Biosecurity and animal disease management in organic and conventional Swedish dairy herds: a questionnaire study

Living labs opened dialogues about antibiotic use in dairy cattle and pig sectors - Insights from a Danish case study based on participatory action research

BACKGROUND

Prudent antimicrobial use (AMU) is paramount for future sustainable animal production. Continuous efforts are required to have a low and well-regulated AMU. Living Labs (LLs) are multistakeholder open innovation platforms that have the potential to allow multiple stakeholders to explore common ground, create dialogues and find solutions to jointly identified problems. The purpose of this study was to stimulate multistakeholder dialogues leading to transitions towards a more prudent AMU in the Danish dairy and pig sectors.

RESULTS

The two LLs, which focused on pig farms and dairy cattle farms, worked in parallel for 30 months. Stakeholders in the pig and dairy sectors pointed to systemic structures such as logistic conditions and global market structures as the main drivers of the current AMU. Both LLs expressed conflicting interests and perceptions around the concept of prudent AMU related to animal welfare and today's production systems. Thus, the LLs in the Danish context became spaces for opening dialogues and negotiating difficult and sensitive issues in addition to being open-innovation platforms. Both LLs expressed scepticism around the connections between AMU in animal farming and the global threat of antimicrobial resistance to humans. However, this scepticism was more dominant for the stakeholders of the pig sector. The feeling of being a global front-runner in prudent AMU, legislation and transparent monitoring of AMU existed in both sectors, but both LLs identified possibilities and room for improvement. The need to reduce AMU was most consistently articulated in the dairy cattle LL, where the stakeholders increasingly focused on calves from dairy farms and the systemic drivers, which made it challenging to reduce AMU. Some actors in the pig LL kept questioning whether a change towards more prudent AMU was needed in Denmark.

CONCLUSION

The LL approach fostered important dialogues and insights between central stakeholders in the sectors and was thereby helpful in terms of opening and contributing to dialogues about antibiotic usage in dairy cattle and pigs within and across sectors.

Biosecurity adoption in Québec dairy farms: Results from a risk assessment questionnaire analyzed using conventional and unsupervised artificial intelligence methods

This study documents the current state of biosecurity on dairy farms in Québec following the implementation of a mandatory biosecurity risk evaluation that was part of the proAction accreditation program developed by Dairy Farmers of Canada. Using a cross-sectional design, 3,825 risk assessment questionnaires completed between 2018 and 2021 were extracted from Vigil-Vet database, which is a software used by veterinarians for conducting the proAction risk assessment. Descriptive statistics were used to summarize the practices adopted by dairy producers. Additionally, multiple correspondence analysis was used to explore the association between the diseases of most concern and the adoption of biosecurity practices. Moreover, we used a hierarchical cluster analysis on principal components to identify distinct patterns of biosecurity practices among dairy producers. This analysis enabled the identification of typologies or clusters of farms based on the specific biosecurity practices they currently employ. The results of the descriptive statistics indicated that mastitis was the disease of most concern for most dairy farmers (40%). Moreover, given that only 10% of the 2,237 dairy farmers who acquired animals adhered to quarantine practices, there seems to be a need for improved implementation of biosecurity measures aimed at restricting the introduction of diseases when introducing new animals. Conversely, cleaning stalls and health equipment were adequately addressed by 95% and 86% of dairy producers, respectively. The multiple correspondence analysis indicated no significant association between the disease of most concern and the farm's biosecurity profile, except for respondents who identified digital dermatitis as their disease of most concern. Through the hierarchical cluster analysis, 3 clusters were identified among 3,581 farms: (1) Cluster 1 included farms with good management of sick animals; (2) Cluster 2 included farms with good management of young animals; and (3) Cluster 3 included farms with poor management of sick animals and young animals. Our study makes an important contribution by providing valuable insights into the biosecurity practices currently adopted on Québec dairy farms. It establishes a baseline for assessing progress in biosecurity practices adoption and serves as a reference point for future evaluations. In addition, these findings play a key role in monitoring the effectiveness of interventions aimed at improving biosecurity on dairy farms. By making use of this knowledge, stakeholders can make informed decisions that prioritize animal health, increase productivity, and ensure sustainability of the dairy industry.

Persistence of Staphylococcus spp. in milk from cows undergoing homeopathy to control subclinical mastitis

Background

Mastitis is one of the major diseases in dairy cattle, as it causes great economic losses to producers due to the reduction of milk production and changes in the quality of the product. The disease is mainly caused by bacteria of the genus Staphylococcus spp., these microorganisms can express various virulence factors, such as biofilms for example. In herds with organic management, producers and technicians use unconventional ways to treat and control the disease, such as homeopathy. However, it is not known if this type of treatment is able to control pathogenic bacteria such as those of the genus Staphylococcus, of relevance to animal and human health. Thus, the objective of this study was to investigate the production of biofilm in vitro and its genes by Staphylococcus spp. isolated in the milk of cows treated with homeopathy, as well as the persistence of microorganisms in animals.

Methods

Ninety-nine isolates of Staphylococcus spp. from cows treated and not treated with homeopathy were identified by internal transcribed space-polymerase chain reaction and investigated for the presence of the icaABCD, bap, aap, atlE, and bhp genes and in vitro biofilm production using the adhesion method on polystyrene plates. The enzyme restriction profile was determined by Pulsed-Field Gel Electrophoresis. Clusters of S. aureus and S. epidermidis with three or more isolates had an isolate selected for Multilocus Sequence Typing.

