce AMU on dairy farms, but fewer (52%) acknowledged that AMU on UK dairy farms is currently too high, suggesting a mismatch between their intention to reduce antimicrobials and AMU behaviour. These results indicate that dairy farmers are aware of AMR, and their self-reported farm AMU has been reduced. However, some do not clearly comprehend the activity of antimicrobials and their correct usage. More work is needed to improve dairy farmers' knowledge of appropriate AMU and intentions to combat AMR. Farmers would benefit from more regular AMU discussions and advice from herd veterinarians, as they were described as highly trusted information resources. Training on how to reduce AMU should involve all farm staff administering antimicrobials and should be tailored to farm-specific barriers, such as limited facilities and workforce shortages.

A Survey of knowledge, attitude, and practices surrounding antimicrobial use by family dairy farmers to mastitis control

This study determined the family dairy farmers' knowledge, attitudes, and practices regarding the management strategy of mastitis, antibiotic use, and antimicrobial resistance in dairy farms in Türkiye. A total of 455 dairy farmers participated in face-to-face surveys from the villages of Çanakkale in Türkiye. A total of 62 questions that were divided into 5 categories were asked of the participants. Farmers (252/455; 55.4%) noted that they had not heard of any term about the expression of microbial resistance. They believe that antibiotic residues (156/455; 34,3%) do not pass into the soil and environment with animal wastes, and diseases such as mastitis (173/455; 38%) cannot be cured without antibiotics. Farmers indicated that they used antibiotic therapy in the treatment of udder diseases such as mastitis at a rate of 44.8%. Moreover, most dairy farmers (78.2%) decided to start antibiotic treatment with the decision of the veterinarian. Farmers believe that the barn environment is not as clean as necessary at a rate of 23.5%, and the necessary hygiene conditions are not followed in animal care 23.4% as the cause of mastitis. They highlighted that they detected mastitis from the redness or swelling of the udder at a rate of 38.2%. 55.8% of the farmers participating in the study had undergone analysis for the diagnosis of mastitis disease. On the other hand, 57.4% of farmers tried natural products such as olive oil, soft soap, vinegar, clay soil, honey, soapy, and yogurt, instead of antibiotics treatment for mastitis diseases. They have been relying mostly on veterinarian recommendations for AU. The use of culture and susceptibility test results for antimicrobial selection should be expanded among veterinarians. All stakeholders should be included in periodic training programs on topics such as AU, AR, preventive treatments for mastitis, vaccination, public health, and environmental health. Surveillance systems are needed to monitor AU and AR in animals, as in human medicine.

Selective treatment of nonsevere clinical mastitis does not adversely affect cure, somatic cell count, milk yield, recurrence, or culling: A systematic review and meta-analysis

Treatment of clinical mastitis (CM) contributes to antimicrobial use on dairy farms. Selective treatment of CM based on bacterial diagnosis can reduce antimicrobial use, as not all cases of CM will benefit from antimicrobial treatment, e.g., mild and moderate gram-negative infections. However, impacts of selective CM treatment on udder health and culling are not fully understood. A systematic search identified 13 studies that compared selective versus blanket CM treatment protocols. Reported outcomes were synthesized with random-effects models and presented as risk ratios or mean differences. Selective CM treatment protocol was not inferior to blanket CM treatment protocol for the outcome bacteriological cure. Noninferiority margins could not be established for the outcomes clinical cure, new intramammary infection, somatic cell count, milk yield, recurrence, or culling. However, no differences were detected between selective and blanket CM treatment protocols using traditional analyses, apart from a not clinically relevant increase in interval from treatment to clinical cure (0.4 d) in the selective group and higher proportion of clinical cure at 14 d in the selective group. The latter occurred in studies co-administering nonsteroidal anti-inflammatories only in the selective group. Bias could not be ruled out in most studies due to suboptimal randomization, although this would likely only affect subjective outcomes such as clinical cure. Hence, findings were supported by a high or moderate certainty of evidence for all outcome measures except clinical cure. In conclusion, this review supported the assertion that a selective CM treatment protocol can be adopted without adversely influencing bacteriological and clinical cure, somatic cell count, milk yield, and incidence of recurrence or culling.

A framework for evaluation of on-farm mastitis diagnostics in Australia

Numerous culture-based diagnostics are available on the Australian and international markets for on-farm detection of bacterial pathogens in milk. Use of such diagnostics may provide an opportunity to improve the prudent use of antimicrobials in udder health management. Farms are low-resource settings in terms of diagnostic microbiology capacity. The World Health Organisation has identified criteria for the evaluation of diagnostic tests in low resource settings based on Accuracy, Sensitivity, Specificity, User-friendliness, being Rapid or Robust, Equipment-free and being Deliverable (ASSURED). Here, we review how those criteria can be interpreted in the context of microbiological diagnosis of mastitis pathogens, and how on-farm diagnostics that are currently available in Australia perform relative to ASSURED criteria. This evaluation identifies multiple trade-offs, both with regard to scientific criteria and with regards to convenience criteria. More importantly, the purpose of testing may differ between farms, and test performance should be evaluated relative to its intended use. The ability of on-farm mastitis diagnostics to inform mastitis treatment decision-making in a timely and cost-effective manner depends not just on test characteristics but also on farm-specific pathogen prevalence, and on the farm enterprise's priorities and the farm manager's potential courses of action. With most assay evaluations to date conducted in professional laboratories, there is a surprising dearth of information on how well any of the diagnostic tests perform on-farm and, indeed, of the on-farm decision-making processes that they aim to inform.

Contextualized understandings of dairy farmers' perspectives on antimicrobial use and regulation in Alberta, Canada

Antimicrobial resistance (AMR) has been largely attributed to antimicrobial use (AMU). To achieve judicious AMU, much research and many policies focus on knowledge translation and behavioral change mechanisms. To address knowledge gaps in contextual drivers of decisions made by dairy farmers concerning AMU, we conducted ethnographic fieldwork to investigate one community's understanding of AMU, AMR, and associated regulations in the dairy industry in Alberta, Canada. This included participation in on-farm activities and observations of relevant interactions on dairy farms in central Alberta for 4 mo. Interviews were conducted with 25 dairy farmers. The interviews were analyzed using thematic analysis and yielded several key findings. Many dairy farmers in this sample: (1) value their autonomy and hope to maintain agency regarding AMU; (2) have shared cultural and immigrant identities which may inform their perspectives of future AMU regulation as it relates to their farming autonomy; (3) feel that certain AMU policies implemented in other contexts would be impractical in Alberta and would constrain their freedom to make what they perceive to be the best animal welfare decisions; (4) believe that their knowledge and experience are undervalued by consumers and policy makers; (5) are concerned that the public does not have a complex understanding of dairy farming and, consequently, worry that AMU policy will be based on misguided consumer concerns; and (6) are variably skeptical of a link between AMU in dairy cattle and AMR in humans due to their strict adherence to milk safety protocols that is driven by their genuine care for the integrity of the product. A better understanding of the sociocultural and political-economic infrastructure that supports such perceptions is warranted and should inform efforts to improve AMU stewardship and future policies regarding AMU.

Prevalence and Characterization of Serratia marcescens Isolated from Clinical Bovine Mastitis Cases in Ningxia Hui Autonomous Region of China

Purpose

This study aimed to investigate the prevalence and genetic characterization of Serratia marcescens isolates from clinical bovine mastitis in Ningxia Hui Autonomous Region of China.

Methods

S. marcescens was identified by the polymerase-chain reaction of 16S rRNA gene and sequencing. Antimicrobial susceptibility was tested by the disk diffusion method. Genes of resistance and virulence were determined by the PCR.

