Stakeholders' perceptions of the challenges to improving calf health and reducing antimicrobial use in Swiss veal production

Invited review: Qualitative research in dairy science-A narrative review

The use of qualitative research in dairy science has increased considerably in recent years, providing the opportunity to inform research and practice. This review aims to enhance the accessibility of qualitative research among a range of audiences and specifically: (1) provide an overview of what qualitative research is and the value it can bring to scientific inquiries in the dairy context, (2) illustrate the emergence of qualitative dairy science research in the past 15 to 20 years, (3) outline the role of the researcher and key philosophical assumptions underlying qualitative research, (4) describe qualitative research approaches and methods used in dairy science research, and (5) highlight key aspects of qualitative inquiry used to ensure research trustworthiness. Qualitative approaches in dairy science enable researchers to understand myriad topics including stakeholder relationships, decision-making, and behaviors regarding dairy cattle management, animal welfare, and disease prevention and control measures. Approaches that were used often for qualitative data collection were individual interviews and focus groups, and variations of thematic analysis were common analytical frameworks. To assess public values, attitudes, and perceptions, mixed methods questionnaires that combined quantitative data with qualitative data from open-ended questions were used regularly. Although still used infrequently, action research and participatory approaches have the potential to bridge the research-implementation gap by facilitating group-based learning and on-farm changes. Some publications described the philosophical assumptions inherent to qualitative research, and many authors included reflexivity and positionality statements. Although a comprehensive description of strategies to meet trustworthiness criteria for qualitative research was uncommon, many publications mentioned certain aspects of trustworthiness, such as member checking, researcher triangulation, and the recording of reflexive notes. Qualitative research has been used to deepen our understanding of phenomena relevant to the dairy sector and has opened the door for a broad array of new opportunities. In addition to having merit on its own, qualitative research can guide, inform, and expand on quantitative research, and an understanding of the core pillars of qualitative research can foster interdisciplinary collaborations.

Antimicrobial resistance and its relationship with antimicrobial use on Austrian dairy farms

The aim of this study was to investigate the prevalence of ESBL/AmpC-producing E. coli and the resistance pattern of commensal E. coli, as well as the link between the use of antibiotics (AMU) and the occurrence of resistance in E. coli on Austrian dairy farms. AMU data from 51 farms were collected over a one-year period in 2020. Fecal samples were collected from cows, pre-weaned and weaned calves in 2020 and 2022. Samples were then analyzed using non-selective and selective agar plates, E. coli isolates were confirmed by MALDI-TOF analysis. Broth microdilution was used for antimicrobial susceptibility testing. The AMU of each farm was quantified as the number of Defined Daily Doses (nDDDvet) and Defined Course Doses (nDCDvet) per cow and year. Cephalosporins (mean 1.049; median 0.732 DDDvet/cow/year) and penicillins (mean 0.667; median 0.383 DDDvet/cow/year) were the most frequently used antibiotics on these farms, followed by tetracyclines (mean 0.275; median 0.084 DDDvet/cow/year). In 2020, 26.8% of the E. coli isolated were resistant to at least one antibiotic class and 17.7% of the isolates were classified as multidrug resistant (≥3 antibiotic classes). Out of 198 E. coli isolates, 7.6% were identified as extended-spectrum/AmpC beta-lactamase (ESBL/AmpC) producing E. coli. In 2022, 33.7% of E. coli isolates showed resistance to at least one antibiotic and 20.0% of isolates displayed multidrug resistance. Furthermore, 29.5% of the samples carried ESBL/AmpC-producing E. coli. In 2020 and 2022, the most frequently determined antibiotic resistances among commensal E. coli isolates were to tetracyclines, sulfonamides and penicillins. In addition, pre-weaned calves had the highest resistance rates in both years. Statistical analyses showed a significant association between low and high use AMU classifications for penicillins (in nDDDvet/cow/year) and their respective resistance among commensal E. coli isolates in 2020 (p = 0.044), as well as for sulfonamide/trimethoprim (p = 0.010) and tetracyclines (p = 0.042). A trend was also noted between the total amount of antibiotics used on farm in 2020 (by nDDDvet/cow/year) and multidrug resistances in commensal E. coli isolated on farm that year (p = 0.067). In conclusion, the relationship between AMU and antimicrobial resistance (AMR) on dairy farms continues to be complex and difficult to quantify.

