Drivers of Antimicrobial Use Practices among Tennessee Dairy Cattle Producers

Associations of the Swiss national reporting system's antimicrobial use data and management practices in dairy cows on tiestall farms

Antimicrobial use (AMU) in Switzerland is above target and requires reduction, especially in dairy cattle. Measuring AMU is pivotal to identifying starting points for AMU reduction, and so are studies investigating its potential drivers in dairy farms worldwide. However, although AMU in dairy farms is high, studies estimating AMU specifically in tiestall farms are scarce. Tiestalls are a common housing system and their prevalence among dairy farms accounts to approximatively 73%, 41%, and 40% in Canada, the United States, and Switzerland, respectively. The objectives of this cross-sectional, retrospective observational study were to estimate AMU using the newly established Swiss national reporting system for AMU in livestock and to identify associated factors on Swiss tiestall dairy farms. We calculated the treatment incidence (TI) by using the European Medicines Agency methodology and their defined daily dose (DDD) and defined course dose (DCD) standards. Data on factors potentially associated with AMU were obtained through personal interviews with farm managers on 221 farms. Retrospectively, during a 1-year period, data on a total of 7,619 treatments were extracted from the national database. Associations between management factors and TI were analyzed using a generalized linear model with gamma distribution. The mean (± SD) overall TI was 5.46 DDD/cow-year (± 4.10 DDD/cow-year). Intramammary treatment during lactation accounted for highest TI (3.24 ± 3.16 DDD/cow-year), whereas dry-cow therapy accounted for lowest TI (0.44 ± 0.49 DCD/cow-year). We found that 5 of the investigated management factors were significantly associated with TI. Organic production (estimate = -2.16; 95% CI = -3.62 to -0.70) and herd size (estimate = -0.81; 95% CI = -1.23 to -0.39) were negatively associated with TI. Specific cow breeds (Brown Swiss estimate = 1.56; 95% CI = 0.45-2.68) and Holstein Friesian (estimate = 1.42; 95% CI = 0.03-2.82; reference: other breeds) and the use of hygienic powders on the lying area (estimate = 1.10; 95% CI = 0.04-2.17) were positively associated with TI. Overall, the Swiss national reporting system is a valuable tool for AMU estimation. Several herd characteristics and management factors were associated with AMU in tiestall farms. Further studies focusing on factors associated with AMU and which are amenable to intervention will help improve stewardship programs and subsequently reduce AMU in dairy cows.

Knowledge, Attitude, and Practice of Thai Dairy Farmers on the Use of Antibiotics

Antibiotics have been used regularly in dairy farms by veterinarians; however, they were also used occasionally by farmers without any veterinary prescriptions. Because knowledge, attitude, and practice are important for sustainable antibiotic use, the levels of these aspects among farmers and associated factors should be determined to improve antibiotic use in dairy farming. The study was carried out in 89 Thai dairy farmers, using a structured questionnaire. Data were analyzed using descriptive statistics. The questions were scored and the total scores were calculated for each aspect. Factors associated with knowledge, attitude, and practice scores were identified using the multivariate linear regression. The mean scores for knowledge, attitude, and practice were 62%, 86%, and 78%, respectively. Higher education, participation in a training related to antibiotic use, and being supervised by the Veterinary Teaching Hospital Nong Pho were associated with a higher knowledge score (p < 0.050). Farmers with less experience received a higher attitude score (p = 0.020). Acquiring antibiotic knowledge from other farmers was associated with a lower practice score (p = 0.005). A positive association was found between knowledge and attitude scores (p = 0.021) and practice and attitude score (p < 0.001). Due to the insufficient knowledge on antibiotic use, there is a need to fill the gap to ensure prudent antibiotic use by farmers. Recommendations including training farmers by veterinarian to perceive the prudent antibiotic uses, encouraging young generation with higher education to participate in dairy farming, providing antibiotic use protocols, and decreasing the availability of antibiotics should be implemented to limit overuse by farmers.

Assessment of Knowledge, Attitude and Practice (KAP) Regarding Antimicrobial Usage and Resistance Among Animal Health Professionals of East Wallaga Zone, Oromiya, Ethiopia

Background

Antimicrobial resistance (AMR) is one of the top global public health and economic threats. The use of antimicrobials (AMs) in animal production is a major contributor to the development of AMR globally. Animal health professionals (AHPs) play a key role in ensuring judicious use of AMs.