Results

Overall, S. marcescens were confirmed from 32 of 2897 (1.1%) mastitis milk samples. These isolates showed high resistance to cefazolin (30/32, 93.8%) and chloramphenicol (28/32, 87.5%). A 12.5% (4/32) of the isolates displayed multidrug resistance (MDR). The most prevalent resistant genes found in S. marcescens were TEM (32/32, 100%) and CTX-M (24/32, 75.0%; CTX-M-15, 14/32, 43.8%; CTX-M-14, 8/32, 25.0%; CTX-M-65, 2/32, 6.3%) for extended-spectrum beta-lactamase, cmlA (28/32, 87.5%) and floR (16/32, 50.0%) for chloramphenicol resistance, SIM-1 (2/32, 6.3%) for carbapenemases, and sdeB (28/32, 87.5%), sdeY (26/32, 81.3%), sdeR (26/32, 81.3%) and sdeD (20/32, 62.5%) for efflux pumps. Moreover, all isolates carried virulence genes flhD, entB, and kpn, and most of them contained mrkD (30/32, 93.8%), ycfM (26/32, 81.3%), bsmB (26/32, 81.3%), pigP (26/32, 81.3%), kfu (24/32, 75.0%) and shlB (24/32, 75.0%).

Conclusion

To our knowledge, this is the first report of genetic determinants for antimicrobial resistance and virulence in S. marcescens isolated from bovine mastitis cases in China. These findings are useful for developing strategies for prevention and treatment of bovine mastitis caused by S. marcescens in China.

β-defensin-4 as an endogenous biomarker in cows with mastitis

Introduction

Defensins are peptides with antimicrobial and immunomodulatory effects. Their concentration could be altered during infections and thus provide information on the prognosis and course of the disease. The aim of the present study was to investigate the defensin concentration in cows with mastitis in order to find correlations between clinical expression and course of the disease and the defensin concentration in milk and blood.

Methods

A total of 85 dairy cows were examined. Of these, 30 animals suffered from acute clinical mastitis, 25 animals were diagnosed with subclinical mastitis and 30 animals were considered a healthy comparison group. Beta-Defensin-4 (DEFB-4) was determined by a species-specific enzyme-linked immunosorbent assay (ELISA) (Bovine Defensin Beta 4 ELISA Kit, MyBioSource).

Results

The highest concentrations of DEFB-4 were detected in the animals with acute clinical mastitis. Values of 0 to 895 pg/mL (median: 115 pg/mL) were measured in milk and 40-1,016 pg/mL (median: 245 pg/mL) in serum. The concentrations of this group differed significantly from those of the animals with subclinical mastitis (p < 0.0001 serum; p = 0.015 milk). In this group, concentrations of 15-211 pg/mL (median: 46 pg/mL) were recorded in milk and 20-271 pg/mL (median: 85 pg/mL) in serum.

Discussion

Our results also show that in cases of acute mastitis after 12 days of treatment there is still an active inflammatory process in the tissue, because no significant reduction of somatic cells and defensin could be found after re-examination. Since the DEFB-4 concentrations of animals with clinical mastitis that had to be treated with antibiotics differed significantly from those of animals with subclinical mastitis that did not require antibiotic treatment, it can be assumed that bovine DEFB-4 is an important endogenous parameter for the defense against bacterial infections of the udder.

Realities, Challenges and Benefits of Antimicrobial Stewardship in Dairy Practice in the United States

The use of antimicrobials for the treatment of food-producing animals is increasingly scrutinized and regulated based on concerns about maintaining the efficacy of antimicrobials used to treat important human diseases. Consumers are skeptical about the use of antibiotics in dairy cows, while dairy producers and veterinarians demonstrate ambivalence about maintaining animal welfare with reduced antimicrobial usage. Antimicrobial stewardship refers to proactive actions taken to preserve the efficacy of antimicrobials and emphasizes the prevention of bacterial diseases and use of evidence-based treatment protocols. The ability to broadly implement antimicrobial stewardship in the dairy industry is based on the recognition of appropriate antimicrobial usage as well as an understanding of the benefits of participating in such programs. The most common reason for the use of antimicrobials on dairy farms is the intramammary treatment of cows affected with clinical mastitis or at dry off. Based on national sales data, intramammary treatments comprise < 1% of overall antimicrobial use for food-producing animals, but a large proportion of that usage is a third-generation cephalosporin, which is classified as a highest-priority, critically important antimicrobial. Opportunities exist to improve the use of antimicrobials in dairy practice. While there are barriers to the increased adoption of antimicrobial stewardship principles, the structured nature of dairy practice and existing emphasis on disease prevention provides an opportunity to easily integrate principles of antimicrobial stewardship into daily veterinary practice. The purpose of this paper is to define elements of antimicrobial stewardship in dairy practice and discuss the challenges and potential benefits associated with these concepts.

Understanding Vaccine Hesitancy in Vietnamese Fish Farmers

(1) Background: Antibiotic (AB) usage in food animals is a significant contributor to antimicrobial resistance (AMR). Vaccination can reduce the over-use of AB treatment. Little is known about farmers’ attitudes and beliefs about AB and vaccine usage in developing countries, especially in aquaculture. (2) Methods: We used the necessity/concerns framework to guide our research, where vaccine hesitancy is viewed as a function of the perceived necessity versus the perceived concerns about treatment. We measured disease and treatment perceptions in 400 Vietnamese farmers of Pangasius catfish, specifically regarding (a) chemical treatment of water, (b) antibiotic usage, and (c) vaccination of fish. (3) Results: Although farmers’ concerns about AB usage outweighed necessity beliefs, 86.5% reported having used ABs on their farm. Knowledge and attitudes towards vaccination were positive, with views of its necessity outweighing concerns. However, if available, only 67.6% said they would definitely use vaccines in the future. Farmers were more likely to use vaccines if they reported having fewer problems with fish disease, felt that any concerns about vaccines were outweighed by their perceived benefits, had less mistrust of vaccination, and had fewer concerns about commercial profiteering. (4) Conclusion: Interventions that highlight concerns about continued antibiotic use, reduce concerns, and mistrust and increase the perceived necessity of vaccines combined with greater availability of vaccines may be the most effective way of overcoming vaccine hesitancy and increase appropriate use of vaccines by Vietnamese fish farmers.

Integrated Bacteria-Fungi Diversity Analysis Reveals the Gut Microbial Changes in Buffalo With Mastitis

The gut microbial community is closely related to mastitis, but studies regarding the influences of mastitis on gut microbiota in buffalo remain scarce. Herein, we characterized the differences in gut bacterial and fungal communities between mastitis-affected and healthy buffalos. Interestingly, although mastitis had no effect on gut bacterial and fungal diversities in the buffalos, some bacterial and fungal taxa were significantly altered. Bacterial and fungal taxonomic analysis showed that the preponderant bacterial phyla (Firmicutes and Bacteroidetes) and fungal phyla (Ascomycota and Basidiomycota) in buffalo were the same regardless of health status. At the level of genus, the changes in some gut bacterial and fungal abundances between both groups were gradually observed. Compared with healthy buffalos, the proportions of 3 bacterial genera (uncultured_bacterium_f_Muribaculaceae, Eubacterium_nodatum_group, and Lachnoclostridium_10) and 1 fungal genus (Pichia) in the mastitis-affected buffalo were significantly increased, whereas 4 bacterial genera (Ruminococcus_2, Candidatus_Stoquefichus, Turicibacter, and Cellulosilyticum) and 4 fungal genera (Cladosporium, Thermothelomyces, Ganoderma and Aspergillus) were significantly decreased. Taken together, this research revealed that there was significant difference in the compositions of the gut microbial community between the healthy and mastitis-affected buffalos. To our knowledge, this is the first insight into the characteristics of the gut microbiota in buffalos with mastitis, which is beneficial to understand the gut microbial information of buffalo in different health states and elucidate the pathogenesis of mastitis from the gut microbial perspective.