Oxazolidinone resistance genes in florfenicol-resistant enterococci from beef cattle and veal calves at slaughter

Background

Linezolid is a critically important oxazolidinone antibiotic used in human medicine. Although linezolid is not licensed for use in food-producing animals, the use of florfenicol in veterinary medicine co-selects for oxazolidinone resistance genes.

Objective

This study aimed to assess the occurrence of cfr, optrA, and poxtA in florfenicol-resistant isolates from beef cattle and veal calves from different herds in Switzerland.

Methods

A total of 618 cecal samples taken from beef cattle and veal calves at slaughter originating from 199 herds were cultured after an enrichment step on a selective medium containing 10 mg/L florfenicol. Isolates were screened by PCR for cfr, optrA, and poxtA which are genes known to confer resistance to oxazolidinones and phenicols. One isolate per PCR-positive species and herd was selected for antimicrobial susceptibility testing (AST) and whole-genome sequencing (WGS).

Results

Overall, 105 florfenicol-resistant isolates were obtained from 99 (16%) of the samples, corresponding to 4% of the beef cattle herds and 24% of the veal calf herds. Screening by PCR revealed the presence of optrA in 95 (90%) and poxtA in 22 (21%) of the isolates. None of the isolates contained cfr. Isolates included for AST and WGS analysis were Enterococcus (E.) faecalis (n = 14), E. faecium (n = 12), E. dispar (n = 1), E. durans (n = 2), E. gallinarum (n = 1), Vagococcus (V.) lutrae (n = 2), Aerococcus (A.) urinaeequi (n = 1), and Companilactobacillus (C.) farciminis (n = 1). Thirteen isolates exhibited phenotypic linezolid resistance. Three novel OptrA variants were identified. Multilocus sequence typing identified four E. faecium ST18 belonging to hospital-associated clade A1. There was a difference in the replicon profile among optrA- and poxtA-harboring plasmids, with rep9 (RepA_N) plasmids dominating in optrA-harboring E. faecalis and rep2 (Inc18) and rep29 (Rep_3) plasmids in poxtA-carrying E. faecium.

Conclusion

Beef cattle and veal calves are reservoirs for enterococci with acquired linezolid resistance genes optrA and poxtA. The presence of E. faecium ST18 highlights the zoonotic potential of some bovine isolates. The dispersal of clinically relevant oxazolidinone resistance genes throughout a wide variety of species including Enterococcus spp., V. lutrae, A. urinaeequi, and the probiotic C. farciminis in food-producing animals is a public health concern.

The therapy frequency of antibiotics and phenotypical resistance of Escherichia coli in calf rearing sites in Germany

Introduction

The association between antibiotic use and the occurrence of resistant bacteria is a global health problem and is subject to enormous efforts at national and international levels. Within the scope of the study "KAbMon", the resistance situation as well as the use of antibiotics in calf rearing farms in Germany was investigated. We hypothesized that the levels of resistance are associated with certain calf keeping farm types, such as pre-weaned calf farms, animal groups, and therapy frequency.

Methods

In total, 95 calf keeping farms were visited between October 2019 and April 2021. At each farm, up to three pooled fecal samples (10 freshly released feces each) were collected. One sample was taken in the youngest calf group, another in the oldest calf group, and one in the hospital box, if available. Escherichia coli was isolated from non-selective MacConkey agar. The therapy frequency reflects the average number of treatment days per calf in a half-year, while the resistance score is the sum of the relative minimum inhibitory concentration per substance over all 10 tested substances.

Results

The 1781 isolates from 178 samples showed high resistance rates against sulfamethoxazole (82%), tetracycline (49%), and ampicillin (40%). High resistance scores were mainly found in pre-weaned calf farms (purchasing calves from 2  weeks of life) and in the youngest animals. The therapy frequency showed an almost linear relationship with the resistance scores, and the age at purchase was negatively related to the resistance score.