Objective

To assess the knowledge, attitude and practice (KAP) of antimicrobial usage (AMU) and AMR among healthcare professionals in Nekemte town, Leka Dulecha and Sibu Sire districts.

Methods

A cross-sectional study was conducted with 120 purposively chosen AHPs residing in the districts and the town. A semi-structured questionnaire consisting of 49 questions was used to ascertain the KAP. The chi-square test (X2) was used to analyze the association between the knowledge score and demographic profile of the study participants.

Results

In the study the overall knowledge of the participants was moderately appreciable, and all participants had positive attitudes toward AMR and appropriate usage. In terms of knowledge of antibiotic use, the majority (93.33%) of the participants correctly answered the statement that antibiotics can kill viruses. About 84.17% of the participants correctly knew that antibiotics killed or stopped the growth of both bad and good bacteria. The majority of the participants (74.17%) always or (25.83%) sometimes rely on usage of antibiotics without a doctor's prescription. It was shown that comparing respondents from Sibu Sire, Leka Dulecha and Nekemte town, the scores of knowledge of AMU were significantly (X2=14.13, p=0.007) different. Most animal healthcare professionals from the Sibu sire have a good knowledge of AMU, and contribute to AMR development.

Conclusion

The study revealed that there was moderate knowledge and positive attitude toward AMU and resistance. This warrants continuing capacity building programs for the professionals on AM usage and resistance, and development of field-friendly disease diagnosis and management tools is essential in the need to reduce AMR.

Understanding the role of veterinarians in antimicrobial stewardship on Canadian dairy farms: A mixed-methods study

The aim of this study was to describe the factors that influence dairy cattle veterinarians´ antimicrobial prescribing, their attitudes toward reducing antimicrobial use (AMU) in the dairy industry, awareness of antimicrobial resistance (AMR), and perceived barriers to improving antimicrobial stewardship (AMS) on Canadian dairy farms. We used quantitative and qualitative research methods to consider the complexity of the antimicrobial prescription decision-making process. We designed and distributed an online survey, followed by four online focus groups with practicing veterinarians. We used frequency tables and unconditional associations to analyze quantitative data, and thematic analysis to analyze qualitative data. In total, 107 participants from four Canadian provinces responded to the survey, and 26 veterinarians participated in the focus groups. Results from both studies were triangulated to draw our key findings. We found that 1) Veterinarians must weigh numerous intra-personal and contextual considerations that could be conflicting in their decision-making process for prescribing antimicrobials. 2) Although less experienced veterinarians showed greater awareness of AMR and motivation to improve AMS than more experienced veterinarians, they also reported feeling more pressure to adapt their prescribing practices to farmers' wishes than more experienced veterinarians. 3) Some veterinarians experienced conflict between prescribing antimicrobials to maintain animal health, productivity, and welfare, and AMS, which could result in blaming others for inappropriate antimicrobial use and reducing the opportunity to critically review their own prescribing practices. 4) There were strategies and barriers in common between veterinarians and farmers such as collaborative reviews of disease treatment protocols and improving preventive medicine on dairy farms. 5) The main barriers to reducing AMU on dairy farms reported by veterinarians were concerns about animal welfare and AMU on dairy farms without consultation with the veterinarian. Our results can inform the development of AMS programs in the Canadian dairy industry.

Livestock producers' knowledge, attitude, and behavior (KAB) regarding antimicrobial use in Ethiopia

Introduction

Inappropriate antimicrobial use (AMU) in livestock production is an important aspect of the global burden of antimicrobial resistance (AMR). In Ethiopia, a low-income country with a large and increasing livestock population, AMU in food animals is not properly regulated. Hence, farmers are fully free to use antimicrobials to their (perceived) benefit. Therefore, understanding farmers' mindsets is important to improve antimicrobial stewardship in the livestock sector.

Methods

This cross-sectional study was conducted to assess livestock disease management practices and knowledge, attitude, and behavior (KAB) among livestock producers regarding AMU, residues, and resistance, as well as factors potentially explaining differences in KAB. We determined the KAB of livestock owners of three selected districts of central and western Ethiopia (n = 457), using a pretested questionnaire administered through face-to-face interviews. Logistic regression was used to evaluate the association between potential explanatory variables and the KAB scores of the respondents.