Salvia miltiorrhiza polysaccharides ameliorates Staphylococcus aureus-induced mastitis in rats by inhibiting activation of the NF-κB and MAPK signaling pathways

The lactation capacity of dairy cows is critical to the productivity of the animals. Mastitis is a disease that directly affects the lactation capacity of cows. Staphylococcus aureus (S. aureus) is one of the most important pathogens that causes mastitis in dairy cows. The anti-inflammatory effect of Salvia miltiorrhiza polysaccharides (SMPs) has been demonstrated in mice and chickens. However, the effectiveness of SMPs in preventing and treating mastitis is unclear. Therefore, the purpose of this study was to explore the protective effect and mechanism of SMPs on mastitis caused by S. aureus. S. aureus was used to induce mastitis in rats, and three doses of SMPs (87.5, 175, 350 mg/kg, BW/d) were administered as treatments. The bacterial load, histopathology, and myeloperoxidase (MPO) and N-acetyl-β-D-glucosaminidase (NAGase) activities of mammary glands were observed and measured. Cytokines, including interleukin (IL)-1β, interleukin (IL)-6, and tumor necrosis factor α (TNF-α), were examined by qRT-PCR and ELISA. Key proteins in the NF-κB and MAPK signaling pathways were analyzed by Western blotting. The results showed that SMP supplementation could significantly reduce the colonization of S. aureus and the recruitment of inflammatory cells in mammary glands. S. aureus-induced gene transcription and protein expression of IL-1β, IL-6, and TNF-α were significantly suppressed in mammary glands. In addition, the increase in NF-κB and MAPK protein phosphorylation was inhibited by SMPs. These results revealed that supplementation with SMPs protected the mammary gland of rats against damage caused by S. aureus and alleviated the inflammatory response. This study provides a certain experimental basis for the treatment of S. aureus-induced mastitis with SMPs in the future.

Udder health, conceptual construct, and uses of the term: A systematic review from 1962 to 2019

Background and Aim:

Udder health management is essential for the further development of milk production systems and public health. This process depends on the generation of knowledge regarding control, prevention, and promotion of health. In scientific literature, it is impossible to find a synthesis of the categories that would allow comprehension of the complex phenomenon udder health. Different research approaches have allowed this polysemic concept, described by some researchers as multifactorial and by philosophical perspectives as a social phenomenon, to be further studied. Thus, the objective of this systematic review was to systematize the conceptual categories of udder health and the use of the term in the original articles published in the scientific literature from the period 1962 to 2019.

Materials and Methods:

A systematic review with a broad approach was designed by applying the phases of identification, screening, selection, and inclusion criteria described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes guide. An exhaustive search of original articles by specificity was carried out in the Science Direct, PubMed, Scielo, LILACS, and Google Scholar databases. The investigation was carried out on November 22, 2019. According to the inclusion criteria established, articles needed to be original studies, to be publications on bovine livestock, written in English, Spanish and Portuguese. Furthermore, the articles considered needed to tackle the term udder health so that its conceptual categorization could be extracted. Google Scholar patents and citations and articles removed from databases or not available were excluded from the study and those that, based on the reading of the complete text, considered the farming of animal species other than bovine. A qualitative synthesis of the year of publication, continent, approach, type of study, and conceptual category of udder health was carried out by calculating frequencies (Statistical Package for the Social Sciences version 24).

Results:

In total, 165 articles were included in the study. Eight conceptual categories, consolidated over time, were systematized, showing that udder health is not a static problem, and that science has been responding through the generation of new knowledge around conceptual categories as different udder health problems emerge.

Conclusion:

Culture and politics were two categories, related to all the others, that stood out in the results. These two categories were of great interest in countries advanced in milk production and in the implementation of udder health policies, which acknowledge the producer and other actors of the production chain as fundamental political actors for policies, decision-making processes, and public health care to be effective. The lack of synonyms for the term udder health (e.g., mastitis) may have led to the exclusion of important articles in each category. However, the constriction to the term udder health was intentional and aimed at constructing the concept. Udder health is hereby understood as a health-disease process, different from the term mastitis, which from its semantic origin, refers only to the disease process. According to this study, the concept can be understood through the categories of traditional epidemiology based on risk factors and disease; microbiology; genetics, resistance, and immunity; animal welfare; nutrition; organic production; culture; and politics.

Knowledge, attitudes, and perceptions of dairy farmers regarding antibiotic use: Lessons from a developing country

In lower- and middle-income countries, uncontrolled use of antibiotics is causing antimicrobial resistance, affecting both animal welfare and public health. Meanwhile, studies on antibiotic use in these countries are limited. A crucial step to limit the spread of antimicrobial resistance (AMR) is to examine the use of these drugs and identify its determinants. The aim of our study, the first of its kind in Lebanon, was to assess dairy farmers' knowledge and awareness of antimicrobial use (AMU) and AMR. For this, 18 farmers from different regions, educational backgrounds, experience levels, and herd sizes were interviewed. Results showed that owners of larger farms were more aware of AMU and AMR, and trying to implement preventive actions, whereas nonsystematic antimicrobial use was prevalent among the smaller farms. Mastitis and laminitis were the most treated diseases, and antibiotics used were oxytetracycline, penicillin, streptomycin, and florfenicol. Overall, antibiotic use was found as a preventive measure and a treatment of nonbacterial diseases. Irregular uses were linked to easy access of farmers to antibiotics, interrupted relations with veterinary authorities, and lack of self-assessment and inspection. Lebanese dairy farmers and owners reported feeling disadvantaged in their local trade field, facing illegal competition and unauthorized farms and industries, and lacking support from the government. Training and awareness programs must be implemented, and policies and regulations must be set, to reduce antibiotic use and hinder the spread of AMR in Lebanon.

Antimicrobial use in agriculture: critical review of the factors influencing behaviour

Antimicrobial resistance (AMR) is a global health emergency affecting humans and animals, diminishing the effectiveness of medication used to treat illness. The agri-food sector has attracted increased attention for imprudent antimicrobial use (AMU) and its contribution to AMR. Thus, ascertaining farmers' and veterinarians' behaviours surrounding AMU is essential to address imprudent AMU and generate behaviour change within the agri-food sector. Therefore, the aim of this critical review is to investigate, assess and collate the current body of evidence to identify psychosocial factors including knowledge, understanding, perceptions, attitudes and behaviours surrounding AMU. Database searches were limited to articles utilizing qualitative and quantitative methodologies, available in English with no restriction on publication year. Of the 1156 articles identified, 103 were retained for this review. Findings on the psychosocial aspects were thematically analysed. Five key themes emerged from the data: (i) knowledge and awareness of antimicrobials; (ii) attitudes towards antimicrobials; (iii) influential relationships; (iv) resources; and (v) factors influencing AMU. Results indicated that to overcome barriers experienced by key stakeholders, a carefully considered, evidence-based approach, incorporating behaviour change theory, is required when designing intricate interventions/strategies, in order to elicit successful and sustained AMU behaviour change.

The Impact of Experiences and Perceptions of Highly Pathogenic Avian Influenza (HPAI) on Water-Related Biosecurity Behaviour in Rural Vietnam

BACKGROUND

In Southeast Asia from 2004 to 2006, highly pathogenic avian influenza (HPAI) resulted in culling 45 million birds and jeopardizing sustainable agricultural production. HPAI is highly virulent; small-scale farms present a high-risk environment for disease transmission between animals and humans. We investigated how attitudes toward HPAI influence water-related biosecurity mitigation behaviors on small-scale farms in Vietnam using the conceptual framework Social Cognitive Theory.

METHOD

We analyzed a secondary cross-sectional data set from northern (Thai Binh) and southern (An Giang) provinces in Vietnam, describing a stratified randomized selection of 600 small-scale farmers who were interviewed using questionnaires and in-person interviews. Logistic regression analysis and odds ratios were used to examine relationships between factors influencing HPAI attitudes, social norms, perceived importance, and behaviors (α = 0.10) RESULTS: Concern about the severity of HPAI was significantly associated with increased perceived importance for all water management biosecurity methods (p < 0.01). Media and/or peer influence had negative effects on perceived importance to practice water-related biosecurity (p < 0.10). High importance of practice water-related biosecurity resulted in high uptake (p < 0.05). Past experiences with HPAI were significant in predicting perceived importance; none were significant in describing behavior uptake.

DISCUSSION

Biosecurity guidelines may not be consistent with management styles of Vietnamese small-scale farms; perceived importance of a behavior may be an important mediating variable. Gaps exist in uptake of water management practices as biosecurity for HPAI, potentially negatively affected by peer and media influence. Our results should be of interest to public health and policy authorities addressing HPAI mitigation.