Discussion

The high use of antimicrobials of young calves might be associated with a high risk for infectious diseases and might indicate that the current system of crowding 14-day-old calves from different farms in one group is not optimal. Further efforts are necessary to educate and motivate the calf keepers to ensure highest levels of hygiene and management as well as animal welfare conditions and to increase animal health.

Antimicrobial Use and Resistance in Surplus Dairy Calf Production Systems

Surplus calves, which consist predominately of male calves born on dairy farms, are an underrecognized source of antimicrobial-resistant (AMR) pathogens. Current production systems for surplus calves have important risk factors for the dissemination of pathogens, including the high degree of commingling during auction and transportation and sometimes inadequate care early in life. These circumstances contribute to an increased risk of respiratory and other infectious diseases, resulting in higher antimicrobial use (AMU) and the development of AMR. Several studies have shown that surplus calves harbor AMR genes and pathogens that are resistant to critically important antimicrobials. This is a potential concern as the resistant pathogens and genes can be shared between animal, human and environmental microbiomes. Although knowledge of AMU and AMR has grown substantially in dairy and beef cattle systems, comparable studies in surplus calves have been mostly neglected in North America. Therefore, the overall goal of this narrative review is to summarize the existing literature regarding AMU and AMR in surplus dairy calf production, highlight the management practices contributing to the increased AMU and the resulting AMR, and discuss potential strategies and barriers for improved antimicrobial stewardship in surplus calf production systems.

Antimicrobial resistance profiles of Escherichia coli and prevalence of extended‐spectrum beta‐lactamase‐producing Enterobacteriaceae in calves from organic and conventional dairy farms in Switzerland

This study compared the antimicrobial resistance (AMR) among commensal Escherichia coli in the fecal microbiota of young calves raised on organic and on conventional dairy farms in Switzerland. Further, fecal carriage of extended‐spectrum beta‐lactamase (ESBL) producing Enterobacteriaceae was assessed for calves from both farming systems. Where possible, data on antimicrobial usage (AMU) were obtained. Antimicrobial susceptibility testing was performed on a total of 71 isolates using the disk diffusion method. ESBL producers were characterized by polymerase chain reaction‐based multilocus sequence typing and sequencing of the bla_ESBL genes. Organically raised calves were significantly more likely to harbor E. coli that showed AMR to ampicillin (odds ratio [OR]: 2.78, 95% confidence interval [CI]: 1.02–7.61, p = 0.046), streptomycin (OR: 3.22, 95% CI: 1.17–8.92, p = 0.046), kanamycin (OR: 11.3, 95% CI: 2.94–43.50, p < 0.001), and tetracycline (OR: 3.25, 95% CI: 1.13–9.31, p = 0.028). Calves with reported AMU were significantly more likely to harbor E. coli with resistance to ampicillin (OR: 3.91, 95% CI: 1.03–14.85, p = 0.045), streptomycin (OR: 4.35, 95% CI: 1.13–16.7, p = 0.045), and kanamycin (OR: 8.69, 95% CI: 2.01–37.7, p = 0.004). ESBL‐producing Enterobacteriaceae (18 E. coli and 3 Citrobacter braakii) were detected exclusively among samples from conventionally farmed calves (OR: infinity [∞], 95% CI: 2.3–∞, p < 0.0013). The observations from this study suggest that AMR is highly prevalent among commensal E. coli in young dairy calves, irrespective of the farm management system, with proportions of certain resistance phenotypes higher among organic calves. By contrast, the occurrence of ESBL producers among young dairy calves may be linked to factors associated with conventional farming.

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.

Antibiotics Use in Food Animal Production: Escalation of Antimicrobial Resistance: Where Are We Now in Combating AMR?