Results

The results showed that 44% of the farmers used antimicrobials in the past few years, where antibiotics (21%) and trypanocides (11%) were most widely used to manage livestock diseases. Furthermore, most farmers showed poor knowledge about AMU, residues, and AMR (94%) and unfavorable attitudes (<50% correct answers) toward contributing factors for AMR (97%). On the contrary, 80% of the respondents had overall good behavior scores (≥50% correct answers) related to AMU. Multivariate analysis results showed that having good knowledge, keeping ≥2 animal species, and the occurrence of ≥4 livestock diseases on the farm in a year were strong predictors of bad behavior scores (p < 0.05). The findings of the current investigation also revealed that the incidence of livestock diseases on the farm and a higher level of formal education significantly contributed to better knowledge and desirable attitudes but bad AMU behavior.

Conclusion

A low level of awareness about and undesirable attitudes toward AMU and AMR could potentially affect farmers' behavior toward judicious AMU, thus requiring awareness creation efforts on livestock disease management practices.

Barriers and facilitators to implementing a new regulation restricting antimicrobial use in dairy production in Québec, Canada: A qualitative study

With the emergence of antimicrobial resistance (AMR), many countries are implementing restrictive regulations to reduce antimicrobial use (AMU) in animal production. Although these measures are effective at the national level, their implementation may generate challenges for producers and veterinarians. The objective of this study was to explore the barriers and facilitators of implementing a new regulation restricting the use of antimicrobials of very high importance for human health in the dairy production sector in the province of Québec, Canada. Individual interviews were conducted with fifteen veterinarians and twenty-seven dairy producers. Thematic analysis was performed based on the COM-B model of behavior change (capability-opportunity-motivation-behavior). Our results indicated that the lack of availability of alternative treatments, the long delays related to diagnostic tests and the fear of economic consequences were major barriers to the implementation of the regulation. A small number of producers also perceived that the regulation negatively impacted the health and wellbeing of their animals. Additionally, participants acknowledged the importance of early education and training to better understand the purpose of the regulation and increase its acceptability. Lastly, most participants reported that they had not only reduced their use of antimicrobials of very high importance for human health following the regulation, but they had also increased preventive practices on their farm. This study reveals that the implementation of restrictive regulations to reduce AMU in animal production can lead to multiple challenges in practice. Our results highlight the need for better communication and training of producers and veterinarians before and during the implementation of similar regulations in the future and underline the importance of measuring the direct and indirect impacts of those regulations on productivity and on animal health and wellbeing.

Extended-Spectrum Beta-Lactamases Producing Enterobacteriaceae in the USA Dairy Cattle Farms and Implications for Public Health

Antimicrobial resistance (AMR) is one of the top global health threats of the 21th century. Recent studies are increasingly reporting the rise in extended-spectrum beta-lactamases producing Enterobacteriaceae (ESBLs-Ent) in dairy cattle and humans in the USA. The causes of the increased prevalence of ESBLs-Ent infections in humans and commensal ESBLs-Ent in dairy cattle farms are mostly unknown. However, the extensive use of beta-lactam antibiotics, especially third-generation cephalosporins (3GCs) in dairy farms and human health, can be implicated as a major driver for the rise in ESBLs-Ent. The rise in ESBLs-Ent, particularly ESBLs-Escherichia coli and ESBLs-Klebsiella species in the USA dairy cattle is not only an animal health issue but also a serious public health concern. The ESBLs-E. coli and -Klebsiella spp. can be transmitted to humans through direct contact with carrier animals or indirectly through the food chain or via the environment. The USA Centers for Disease Control and Prevention reports also showed continuous increase in community-associated human infections caused by ESBLs-Ent. Some studies attributed the elevated prevalence of ESBLs-Ent infections in humans to the frequent use of 3GCs in dairy farms. However, the status of ESBLs-Ent in dairy cattle and their contribution to human infections caused by ESBLs-producing enteric bacteria in the USA is the subject of further study. The aims of this review are to give in-depth insights into the status of ESBL-Ent in the USA dairy farms and its implication for public health and to highlight some critical research gaps that need to be addressed.