Engaging with selective dry cow therapy: understanding the barriers and facilitators perceived by Irish farmers

BACKGROUND

Selective dry cow therapy (SDCT) is widely promoted in dairy farming as a method to reduce antimicrobial usage. New legislation introduced by the European Union will restrict and regulate the prophylactic and metaphylactic use of antibiotics from January 2022. Blanket dry cow therapy continues to be a practice engaged in by many farmers in Ireland and for many of these farmers, moving towards SDCT would require a significant infrastructural, behavioural and/or cultural change on their farm. Existing research has reported the important need to understand farmers' motivations to initiate any substantial behaviour change. However, it is currently unknown what farmers know, think and believe about SDCT in Ireland. The aim of this study was to use qualitative methods to explore what barriers and facilitators farmers perceived to exist with SDCT and explore if they had chosen to implement SDCT after voluntarily participating in a funded dry cow consult with a trained veterinarian, with the objective of maximising the dry period udder health performance and moving safely to SDCT.

RESULTS

In this study, 19 farmers were contacted, and telephone interviews were conducted regarding farmers' beliefs about the consequences of SDCT. Audio recordings were professionally transcribed verbatim and analysed qualitatively using an inductive thematic analysis. The analysis identified 6 barriers and 6 facilitators to implementing SDCT. A significant fear of increasing mastitis incidence was evident that caused reluctance towards SDCT and reliance on antibiotics. Mixed perceptions on SDCT, infrastructure limitations, a perceived lack of preventive advice as well as peer influence were presented as barriers to SDCT. Farmers can build confidence when a graded approach to SDCT is implemented, which could help overcome the fear of SDCT and reliance on antibiotics. Regulatory pressure, high standards of farm hygiene and use of targeted veterinary consults were found to facilitate SDCT. Education was suggested to motivate farmers in the future uptake of SDCT. Despite cited negative influences, peer influence can be utilised to encourage the farming community.

CONCLUSIONS

This study prioritises areas to facilitate the major behaviour change required as a dairy industry in order to move from blanket dry cow therapy to SDCT.

Social referents for dairy farmers: who dairy farmers consult when making management decisions

Social referents provide information that aid in farmer decision making. Some social referents, such as veterinarians, have been well studied in the context of dairy farms, but others have not and the role of social referents may change across management practices. This study aimed to understand (1) who farmers consult when making management decisions across different animal care practices and (2) what characteristics of these social referents influence farmer decision making. Secondary thematic analysis was used on two qualitative datasets with dairy farmers from the lower Fraser Valley region of British Columbia, Canada. The two datasets included non-naturalistic data (i.e. interviews, participatory discussion groups) investigating two dairy farm management practices (calf care and transition period management). Analysis revealed four themes: (1) who farmers consult when making management decisions across practices and the role of these social referents, (2) personal and professional characteristics, and the diversity of opinions of social referents, (3) actions of social referents, and (4) the strength of the relationship between the social referent and farmer. Similarities were found across practices regarding the personal and professional characteristics of social referents, even though the role of these referents varied across contexts. Farmers valued diverse opinions and actions that social referents could provide, such as the provision of resources, recommendations, and interpretation of farm data. We recommend future research focused on strengthening the relationship between farmers and social referents.

The antimicrobial landscape as outlined by Danish dairy farmers

Limiting antimicrobial use (AMU) in dairy farming is an important step toward reducing antimicrobial resistance (AMR). Therefore, it is relevant to understand dairy farmers' choices and the potential for change in relation to AMU, even in countries with low usage. Furthermore, there is an increasing recognition of the need to focus on both the individual farmer's behavior as well as the context surrounding and influencing the farmer's decisions in relation to AMU if the goal is further reduction. To date, no studies have taken into account both the individual farmer and their context in both conventional and organic dairy farms under Danish conditions. For this study, 15 Danish dairy farmers were interviewed using qualitative semi-structured research interviews, and the notion of landscape was used to describe the context of their AMU. We found that AMR was considered a distant element of the farmers' antimicrobial landscape. Daily challenges such as acutely diseased animals and poor housing conditions seemed more urgent and overruled the threat of AMR. We also found that interviewed farmers had differing opinions on farm management, partly shaped by changes in legislation and ways of farming over time. At one end of the scale, some organic farmers had rethought the current way of farming; keeping robust animals in a natural setting was expected to prevent disease. They were positive about legislation, and the numerous restrictions on AMU over time were thought to contribute to ensuring quality for consumers. At the other end of the scale, some conventional farmers perceived disease as something that should be controlled through treatment, and the currently eased legislation and intensification of farming have legitimatized AMU for this purpose, leading to an expectation among these farmers of certain rights to handle medicines themselves. These contrasting views might lead to inspiration and competition in terms of reducing AMU, as the farmers appeared to value the opinions of other farmers, and they were found to continuously assess each other. Through such ongoing assessment, pioneers of AMU reduction-whether organic or conventional-might motivate their colleagues to change their AMU. Future research should address the potential of experience- and attitude-sharing among farmers as motivation to reduce AMU.

A Focus Group Study of Canadian Dairy Farmers' Attitudes and Social Referents on Antimicrobial Use and Antimicrobial Resistance

As part of broader actions to combat antimicrobial resistance (AMR), health authorities have promoted the reduction of antimicrobial use (AMU) in food animals. Farmers' attitudes and receptivity to reduction of AMU appear to be variable and context specific. Our research objectives were to gain insight into Canadian dairy farmers' attitudes toward AMU, AMR, and AMU-reduction in the dairy industry, and to explore drivers and barriers to change AMU, including the influence of social referents. We conducted seven focus groups with 42 farmers in two provinces of Canada (New Brunswick and Ontario) and used thematic analysis to identify, analyze, and report patterns in the data. Our results indicate that farmers usually rely on their previous experience and judgement of individual cases of disease when making decisions related to AMU. External referents included other farmers, family members, and veterinarians. However, veterinarians were generally only consulted for unusual cases. Participants in this study expressed that maintaining cattle welfare is their responsibility, and that they were not willing to jeopardize animal welfare in order to reduce AMU. In addition, farmers regarded the cost of investment in improved facilities to prevent disease as an important barrier to reduce AMU. Finally, the majority of participants considered themselves to be low users of antimicrobials and perceived a small role of AMU on dairy farms in AMR. In conclusion, farmers from this study showed self-reliance to decide about AMU on their farms and considered animal-related and economic factors in these decisions. There was a general lack of knowledge of how to reduce AMU without investing in facilities, and there is an opportunity to motivate increased involvement of the veterinarian in AMU-related decisions. These results should be considered to design and refine antimicrobial stewardship programs for dairy farms.

From the other perspective: Behavioural factors associated with UK sheep farmers' attitudes towards antibiotic use and antibiotic resistance

Research suggests that many sheep farmers continue to carry out traditional antibiotic use practices despite new ’good practice’ recommendations. The aim of this study was to group farmers depending on their attitudes around antibiotic use and antibiotic resistance, and determine the behaviours that are associated with the farmers in these groups. In 2017, a flock health survey was sent to British sheep farmers. K-means cluster analysis was used to identify groups of farmers with similar attitudes towards antibiotic use and resistance. A multivariable logistic regression model was built to determine the associations between farmers’ past behaviours and their antibiotic attitude group. There were 461 responses. Two groups of farmers were identified based on their antibiotic attitudes. Cluster 1 were defined as the "discordant" group who had positive views of using antibiotics prophylactically and negative views of reducing antibiotic use. Cluster 2 were defined as the "concordant" group who were positive about reducing antibiotic use and had negative views about using antibiotics prophylactically. Using antibiotics in all lambs (OR = 2.689, CI = 1.571, 4.603), using antibiotics in all ewes (OR = 3.388, CI = 1.318, 8.706), always trimming diseased feet over the past three years (OR = 2.487, CI = 1.459, 4.238), not using a computer to record information over the past three years (OR = 1.996, CI = 1.179, 3.381), not changing worming practices over the past three years (OR = 1.879, CI = 1.144, 3.087), and farmers’ perceptions that their sheep flock did not make a financial loss in the past three years (OR = 2.088, CI = 1.079, 4.040) were significantly associated with belonging to the discordant group. Talking to their veterinarian about antibiotic use or the frequency of veterinary visits were not associated with antibiotic attitude group. These results suggest that farmers who had attitudes relating to antibiotic use that did not align with current recommendations carried out more traditional practices, which were strengthened by their positive perceptions of profitability.