The use of antibiotics has been very beneficial to human health, animal wellbeing, and food production, however, there are no alternatives to antimicrobials in treating infectious diseases. Their use can contribute to the development of antimicrobial resistance, but the world has realized the need to combat antimicrobial resistance in recent decades due to the continued escalation of the problem jeopardizing human and veterinary medicine and food and environmental safety. Understanding the AMR and judicious use of antimicrobials are critical, and one health approach involving several sectors and multiple disciplines is important to tackle the problem. National, regional, and global action plans have been instigated to tackle the escalation of AMR. Antimicrobials are frequently used in food animal production. Therefore, food animal producers are important participants to prevent overuse and misuse of antimicrobials. Recent regulations to address the challenges have not been perceived well in animal farming communities. More awareness regarding these action plans and understanding the impact of AMR are needed. A nationwide survey of perceptions of food animal producers regarding AMR mitigation approaches should be conducted to evaluate the effectiveness of the current policies regarding antibiotics use and AMR. These outcomes should be incorporated in future policies and awareness campaigns targeting food animal producers.

Factors affecting dairy calf price in auction markets in Québec, Canada: 2008-2019

Dairy calves not kept for replacement are sold at young age in Québec auction markets for white and grain-fed veal calf production. The province of Québec produces 80% of the Canadian veal meat, but little information is available on the factors associated with the calves' price per crude weight (Can$/kg; Can$1 = US$0.78 at time of writing). The characteristics of calves sold in Québec auction markets from 12 complete years (2008-2019) were retrospectively studied. The calves' weight, breed and sex, the year and season of sale, the auction site, as well as the estimated distance traveled between the farm of origin and the auction site were analyzed as potential covariates associated with calf price. Two multivariable logistic models associated with low sale value (below the 10th or the 25th percentile of the day price) and 2 models associated with good sale characteristics (above the 50th or the 75th percentile of the day price) were built. The median distance between the farm and the auction site was 52 km (interquartile range: 30-95 km). Only 5% of calves traveled distances greater than 220 km. The weight, breed, sex, and auction sites explained most of the variability in the different models. Distance traveled and multiple interactions were also significantly associated with the outcomes. Calves with body weight from 48 to <56 kg were sold in higher percentiles of the day than lighter or heavier calves. Beef-crossed calves had better sale prices than Holstein, whereas colored dairy calves had lower sale characteristics than both Holstein and beef-crossed calves. The effect of distance traveled was complex, varying depending on the model and interactions, and explained a small portion of the total deviance in every model. Calves traveling from distances ≥110 km had lower sale characteristics in summer and fall in the different studied models. This study gives relevant insights on calves' characteristics associated with good versus low sale prices in Québec auction markets.

Methodology for studying human attitudes and behaviour to cow-calf contact systems

This position paper describes a common stand on methodology of human attitudes and behaviour that is suitable to use in studies regarding cow-calf contact (CCC) in dairy production, in order to create a common knowledge base and foundation for future recommendations of CCC systems. We describe how different quantitative and qualitative methods can be used to study human attitudes to CCC as well as farmer or consumer behaviour. We aim to contribute to a better understanding of the available methods, and hope that this paper can be used as a guideline for future studies in this area.

"They've got to be testing and doing something about it": Farmer and veterinarian views on drivers for Johne's disease control in dairy herds in England

There needs to be an understanding of the reasons why key stakeholders engage in disease control efforts if disease is to be successfully and sustainably controlled. It is increasingly recognised within veterinary epidemiology and policy making in animal health that these 'people factors' are important influences on the success or otherwise of animal disease control programmes. Research methodologies adopted from the social sciences offer ways to understand this important dimension through investigating the attitudes and opinions of the key actors involved. The study reported in this paper, based on qualitative interview research, investigates the views of dairy farmers and cattle veterinarians on the drivers and incentives for controlling Johne's disease in English dairy herds. Twenty semi-structured interviews involving 17 dairy farmers and seven veterinarians were conducted in two dairy-intensive regions of England. The findings demonstrate the varied influences of veterinary advice and encouragement; appreciation of the economic cost of the disease at herd level; a voluntary national control plan; and fear of a future consumer food scare as the main reasons to engage in Johne's disease control on dairy farms. The study demonstrates how a combination of a voluntary industry-led control scheme, compulsory participation through retailer and processor contractual requirements, and threats of reputational harm and market loss have strongly influenced farmer and veterinary behaviour in relation to Johne's control without statutory involvement. The findings illustrate the importance of considering the political economy and societal impact of animal disease.