Emotive Themes from Tennessee Cattle Producers Regarding Responsible Antibiotic Use

To improve judicious antimicrobial use (AMU) in food animals in the United States, all feed additives that were medically important antimicrobials were moved from over the counter to Veterinary Feed Directive in 2017. This action required a change in behavior of producers’ AMU practices. Because emotions are important aspects of behavior, several behavioral interventions have targeted people’s emotions as means of effecting change. Hence, understanding and incorporating the emotional experiences of producers towards current AMU practices can be a starting point to making future behavioral changes that could reduce the emergence of antimicrobial resistance challenge. Between June 2017 and March 2018, seven focus group meetings of Tennessee (TN) beef and dairy cattle producers were conducted to evaluate producers’ emotional views regarding responsible AMU in TN cattle. Sixty-two TN cattle producers participated and emotively expressed the following: (1) deep connections to animals in ways that improve animal and public health; (2) pride in their quality of products; (3) distress that consumers misconceive their AMU practices as indiscriminate; and (4) recommended that producers be more transparent about their AMU practices and the public improve their awareness for detecting marketers’ deceptive product labels that take advantage of public ignorance. Knowledge of these producers’ emotions would help educators target more successful behavioral change campaigns, improving stewardship in AMU practices among producers.

Wisconsin dairy farm worker perceptions and practices related to antibiotic use, resistance, and infection prevention using a systems engineering framework

We studied farmworker practices and beliefs potentially contributing to transmission of bacteria and their associated antibiotic resistance genes (ARGs) among animals and farm workers to identify potential behavioral interventions to reduce the risk of bacterial transmission. Ten focus groups were conducted on eight Wisconsin dairy farms to assess potentially high-risk practices and farmworker knowledge and experiences with antibiotic use and resistance using the Systems Engineering in Patient Safety (SEIPS) framework. Farmworkers were asked to describe common on-farm tasks and the policies guiding these practices. We found workers demonstrated knowledge of the role of antibiotic stewardship in preventing the spread of ARGs. Worker knowledge of various forms of personal protective equipment was higher for workers who commonly reported glove-use. Additionally, workers knowledge regarding the importance of reducing ARG transmission varied but was higher than we had hypothesized. Programs to reduce ARG spread on dairy farms should focus on proper hand hygiene and personal protective equipment use at the level of knowledge, beliefs, and practices.

Educational interventions to address misconceptions about antibiotic residues in milk can alter consumer perceptions and may affect purchasing habits

The industrialization of the agri-food industry and resultant decrease in the number of people employed on farms has contributed to a knowledge gap among consumers about food production processes. A commonly reported concern of dairy consumers is the use of antibiotics in dairy animals, even though these drugs are an important tool for promoting animal health and welfare and food safety. The extent to which consumers are aware of antibiotic residue avoidance practices in dairy production is unknown, and it is unclear whether acquisition of such knowledge could affect purchasing behavior and perceptions of dairy farming. The objectives of this study were to assess consumers' perceptions about the quality and production of dairy products in the United States and determine whether educational materials on processes that limit the occurrence of antibiotic residues in milk can change consumers' perceptions of dairy products and purchasing behaviors. We surveyed 804 consumers and assigned them to 1 of 3 interventions: (1) a control arm (reading the content of the Dairy page of the USDA's myplate.gov website); (2) an educational brochure on the processes that prevent antibiotic residues in milk; and (3) a video on the same processes. We found that a majority (86.1%) of participants believe that the quality of dairy products in the United States is high, although many had concerns about the treatment of dairy animals and chemicals (pesticides, antibiotics, hormones) in dairy products. Compared with the control intervention, the brochure was associated with a significant decrease in the level of concern consumers had about chemicals in their milk [-0.20 points on a Likert scale, 95% confidence interval (CI), -0.32 to -0.08] and a significantly increased comfort in purchasing conventional dairy products (odds ratio 2.43, 95% CI, 1.62 to 3.66). The video was associated with even stronger effects: a 0.29-unit decrease in the level of concern about chemicals in milk (95% CI, -0.42 to -0.016) and 2.94 times greater odds of purchasing conventional dairy products (95%, CI 1.92 to 4.49). Although consumer food decision making is complex and driven by multiple factors, it appears that education about the processes that promote food safety can reassure consumers about their concerns and potentially affect purchasing habits.