Why do Irish pig farmers use medications? Barriers for effective reduction of antimicrobials in Irish pig production

Background

In addressing the threat of antimicrobial resistance, it is critical to understand the barriers to the uptake of strategies for the reduction of antimicrobial use (AMU) in the pig industry. In several EU countries, factors such as education level, habits and social pressures are recognised as affecting farmers’ decision-making process in relation to AMU. However, there is a lack of information on the Irish scenario. The aim of this study was to investigate pig farmers’ perspectives and their behaviour towards AMU to identify potential barriers to effectively reduce AMU in Irish pig production. We conducted face-to-face semi-structured interviews with 30 pig farmers, 5 pig veterinarians and 4 focus groups of pig farm personnel. We employed qualitative analyses to explore the objective of the study.

Results

Qualitative analysis revealed six convergent themes as potential barriers: perceptions about the need for AMU on farm, concept of animal welfare and associated management practices, legislation, culture, economics and standards of communication/type of advice-network. Overall, pig farmers believed that there is poor communication between stakeholders (i.e. farmers, vets and advisors) and a lack of reliable people to approach for advice. They considered themselves as operating responsibly in terms of AMU compared to their national and international colleagues and expressed the importance of a so-called ‘Irish solution’ to the problem of AMU because it was associated with what ‘has always been done’ and was therefore considered reliable and safe.

Conclusions

Barriers and challenges were in line with those identified in other EU countries highlighting similarities in behavioural and attitudinal patterns among pig farmers. Overall, farmers appeared to be more likely to rely on previous experiences or to wait for an imposed change (e.g. legislation) instead of taking personal action. Thus, considerable behavioural and attitudinal changes are needed to adopt a more responsible AMU in Irish pig production and to develop effective intervention strategies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13620-021-00193-3.

Dairy cow health and management in the transition period: The need to understand the human dimension

During the transition from the dry period to lactation the dairy cow undergoes a period of physiological, metabolic and immunological change, and is at greater risk of developing disease, to the detriment of health, welfare and production. Many studies have been undertaken to determine appropriate management strategies to improve health and welfare during the transition period, however the incidence of disease, particularly metabolic disease, in this period remains high. To date, a lack of research attention has been paid to the social factors which may affect the management of transition dairy cows. An understanding of farmer and advisor attitudes and behaviour, and the challenges they face in managing transition cows, may help to direct farmers towards more effective disease prevention and control. It is also possible that transition cow morbidity may be due to complex interactions that are difficult to manage, despite efforts to implement best practice. This review paper provides a brief overview of some of the management factors that may influence herd health during the transition period. It then investigates how social influences may relate to the uptake of transition management practices by exploring the use of qualitative interviews investigating farmer and stakeholder attitudes and behaviour in relation to cattle health and welfare, before focussing more specifically on farmer behaviour. Additionally, this paper explores farm advisor behaviour, and how that has been shown to influence farmer adherence to advice, which has particular relevance to transition cow management. It then suggests potential research strategies to investigate the human influences affecting the scale of the problem that may provide solutions to tackle the challenge of improving dairy cow health and welfare.

Farmer perceptions of dairy farm antibiotic use and transport pathways as determinants of contaminant loads to the environment

Agricultural antibiotic contamination into milk and beef products has been considered extensively, but antibiotic transport into soil and water environments is less regulated and studied. Farmer perceptions of these transport processes are critical to understanding how antibiotics reach soils and surface waters and what management strategies can be implemented to reduce environmental antibiotic loads. We have conducted semi-structured interviews with twenty-seven dairy farmers in central New York to understand farmer perceptions of environmental transport of antibiotics and decisions that reduce environmental antibiotic loads. Interviews were qualitatively analyzed and coded using thematic analysis. We found that farmers extensively considered transport of antibiotics into milk and beef, while consideration of antibiotic transport into manure was less common, and no farmers discussed antibiotic transport from carcasses into soil from on-farm animal mortality. Farmers highlighted decisions that reduce antibiotic environmental loads through disease prevention actions, usage of non-antibiotic treatments, and culturing bacterial samples before antibiotic treatment. Farmers did not cite reduction of environmental antibiotic loads as a driver of their waste management decisions. Farmers perceived antibiotic usage was already minimized on farms in the region, suggesting future environmental antibiotic contamination mitigation strategies should focus on waste management pathways.

Understanding farmers' and veterinarians' behavior in relation to antimicrobial use and resistance in dairy cattle: A systematic review

To tackle antimicrobial resistance, it is vital that farmers' and veterinarians' antimicrobial use behaviors and attitudes toward resistance are understood so that we can identify how beliefs and motives influence practices. Current literature details qualitative and quantitative research that explores the knowledge, attitudes and perceptions of dairy farmers and veterinarians with respect to antimicrobial resistance and antimicrobial practices, and the reported findings are varied and conflicting. Our objective was to conduct a systematic review to assess the evidence and knowledge gaps in the published literature. We identified articles via database searches of Embase, Medline, PubMed, Scopus, and Web of Science; we limited findings to published articles available in English with no publication year restrictions. Article screening was conducted at 3 levels: title, abstract, and full text. Of the 349 articles identified, 35 were retained for systematic review. Transparency of reporting was assessed for each study using the Consolidated Criteria for Reporting Qualitative Research (COREQ) framework. Quality was assessed using the Critical Appraisal Skills Programme qualitative checklist. Findings relating to dairy farmers' and veterinarians' knowledge, attitudes, and perceptions on antimicrobial resistance and practices were thematically analyzed. The comprehensiveness of reporting was variable: studies reported 5 to 26 of the 32 COREQ checklist items. Five key themes emerged from the data: knowledge and awareness of antimicrobial resistance; factors influencing farmer and veterinarian decision-making; perceived barriers and facilitators to reduced antimicrobial use; perceived responsibility for antimicrobial resistance; and the role of the farmer and veterinarian relationship in reducing antimicrobial use. Awareness of prudent antimicrobial use was not uniform between studies. Many factors influence farmers' and veterinarians' decisions to use antimicrobials, including animal welfare and available resources. The farmer-veterinarian relationship is a potential barrier or facilitator of reduced antimicrobial use, depending on the perceived relationship dynamic. Encouraging collaboration between farmers and veterinarians could lead to shared responsibility for reducing antimicrobial use. This review provided a coherent picture of what is currently known and identified gaps in the current knowledge to inform future behavioral intervention research. Increased knowledge, skill development, resources, engagement, and further research to address the gaps we identified are the main recommendations to effectively overcome barriers, elicit appropriate behavior change, and achieve reduced antimicrobial use in dairy cattle.

Sheep farmers' attitudes towards lameness control: Qualitative exploration of factors affecting adoption of the lameness Five-Point Plan

In 2014, best-practice recommendations to treat and control lameness in sheep in the UK were consolidated into a national program, the Five-Point Plan (5PP). As recent evidence suggests that only the minority of sheep farmers are implementing all management practices listed in the 5PP, qualitative investigation is vital to ensure future promotion is aligned with psychological and contextual factors affecting farmers’ decision-making. This qualitative study sought to explore farmers’ attitudes and the factors affecting uptake of best-practice measures listed in the 5PP. Semi-structured interviews were conducted in 2019 with 12 sheep farmers from England and Wales. In accordance with Thematic Analysis and the principles of Grounded Theory, data collection and analysis were performed iteratively. Two overarching themes, delineated by subthemes, emerged during analysis; (1) Barriers to adoption of 5PP measures and (2) Motivation to adopt 5PP measures. Various farmer-centric factors and physical resources were identified as key barriers or obstacles that limited farmers’ ability to implement 5PP measures outright, or restricted their ability to make changes to facilitate future adoption. Conversely, internal and external influences were identified to increase farmers’ willingness and motivation to implement practices listed on the 5PP. Heterogeneity in farmer perceptions, attitudes, experiences and circumstances identified in this study highlights the difficulty in promoting a one-size-fits-all lameness control plan, where a unique combination of intrinsic factors, social influences, and physical restrictions affect implementation. Future initiatives should focus on removing barriers by changing farmers’ perceptions and mindset towards lameness control, and building farmers’ confidence in their ability to implement practices. Furthermore, farmers’ social licence to farm and their desire to improve their reputation within society, presents an important opportunity to further engage farmers in implementing control practices. Increasing peer-to-peer knowledge transfer opportunities and effective farmer-veterinarian communication and rapport could help establish 5PP measures as normative behaviours.