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.

2019 Survey of Antimicrobial Drug Use and Stewardship Practices in Adult Cows on California Dairies: Post Senate Bill 27

Antimicrobial resistance (AMR) is a global issue for both human and animal health. Antimicrobial drug (AMD) use in animals can contribute to the emergence of AMR. In January 2018, California (CA) implemented legislation (Senate Bill 27; SB 27) requiring veterinary prescriptions for medically important AMD use in food animals. The objective of our survey was to characterize AMD use, health management, and AMD stewardship practices of adult cows on CA dairies since the implementation of SB 27. In 2019, we mailed a questionnaire to 1282 California dairies. We received a total of 131 (10.2%) survey responses from 19 counties in CA. Our results showed that 45.6% of respondents included a veterinarian in their decision on which injectable AMD to purchase. Additionally, 48.8% of dairy producers included a veterinarian in their decision on which AMDs were used to treat sick cows. The majority (96.8%) of dairy producers were aware that all uses of medically important AMDs require a prescription. Approximately 49% of respondents agreed or strongly agreed that AMD use in livestock does not cause problems in humans. The survey documents antimicrobial use and stewardship practices in CA's dairy industry and focus areas for future research and education.

2018 Survey of antimicrobial drug use and stewardship practices in adult cows on California dairies: post-Senate Bill 27

BACKGROUND

A survey of California (CA) dairies was performed in spring 2018 to characterize antimicrobial stewardship practices, antimicrobial drug (AMD) use, and health management of adult cows on CA dairies since the implementation of the Veterinary Feed Directive (VFD) and the CA Senate Bill 27 (SB 27). Effective January 1, 2017, the U.S. Food and Drug Administration (FDA) implemented regulatory changes requiring veterinary oversight for therapeutic uses of medically-important antimicrobial drugs (MIADs) administered in feed (VFD) and water (veterinary prescription). Similarly, effective January 1, 2018, the CA legislature enacted California Food and Agricultural Code (FAC) 14400-14408, formerly known as Senate Bill 27 (SB 27) requiring veterinary prescriptions for all other dosage forms of MIADs.

METHODS

The questionnaire consisted of 43 questions partitioned into three sections to assess herd information, management practices, and AMD use and perspectives. The questionnaire was mailed to 1,282 grade A licensed dairies in CA and 149 responses (11.6%) were collected from 19 counties across the three defined regions of CA: Northern CA (NCA), Northern San Joaquin Valley (NSJV), and Greater Southern CA (GSCA).

RESULTS

Most dairies reported treating all dry cows with intramammary AMD and/or teat sealant at the end of a lactation (87.2%). In 92.3% of dairies, producers relied on the veterinarian for information about AMD used to treat cows. Treatment duration for cows treated with AMD was based on the drug manufacturer's label and veterinarian's instructions in most dairies (98.6%). Most respondents to the survey confirmed having a valid veterinarian-client-patient-relationship (VCPR) for their dairies (91.7%), participated in animal welfare audit programs (81.8%) and dairy quality assurance programs (52.9%). Approximately 98.6% respondents were aware that all uses of MIADs in livestock required a veterinary feed directive (VFD) or prescription and are no longer sold over-the-counter (OTC) in CA since January 1, 2018. Multiple factor analysis (MFA) was performed and identified seven components composed of 21 variables (questions) that explained 99.7% of the total variance in the data. Hierarchical cluster analysis on the principal coordinates of the MFA based on conventional dairy survey responses identified two clusters characterized as large conventional dairies (median herd size: 1,265 cows) and mid-sized conventional dairies (median herd size: 715 cows) mostly in GSCA and NSJV. The organic dairies grouped into a single cluster of median herd size of 325 cows mostly in NCA.

CONCLUSIONS

The survey results contribute to the knowledge of AMD use and antimicrobial stewardship practices on CA dairies since the implementation of the SB 27 and VFD laws and provide useful information for future evaluation of resistance-related risk in adult cows.