Veterinary Herd Health Consultancy and Antimicrobial Use in Dairy Herds

The globally increasing level of antimicrobial resistance affects both human and animal health, why it is necessary to identify ways to change our current use of antimicrobials. The veterinary herd health collaboration between veterinarians and dairy farmers provides a useful setting for changing antimicrobial use in livestock. However, farmers and veterinarians work in a complex agricultural setting influenced by socio-economic factors, which complicates their choices regarding antimicrobial usage. It is therefore necessary to be aware of the range of potential influencing factors and to integrate this knowledge in the relevant local settings. This manuscript presents a literature review of relevant factors relating to antimicrobial use within the veterinary herd health consultancy setting, including knowledge gaps of relevance for changing the use of antimicrobials. An enriched version of the framework of the Theory of Planned Behaviour was used to organise the literature review. We identified diverging attitudes on correct treatment practices and perceptions of antimicrobial resistance among veterinarians and farmers, influenced by individual risk perception as well as social norms. Furthermore, disagreements in terms of goal setting and in the frequency of herd visits in relation to herd health consultancy can negatively influence the collaboration and the intention to change antimicrobial use. Farmers and veterinarians emphasise the importance of legislation and the role of the dairy industry in changing antimicrobial use, but the relevance of specific factors depends on the country-specific context. Overall, farmers and veterinarians must communicate better to understand each other's perspectives and establish common goals within the collaboration if they are to work efficiently to reduce antimicrobial use. Farmers and veterinarians both requested changes in individual behaviour; however, they also called for national and structural solutions in terms of balanced legislation and the availability of better diagnostics to facilitate a change in antimicrobial use practices. These various paths to achieving the desired changes in antimicrobial use illustrate the need to bridge methodological research approaches of veterinary science and social sciences for a better understanding of our potential to change antimicrobial use within the dairy farm animal sector.

The value of the biomarkers cathelicidin, milk amyloid A, and haptoglobin to diagnose and classify clinical and subclinical mastitis

Timely and objective diagnosis and classification of mastitis is crucial to ensure adequate management and therapeutic decisions. Analyzing specific biomarkers in milk could be advantageous compared with subjective or semiquantitative criteria, such as palpation of the udder in clinical mastitis cases or evaluation of somatic cell count using cow side tests (e.g., California Mastitis Test) in subclinical mastitis quarters. The objective of this study was to investigate the diagnostic value of 3 biomarkers; cathelicidin, milk amyloid A, and haptoglobin for the diagnosis of subclinical and clinical mastitis. Furthermore, the suitability of these biomarkers to differentiate between mild, moderate, and severe clinical mastitis and the influence of different pathogens on biomarker levels was tested. A total of 67 healthy cows, 119 cows with subclinical mastitis, and 212 cows with clinical mastitis were enrolled in the study. Although cathelicidin, haptoglobin, and milk amyloid A were measured in all samples from healthy cows and those with subclinical mastitis, haptoglobin, and cathelicidin results were only available from 121 out of 212 cows with clinical mastitis. Milk amyloid A was measured in all samples. In cows with clinical mastitis, the mastitic quarter and a second healthy quarter serving as a healthy in-cow control quarter were sampled. It was possible to differentiate between healthy quarters, quarters with subclinical mastitis, and quarters with clinical mastitis using all 3 biomarkers. Concerning cathelicidin, thresholds were 0.000 [sensitivity (Se) = 0.83, specificity (Sp) = 0.97] and 0.053 (Se = 0.98, Sp = 0.99) for normalized optical density at 450 nm (NOD450) for differentiating between healthy quarters and quarters with subclinical or clinical mastitis, respectively. Thresholds of 1.28 µg/mL (Se = 0.65, Sp = 0.76) and 1.81 µg/mL (Se = 0.77, Sp = 0.83) for milk amyloid A and 3.65 µg/mL (Se = 0.92, Sp = 0.94) and 5.40 µg/mL mL (Se = 0.96, Sp = 0.99) for haptoglobin were calculated, respectively. Healthy in-cow control quarters from cows with CM showed elevated milk amyloid A and haptoglobin levels compared with healthy quarters from healthy cows. Only the level of milk amyloid A was higher in severe clinical mastitis cases compared with mild ones. In contrast to clinical mastitis, cathelicidin and haptoglobin in subclinical mastitis quarters were significantly influenced by different bacteriological results. The measurement of cathelicidin, milk amyloid A, and haptoglobin in milk proved to be a reliable method to detect quarters with subclinical or clinical mastitis.

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.

Communication preferences and social media engagement among Canadian dairy producers

The objective of this study was to determine communication preferences of dairy producers in Canada. A secondary objective was to evaluate social media engagement of dairy producers. A survey was administered to Canadian dairy producers between March and April, 2015 to collect information on current management practices on their farms. A total of 1,373 Canadian dairy producers responded to the survey, representing a response rate of 12%. The survey consisted of 192 questions; however, only questions regarding producer demographics, importance of information sources, and internet and social media use were evaluated in this study. The primary outcome variables of interest included use of the internet to access dairy information, importance of different sources of information about dairy herd health and management, and use of online search engines and social media platforms. For each outcome, logistic regression analyses were used to investigate associations between the outcome and demographic variables. Veterinarians were viewed as a "very important" source of information by the majority of respondents (79%), whereas milk recording and dairy producer organizations were viewed as a "very important" source of information by 36% of respondents. Other producers (46%) and magazines or newspapers (51%) were commonly viewed as an "important" source of information. Online search engines were commonly used by respondents (94%). Social media was viewed as less important, and had mixed levels of use. YouTube (70%), Facebook (63%), and Twitter (18%) were the most commonly used social media platforms. Eighty percent of Twitter users reported using the platform to interact with and obtain or share information about herd health management online, which was the highest reported interactivy regarding herd health among all social media platforms. This exploratory study offers insight into the communication preferences of Canadian dairy producers and can be used to facilitate future communication strategies aimed at engaging rural farming audiences across Canada.

Transition Pathways Toward the Prudent Use of Antimicrobials: The Case of Free-Range Broiler Farmers in France

Reducing antimicrobial use (AMU) on farms is key for controlling the rise of resistant bacteria that have the potential capacity to infect humans via direct animal contact or via the food chain or the environment. To reduce AMU, antimicrobials must be used in a prudent and rational manner. Extensive efforts have been made recently to identify the cognitive and behavioral barriers to the appropriate use of antimicrobials by various livestock sector stakeholders. However, most studies carried out thus far have only partly captured the dynamic and systemic dimension of the processes involved in changes of practices related to AMU on farms. To shed light on the transition pathways implemented to reduce AMU, a qualitative study was conducted in France based on 28 semi-structured interviews with farmers, technicians and veterinarians from the free-range broiler production sector. Based on the thematic analysis of verbatims, we identified technical improvements which are key contributors to reduced AMU. We also highlighted some gaps in knowledge regarding AMU and antimicrobial resistance. We found that, rather than individual motivations alone, the extent to which farmers are embedded in collective organizations is decisive for changes in practices, and downstream operators (distributors and slaughterers) play a key role in the beginning of AMU transition pathways. As a result, we show that change in AMU requires a global rethinking of the overall socio-technical system rather than modifications of a single element in a farming system. Our results also highlight that transition pathways toward reduced AMU cannot just rely on trigger events, but also involves medium or long-term processes, with actors' experiences and practices being modified on an incremental basis over time. Our study sheds light on the need for multi and trans-disciplinary research involving the social sciences to analyze interactions between stakeholders and the collective actions implemented to tackle the challenge of AMU reduction.

Antimicrobial use practices and opinions of beef farmers in England and Wales

BACKGROUND

Limited research exists on antimicrobial use practices of beef farmers. This study aimed to investigate antimicrobial practices and perceptions of beef farmers in England and Wales, and identify drivers of higher antimicrobial use for treatment of bovine pneumonia.

METHODS

A survey was sent out in 2017 to beef farmers in England and Wales who supply to two abattoirs. Descriptive statistics were used to summarise the data. A logistic regression model was built to determine factors associated with treating greater than 5 per cent of the predominant group in the herd with antimicrobials for pneumonia.