2018 Survey of factors associated with antimicrobial drug use and stewardship practices in adult cows on conventional California dairies: immediate post-Senate Bill 27 impact

BACKGROUND

Antimicrobial drugs (AMD) are critical for the treatment, control, and prevention of diseases in humans and food-animals. Good AMD stewardship practices and judicious use of AMD are beneficial to the preservation of animal and human health from antimicrobial resistance threat. This study reports on changes in AMD use and stewardship practices on California (CA) dairies, following the implementation of CA Senate Bill 27 (SB 27; codified as Food and Agricultural Code, FAC 14400-14408; here onward referred to as SB 27), by modeling the associations between management practices on CA conventional dairies and seven outcome variables relating to AMD use and stewardship practices following SB 27.

METHODS

A survey questionnaire was mailed to 1,282 grade A licensed dairies in CA in spring of 2018. Responses from 132 conventional dairies from 16 counties were included for analyses. Multivariate logistic regression models were specified to explore the associations between survey factors and six outcome variables: producers' familiarity with the Food and Drug Administration's (FDA), Silver Spring, WA, USA medically important antimicrobial drugs (MIAD) term; change in over-the-counter (OTC) AMD use; initiation or increased use of alternatives to AMD; changes to prevent disease outbreaks; changes in AMD costs; and better animal health post SB 27. We employed machine learning classification models to determine which of the survey factors were the most important predictors of good-excellent AMD stewardship practices of CA conventional dairy producers.

RESULTS

Having a valid veterinary-client-patient-relationship, involving a veterinarian in training employees on treatment protocols and decisions on AMDs used to treat sick cows, tracking milk and/or meat withdrawal intervals for treated cows, and participating in dairy quality assurance programs were positively associated with producers' familiarity with MIADs. Use or increased use of alternatives to AMDs since 2018 was associated with decreased use of AMDs that were previously available OTC prior to SB 27. Important variables associated with good-excellent AMD stewardship knowledge by CA conventional dairy producers included having written or computerized animal health protocols, keeping a drug inventory log, awareness that use of MIADs required a prescription following implementation of SB 27, involving a veterinarian in AMD treatment duration determination, and using selective dry cow treatment.

CONCLUSIONS

Our study identified management factors associated with reported AMD use and antimicrobial stewardship practices on conventional dairies in CA within a year from implementation of SB 27. Producers will benefit from extension outreach efforts that incorporate the findings of this survey by further highlighting the significance of these management practices and encouraging those that are associated with judicious AMD use and stewardship practices on CA conventional dairies.

New York State dairy veterinarians' perceptions of antibiotic use and resistance: A qualitative interview study

Antimicrobial resistance (AMR) limits the ability to prevent and treat infection, making AMR one of the foremost threats to human and animal health. Animal agriculture's large use of antibiotics in food animals is an important factor in AMR. As such, policies to reduce antibiotic use and combat AMR in animal agriculture in the United States (US) have been in place or are developed. One key to the success of these policies in the US is understanding how a major stakeholder - veterinarians treating dairy cattle - perceive the scale of antibiotic use, the threat of AMR and the utility of antibiotic use policies. We interviewed 9 dairy veterinarians in New York State and conducted an iterative thematic analysis of their responses, through which five themes were identified: 1. veterinarians' views of the frequency and reasons for antibiotic misuse, 2. their ideas on reducing antibiotic use, 3. perceptions of AMR within the dairy industry, 4. view of organic farming and how it relates to animal welfare, and 5. the impact of consumers' beliefs on the dairy industry. Participants viewed antibiotic overuse as largely due to farmers' concern for the welfare of their cattle and desire to treat ailments swiftly. Interviewees believed that it was possible to reduce antibiotic use through regulation, such as the Veterinary Feed Directive and improved herd management activities, such as better colostrum management, culture-based mastitis treatment, and improved housing conditions. They did not view the dairy industry as a significant contributor to AMR, particularly when compared to the human medical industry. Interviewees also offered their (unsolicited) opinion on organic dairy farming in the US and expressed frustration with the limited treatment options available in organic dairy farming and how this dynamic may potentially compromise animal welfare. Finally, they commented on the impact of consumers' beliefs on the dairy industry, expressing frustration with how misinformation about the dairy industry has led to consumer driven changes. As consumer beliefs have an impact on the dairy industry, this influence could be leveraged to further decrease antibiotic use. These findings can help guide future efforts in veterinarian-client communication and the development and implementation of effective policies in New York State. These results also highlight the need for more quantitative research on antibiotic use in the dairy industry, as without this data it will be difficult to ascertain the true impact of policy interventions.