RESULTS

There were a total of 171 useable responses. Most farmers reported using antimicrobials in less than 5 per cent of their herd for the treatment of common diseases. Most farmers (90 per cent) reported that they understood what antimicrobial resistance means, but only 55 per cent were aware of critically important antimicrobials and 9 per cent could name at least one critically important antimicrobial. Having a calf-rearing enterprise and not considering Johne's disease when buying in cattle were associated with using antimicrobials to treat pneumonia in greater than 5 per cent of the predominant group in the herd.

CONCLUSION

Self-reported antimicrobial use appears to be low in beef farms. However, some gaps in understanding aspects of antimicrobial stewardship by farmers were identified.

Point-of-care tests for bovine clinical mastitis: what do we have and what do we need?

Mastitis, inflammation of the bovine mammary gland, is generally caused by intramammary infection with bacteria, and antimicrobials have long been a corner stone of mastitis control. As societal concern about antimicrobial use in animal agriculture grows, there is pressure to reduce antimicrobial use in dairy farming. Point-of-care tests for on-farm use are increasingly available as tools to support this. In this Research Reflection, we consider available culture-dependent and culture-independent tests in the context of ASSURED criteria for low-resource settings, including convenience criteria, scientific criteria and societal criteria that can be used to evaluate test performance. As tests become more sophisticated and sensitive, we may be generating more data than we need. Special attention is given to the relationship between test outcomes and treatment decisions, including issues of diagnostic refinement, antimicrobial susceptibility testing, and detection of viable organisms. In addition, we explore the role of technology, big data and people in improved performance and uptake of point-of-care tests, recognising that societal barriers may limit uptake of available or future tests. Finally, we propose that the 3Rs of reduction, refinement and replacement, which have been used in an animal welfare context for many years, could be applied to antimicrobial use for mastitis control on dairy farms.

Addressing Individual Values to Impact Prudent Antimicrobial Prescribing in Animal Agriculture

Antimicrobial resistance is a growing public health threat driven by antimicrobial use—both judicious and injudicious—in people and animals. In animal agriculture, antimicrobials are used to treat, control, and prevent disease in herds of animals. While such use generally occurs under the broad supervision of a veterinarian, individual animals are often treated by farm owners or managers. The decision to administer antimicrobials is therefore influenced not only by the clinical situation but also by the motivations and priorities of different individual actors. Many studies have examined the drivers of external forces such as costs, workload and time constraints, or social pressures on antimicrobial use by veterinarians and producers, but none have explored the role of individually held values in influencing decision-making related to antimicrobial use. Values are deeply held normative orientations that guide the formation of attitudes and behaviors across multiple contexts. Values have been shown to be strongly tied to perceptions of and attitudes toward polarizing topics such as climate change, and preliminary evidence suggests that values are also associated with attitudes to antimicrobial resistance and stewardship. In this article, we draw on lessons learned in other fields (human health care, climate change science) to explore how values could be tied to the extrinsic and intrinsic factors that drive antimicrobial use and prescribing in animal agriculture. We also provide suggestions for ways to build a bridge between the veterinary and social sciences and incorporate values into future research aimed at promoting antimicrobial stewardship in animal agriculture.

Antimicrobial Resistance in Humans and Animals: Rapid Review of Psychological and Behavioral Determinants

A rapid review of current evidence examining psychological issues regarding the use of antibiotics and antimicrobials and resistance to these in both human and animal populations was conducted. Specific areas of interest were studies examining psychological determinants of AMR and interventions which attempt to change behavior with regard to AMR in the general population; animals; and fish, in particular. Although there is some evidence of the effectiveness of behavior change in general human populations, there is limited evidence in farmed animals, with a particular dearth in fish farming. We conclude there is an urgent need for more psychological research to identify major barriers and facilitators to change and evaluate the effectiveness of theory-based interventions aimed at reducing AM use in food production animals, including the promotion of alternatives to AMs, such as vaccination.

Antibiotics use versus profitability on sow farms in the Netherlands

In 2009, the Dutch government provided policy objectives (i.e., targets) for a reduction in veterinary antibiotics use of -20 % in 2011, -50 % in 2013 and -70 % in 2015 relative to the use in 2009. The relationship between antibiotics use and performance of Dutch sow farms during this policy reform was analysed using the Farm Accountancy Data Network database comprising cross-sectional farm data from 2004 to 2016. The results show that there is a significant downward trend in antibiotics use of 57 %. Panel data analysis (n = 74 sow farms) revealed that the reduction in antibiotic use did not lead to negative effects on technical or economic farm results. A follow-up survey was conducted on measures taken to improve animal health, which made the reduction in antibiotic use feasible. Of the 79 sow farmers approached, 55 participated in this survey. Sow farmers used a variety of relatively easy and affordable measures, such as more attention to hygiene, use of pain killers and anti-inflammatory agents, or applied more preventive vaccinations. Multivariable linear regression models showed that the intention, perceived risk and uncertainty, and perceived capability (to keep or get the use of antibiotics under the target value) were the most important predictors for antibiotics use from 2014 to 2016. Sow farmers who used more antibiotics were more concerned that low antibiotics use compromises their farm results, perceived more risk and uncertainty, and thought to a lesser extent that they have enough knowledge and time. These results indicate that providing these farmers with knowledge and information on management practices to reduce the use of antibiotics may be helpful. Thereby, it would be useful to focus on continuous involvement of the veterinarian and possibly the feed supplier, preferably by means of individual advice, as the results showed that individual advice was the preferred way to gather knowledge for the interviewed sow farmers and the veterinarian appeared to be the most important source of information to the interviewed sow farmers, followed by the feed supplier. In summary, the study shows that decrease in antibiotics use can be quite successful without compromising on the economic or technical performance, and moreover taking into account farmers' attitudes, perceptions and preferences can be helpful to get a better understanding of farmers' decision making and is useful for the design of tailor-made interventions.

The drivers of antibiotic use and misuse: the development and investigation of a theory driven community measure

Background

Antimicrobial resistance is a global public health concern, with extensive associated health and economic implications. Actions to slow and contain the development of resistance are imperative. Despite the fact that overuse and misuse of antibiotics are highlighted as major contributing factors to this resistance, no sufficiently validated measures aiming to investigate the drivers behind consumer behaviour amongst the general population are available. The objective of this study was to develop and investigate the psychometric properties of an original, novel and multiple-item questionnaire, informed by the Theory of Planned Behaviour, to measure factors contributing to self-reported antibiotic use within the community.

Method

A three-phase process was employed, including literature review and item generation; expert panel review; and pre-test. Investigation of the questionnaire was subsequently conducted through a cross-sectional, anonymous survey. Orthogonal principal analysis with varimax rotation, cronbach alpha and linear mixed-effects modelling analyses were conducted. A 60 item questionnaire was produced encompassing demographics, social desirability, three constructs of the Theory of Planned Behaviour including: attitudes and beliefs; subjective norm; perceived behavioural control; behaviour; and a covariate – knowledge.

Results

Three hundred seventy-three participants completed the survey. Eighty participants (21%) were excluded due to social desirability concerns, with data from the remaining 293 participants analysed. Results showed modest but acceptable levels of internal reliability, with high inter-item correlations within each construct. All four variables and the outcome variable of antibiotic use behaviour comprised four items with the exception of social norms, for which there were two items, producing a final 18 item questionnaire. Perceived behavioural control, social norms, the interaction between attitudes and beliefs and knowledge, and the presence of a healthcare worker in the family were all significant predictors of antibiotic use behaviour. All other predictors tested produced a nonsignificant relationship with the outcome variable of self-reported antibiotic use.

Conclusion

This study successfully developed and validated a novel tool which assesses factors influencing community antibiotic use and misuse. The questionnaire can be used to guide appropriate intervention strategies to reduce antibiotic misuse in the general population. Future research is required to assess the extent to which this tool can guide community-based intervention strategies.