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.

Survey on Antimicrobial Drug Use Practices in California Preweaned Dairy Calves

The California (CA) dairy industry was surveyed in July 2017 to evaluate producers' knowledge and perceptions and antimicrobial drug (AMD) use in preweaned dairy calves following the implementation of the nationwide veterinary feed directive final rule (VFD) in January 2017 and prior to statewide implementation of CA Senate Bill (SB) 27 in January 2018. Together, these regulations require veterinary oversight for all uses of medically important antimicrobial drugs (MIADs) administered to livestock in CA. Survey questionnaire was mailed to 1,361 CA Grade A milk producing dairies and calf ranches across CA resulting in a 12% (169) response. Most respondents (83%) were aware of the VFD and SB 27 changes. Use of antibiotics was perceived as important (77%) in raising preweaned dairy calves and judicious use of antibiotics was ranked as the most important antimicrobial stewardship practice, amongst record keeping, observing withdrawal periods, having a valid Veterinarian-Client-Patient-Relationship (VCPR), and use of alternatives to antibiotics. Treating sick calves was the major indication for AMD use (90.5%); however, few producers reported use of antibiotics to control (12.7%) or prevent disease (11%). Neomycin sulfate, chlortetracycline, oxytetracycline and sulfamethazine were the most used AMD. The respondents reported a decreased use of AMD in milk (10%) and in solid feed (5%), and discontinuation of one or more AMDs used in milk (18.6%) or in solid feed (5%) post-VFD rule implementation in 2017. Most respondents reported keeping treatment records and the information recorded included date (82%), dose (44%) and route (15%) of AMD used. A few respondents reported they had initiated use of alternatives to AMDs, such as vitamins (32.6%), minerals (25.6%), herbal remedies (11.6%) and pathogen specific antibodies (7%), post-VFD. The limited changes noted in AMD use could be attributed to the short period between the implementation of the VFD and the time of the survey. Our study outcomes identified opportunities to improve AMD use practices, including record keeping and use of AMD alternatives, and provides a baseline for future evaluation of the impact of these regulatory changes, as well as guidance for the future recommendations on best practices to promote judicious AMD use.

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.

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.

Antimicrobial Resistance of Major Bacterial Pathogens from Dairy Cows with High Somatic Cell Count and Clinical Mastitis

Simple Summary

Mastitis is the most prevalent disease of dairy cattle that causes significant economic losses. Different agents cause mastitis which leads to increased somatic cell count (SCC) and low milk quality. Treating mastitis with antimicrobials is essential to reduce SCC and improve milk quality. Excessive use or misuse of antimicrobials in dairy farms leads to the development of antimicrobial resistant bacteria. The objectives of this study were (1) to isolate and identify the causative agent of mastitis and (2) determine antimicrobial resistance profiles of bacterial isolates. A total of 174 quarter milk samples from 151 cows with high SCC and clinical mastitis from 34 dairy farms in Tennessee, Kentucky, and Mississippi were collected. Bacterial causative agents were determined by bacteriological and biochemical tests. Antimicrobial resistance of bacterial isolates against 10 commonly used antimicrobials was tested. A total of 193 bacteria consisting of six bacterial species, which include Staphylococcus aureus, Streptococcus uberis, Streptococcus dysgalactiae, Escherichia coli, Klebsiella oxytoca and Klebsiella pneumoniae were isolated. Staphylococcus aureus was the predominant isolate. The proportion of resistant isolates was relatively higher in Gram-negatives than Gram-positives. Continuous antimicrobial resistance testing and identification of reservoirs of resistance traits in dairy farms are essential to implement proper mitigation measures.