Understanding the effect of producers' attitudes, perceived norms, and perceived behavioral control on intentions to use antimicrobials prudently on New York dairy farms

Understanding farmers' behavior, motivations, and perceptions toward antimicrobial use can influence how veterinarians translate research into practice and guide effective ways of implementing protocols. A multidisciplinary team investigated behavioral tendencies of New York dairy farmers toward antimicrobial use by administering a survey modeled with the reasoned action approach. This approach is a framework from social psychology containing the constructs attitude, perceived norms, and perceived behavioral control, and is used in combination with structural equation modeling to determine what drives intentions. Multiple indicators and multiple causes (MIMIC) models were then used to determine the effects of beliefs on their underlying constructs. The objective of the study was to provide direct and indirect measures of the constructs using survey data to determine importance of and associations with intention to use antimicrobials prudently. The structural equation model indicated that perceived behavioral control explained intention. Thus, farmers who feel capable of prudent use expressed positive intentions. Attitude and perception of others also had influence to a lesser extent. MIMIC models showed that the most important attributes of instrumental attitude were increasing profitability, decreasing risk of residues, and increasing herd health. Contributing attributes of affective attitude were job satisfaction, decreasing resistance, and increasing milk production. For perceived norms, the attributes were opinions/approval of family and peers, veterinarians, and milk processors. Finally, for perceived behavioral control, attributes focused on saving money on labor and treatment, ability to fit into the daily routine, and effectiveness with veterinary guidance. In conclusion, the best approach for adoption of practices might be presentation of examples of successful strategies by other producers, particularly in peer groups. In addition, veterinarians should provide the tools and guidance needed to produce economic gain, reduction of risks associated with residues and resistance, and positive experiences when using the tactics.

Immunomodulatory effect of thymopentin on lymphocytes from supramammary lymph nodes of dairy cows

Previous study showed that injection of thymopentin (TP 5) in the area of supramammary lymph nodes (SMLN) had therapeutic effect on the intramammary infection (IMI) in cows. This study was to explore the underlying mechanisms by investigating the immunomodulatory effect of TP 5 on SMLN lymphocytes. Lymphocyte proliferation, cell cycle distribution and cytokine mRNA expression were determined by MTT, FCM and RT-qPCR, respectively. Laser scanning confocal microscope (LSCM) was used to observe the binding between TP 5 and SMLN lymphocytes. Moreover, RNA-sequencing (RNA-seq) was performed to observe the difference between the lymphocytes with and without TP 5 treatment. The results showed that TP 5 significantly promoted lymphocyte proliferation, accelerated cell cycle progression, and enhanced mRNA expression of IL-17A and IL-17F. Laser scanning confocal microscopic analysis revealed the binding of TP 5 to the surface of SMLN lymphocytes. A total of 1094 genes were identified as differentially expressed genes (DEGs) using RNA-seq with 692 up- and 402 down-regulated genes. 48 significantly enriched GO terms were identified by RNA-seq. In KEGG analysis, 1/3 of DEGs were enriched in the immune system pathway, including IL-17 signaling pathway, cytokine-cytokine receptor interaction, Th1 and Th2 cell differentiation, T cell receptor signaling pathway, Th17 cell differentiation. Among them, IL-17 signaling pathway was the most prominent. This study suggested that the therapeutic benefit of TP 5 in the treatment of bovine mastitis might be attributed to its immunomodulatory activity in SMLN lymphocytes.

Shared Goals, Different Barriers: A Qualitative Study of UK Veterinarians' and Farmers' Beliefs About Antimicrobial Resistance and Stewardship

Although much research has investigated the drivers of inappropriate antimicrobial prescribing in human medicine, equivalent research in veterinary medicine is in its infancy. This qualitative study used a critical incident approach to explore farm veterinarians' (vets) and farmers' beliefs about antimicrobial use and antimicrobial stewardship. Semi-structured interviews were conducted with 13 vets and 12 farmers in the UK, who worked mostly with beef cattle, dairy cattle and sheep, but a minority also worked with pigs or poultry. An inductive thematic analysis was conducted to explore how vets and farmers understood their responsibilities toward stewardship and antimicrobial resistance (AMR) and to identify key similarities and differences between the professions. The analysis generated four themes: "A shared conflict between ideals and behaviour," "Barriers to stewardship: the vets' perspective," "Barriers to stewardship: the farmers' perspective," and "A shared ambivalence: ownership vs. other-blaming." Vets and farmers demonstrated good understanding of stewardship but their treatment decisions are not always aligned to stewardship principles. Various barriers to improving antimicrobial stewardship were discussed by vets and farmers, but they placed differing emphasis on specific barriers. Faced with these barriers and an awareness that antimicrobial usage is not always aligned to stewardship principles, vets and farmers expressed frustration and a sense of ambivalence toward stewardship, and also engaged in other-blaming for the problem of AMR. In conclusion, vets and farmers in this study seem motivated to be antimicrobial stewards but feel challenged by the day-to-day reality of their jobs; they experience ambivalence toward their responsibilities for AMR, which may negatively impact their motivation to always act as antimicrobial stewards. Successfully tackling AMR will require change at the individual-, group-, and societal-level. Future interventions to improve antimicrobial usage in livestock farming could be situated within a social ecological framework, where other-blaming between professions is seen as a result of the interplay between psychological and contextual factors. Other-blaming could be reduced using a social identity approach; a common ingroup identity could be created by encouraging vets and farmers to focus on their common goal, namely a shared desire to promote animal welfare through optimal antimicrobial stewardship.

Optimization of Antimicrobial Treatment to Minimize Resistance Selection

Optimization of antimicrobial treatment is a cornerstone in the fight against antimicrobial resistance. Various national and international authorities and professional veterinary and farming associations have released generic guidelines on prudent antimicrobial use in animals. However, these generic guidelines need to be translated into a set of animal species- and disease-specific practice recommendations. This article focuses on prevention of antimicrobial resistance and its complex relationship with treatment efficacy, highlighting key situations where the current antimicrobial drug products, treatment recommendations, and practices may be insufficient to minimize antimicrobial selection. The authors address this topic using a multidisciplinary approach involving microbiology, pharmacology, clinical medicine, and animal husbandry. In the first part of the article, we define four key targets for implementing the concept of optimal antimicrobial treatment in veterinary practice: (i) reduction of overall antimicrobial consumption, (ii) improved use of diagnostic testing, (iii) prudent use of second-line, critically important antimicrobials, and (iv) optimization of dosage regimens. In the second part, we provided practice recommendations for achieving these four targets, with reference to specific conditions that account for most antimicrobial use in pigs (intestinal and respiratory disease), cattle (respiratory disease and mastitis), dogs and cats (skin, intestinal, genitourinary, and respiratory disease), and horses (upper respiratory disease, neonatal foal care, and surgical infections). Lastly, we present perspectives on the education and research needs for improving antimicrobial use in the future.

A randomized controlled trial to evaluate performance of pigs raised in antibiotic-free or conventional production systems following challenge with porcine reproductive and respiratory syndrome virus

The trial objective was to compare the performance and animal health parameters of pigs raised according to one of 3 antibiotic (AB) protocols: standard AB medication consisting of mass treatment on days 4 and 21 and judicious AB therapy given therapeutically thereafter as group medication in water and feed or by individual injection (group T1, N = 702); modified AB medication identical to group T1 but with mass treatment only on day 4 and without subsequent therapeutic feed medication (group T2, N = 675); or an antibiotic-free (ABF) regimen (group T3, N = 702). All pigs were vaccinated with a modified-live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine 3 days after weaning. Using a seeder pig model to mimic endemic field infection dynamics, pigs were contact-challenged with virulent PRRSV lineage 1 strain 174 four weeks after vaccination. At finishing, average daily gain (ADG) and mean feed conversion ratio (FCR) were significantly better (p ≤ 0.05) for the T1 and T2 groups compared to the T3 group. There were no significant differences in post-weaning ADG and FCR between the T1 and T2 groups. Mortality and removals significantly favored (p ≤0.05) the T1 and T2 groups (20.94% and 24.89%, respectively) versus the T3 group (57.98%). Net revenue per pig was $105.43, $98.79, and $33.81 for the T1, T2 and T3 groups, respectively. Under the conditions of this study, these results indicate that in a PRRSV-endemic setting involving bacterial co-infections, an ABF production strategy may leave pigs at considerable risk of exposure to severe clinical disease and that judicious use of antibiotics can significantly improve animal health.