Abstract

Mastitis is the most prevalent and economically important disease caused by different etiological agents, which leads to increased somatic cell count (SCC) and low milk quality. Treating mastitis cases with antimicrobials is essential to reduce SCC and improve milk quality. Non-prudent use of antimicrobials in dairy farms increased the development of antimicrobial resistant bacteria. This study’s objectives were (1) to isolate and identify etiological agents of mastitis and (2) to determine antimicrobial resistance profiles of bacterial isolates. A total of 174 quarter milk samples from 151 cows with high SCC and clinical mastitis from 34 dairy farms in Tennessee, Kentucky, and Mississippi were collected. Bacterial causative agents were determined by bacteriological and biochemical tests. The antimicrobial resistance of bacterial isolates against 10 commonly used antimicrobials was tested. A total of 193 bacteria consisting of six bacterial species, which include Staphylococcus aureus, Streptococcus uberis, Streptococcus dysgalactiae, Escherichia coli, Klebsiella oxytoca and Klebsiella pneumoniae were isolated. Staphylococcus aureus was the predominant isolate followed by Strep. spp., E. coli, and Klebsiella spp. Results of this study showed that Gram-negatives (E. coli and Klebsiella spp.) were more resistant than Gram-positives (Staph. aureus and Streptococcus spp.). Continuous antimicrobial resistance testing and identification of reservoirs of resistance traits in dairy farms are essential to implement proper mitigation measures.

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.

New York State dairy farmers' perceptions of antibiotic use and resistance: A qualitative interview study

Antibiotic resistance is a global problem affecting both human and animal health. Ensuring the strategic and effective use of antibiotics is paramount to combatting the emergence and spread of resistance. This study explored New York State (NYS) dairy farmers' perceptions regarding antibiotic use in dairy farming and antibiotic resistance. Dairy farmers' perceptions were assessed through semi-structured, in-person interviews. Twenty interviews with farm owners and/or managers of 15 conventional and five USDA certified organic dairy farms with 40 to 2,300 lactating cows were conducted. Thematic analysis was used to assess, compare and contrast transcripts for farmers' characterization of their beliefs, values, and concerns. Conventional dairy farmers had a low level of concern about the possible impacts of on-farm antibiotic resistance on human health and believed their antibiotic use was already judicious. Generally, they believed their cattle's health would suffer if antibiotic use were further curtailed. Conventional farmers expressed frustration over the possibility of more stringent governmental, milk cooperative, buyer, or marketer requirements for antibiotic use and associated animal welfare in the future. They attributed expanding regulations in part to misinformed consumer preferences, that farmers felt were influenced by the marketing of organic dairy products. Organic dairy farmers were generally more concerned about issues related to antibiotic resistance than conventional farmers. Both conventional and organic farmers placed emphasis on disease prevention through herd health management rather than treatment. In conclusion, the conventional NYS dairy farmers in this study were skeptical of the need for and benefits of reduced antibiotic use on their dairy farms. Interventions for farmers, delivered by a trusted source such as a veterinarian, that provide training about proper antibiotic use practices and information of possible financial benefits of refining antibiotic use may hold promise.

Perceptions of Tennessee cattle producers regarding the Veterinary Feed Directive

Since January 1, 2017, the United States Food and Drug Administration (FDA) has fully implemented the Veterinary Feed Directive (VFD) final rule aimed at facilitating the judicious use of medically important antimicrobials in food-producing animals. The objective of this study was to identify the common perceptions of Tennessee (TN) cattle producers regarding the VFD. We used a combination of focus groups and survey questionnaires to explore TN cattle producers' perceptions regarding the VFD. Preliminary findings from seven focus groups of 62 producers were used in the development of the questionnaire sent both online and in-print to rest of cattle producers in TN. The beef focus group participants perceived the VFD: to be a top-down policy; to have led to unregulated access to in-feed antimicrobials; a regulation that has limited the producers' ability to prevent disease and leading to economic losses; to negatively affect small producers; and to be affected by challenges related to prescription writing and disposal of un-used medicines. The dairy focus group participants perceived the VFD as unnecessary and burdensome, to have affected small producers, and introduced additional costs. Among the survey questionnaire respondents, 35 (15.4%) beef producers and 6 (13.6%) dairy producers respectively were not familiar at all with the VFD. Forty-eight (21.1%) beef producers and 11 (25%) dairy producers were slightly familiar with VFD. Gender was significantly associated (P = 0.02) with the beef producers' belief in the usefulness of the VFD. Similarly, for dairy producers, herd size was significantly associated (P = 0.002) with their perceptions regarding the usefulness of the VFD. The findings of this study could inform future VFD policy review processes. More awareness regarding the VFD and its benefits is needed among both beef and dairy producers in TN.