Results

The frequency of S. aureus isolations was similar in treated and untreated cows, while 71.4% of the coagulase-negative identified were isolated in cows treated with homeopathy. The distribution of the operon ica genes was similar in animals with and without treatment, except for the icaD gene, more frequent in treated cows. Production of biofilm was associated with presence of one or more genes from the icaADBC operon. S. aureus revealed a greater diversity and greater dissemination in cows treated and not treated with homeopathy. Sequence Types ST1, ST5, and ST126 were identified in S. aureus.

Conclusions

The presence of biofilm-associated genes and the in vitro production of biofilms, combined with the persistence of clonal profiles of Staphylococcus spp. demonstrate other forms of control for bovine mastitis should be researched for organic production herds.

Economic analysis of biosecurity adoption in dairy farming: Evidence from Ireland

Given the significant negative impact of livestock disease outbreaks on animal and public health, preventing disease spread through biosecurity practices is important. In this study, we used a nationally representative dataset that included information on biosecurity practices of almost 300 Irish dairy farmers. We applied parametric and nonparametric estimation methods to assess the economic implications of adopting the following biosecurity measures: vaccination, bulk tank milk testing for diseases, and not pooling colostrum. We found mixed evidence of biosecurity practices on economic outcomes, measured as gross margins per cow. Specifically, we found that vaccination and testing bulk tank milk for diseases were significantly associated with better economic outcomes for dairy farms. However, we found no significant association with the economic performance of not pooling colostrum from more than one animal. Our findings have important policy implications required for targeting support for the adoption of biosecurity practices in dairy herds.

Do animal health models meet the needs of organic and conventional dairy farmers in Spain and the UK on disease prevention?

Modelling plays an important role in assessing disease risks and the efficacy of preventative actions. However, the extent to which existing models meet the needs of different groups of dairy farmers around disease prevention is unclear. A questionnaire gathered information on disease prevention actions undertaken by organic and conventional dairy farmers in Spain and the UK, and on their information preferences and needs in relation to such actions. A systematic review of animal health modelling articles was undertaken to compare the expressed needs of dairy farmers for information on disease prevention, with the focus and outputs of existing models. Farmer groups differed in needs when planning disease prevention interventions. Most farmers sourced animal health information from veterinarians. Farmers preferred to use practical experience to judge the efficacy of change. To fulfil the expressed needs of dairy farmers, models need to address specific farming contexts and non-economic impacts of change.

The use of item response theory models to evaluate scales designed to measure knowledge of, and attitudes toward, antibiotic use and resistance in Swedish dairy producers

Scales are frequently used to quantify latent traits that can not be measured directly (eg knowledge of a subject, attitude toward an issue, severity of a clinical condition). Historically, little attention has been paid within veterinary medical sciences to evaluating how well these scales perform. In this study methods that can be used in this evaluation were reviewed and applied to scales quantifying two unmeasurable traits: knowledge of, and attitudes toward, antibiotic use and resistance in Swedish dairy farms. Items (questionnaire questions) that did not fit well with the assumed unmeasurable trait were identified and removed. Item response theory models were applied to the remaining items to determine how well they contributed to the scale using item characteristic curves and a variety of information functions. A graphical evaluation of the fit of the models to the data was then carried out. For the knowledge scale, the evaluation identified a number of items which did not fit well with the scale. It subsequently demonstrated that the scale did a good job of discriminating among producers with below average knowledge, but had very little ability to separate average producers from those with a high level of knowledge. Similarly, the attitude scale did well at discriminating among producers with an average or poor attitude toward reducing their own antibiotic use, but had little ability to distinguish among those with above average attitudes. Item response theory models are valuable for determining how well items contribute to predicting an individual's value of the latent variable and whether or not there are "gaps" in the scale which are not measured well. Guidelines for the use of these methods in the development or refinement of scales are presented. Their post-hoc use to verify the performance of scales in preparation for subsequent analyses is also discussed.

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.

The Use of Activated Micronized Zeolite Clinoptilolite as a Possible Alternative to Antibiotics and Chestnut Extract for the Control of Undifferentiated Calf Diarrhea: An In Vitro and In Vivo Study

Simple Summary

Today, zeolite has appeared as an interesting alternative for the symptomatic treatment of acute diarrhea. Therefore, this study aimed to investigate the properties of activated micronized (five microns) zeolite clinoptilolite (MZC) from Transylvania, Romania, first by testing it in vitro and then in vivo on calves with diarrhea. To assess the toxic potential of MZC, we performed a cell cytotoxicity assay on cells of bovine origin, while its antimicrobial activity was investigated on Escherichia coli. The uncontrolled in vivo study was carried out over 8 days on a fattening farm, with some 650 calves. Selected calves were randomly assigned to 4 groups of 20 individuals. Several combinations between activated MZC, chestnut extract, and oxytetracycline were tested. At the beginning of the study, all calves had diarrhea, while at the end of the study, the prevalence of diarrhea was significantly lower in all four groups (p < 0.001), including the ones treated with MZC. Due to its low cytotoxicity on the intestinal cells and with regards to the results we obtained in vivo, MZC could represent an alternative method to reducing the amount of antimicrobials needed for the symptomatic treatment of diarrhea in calves, therefore contributing to the reduction of the antimicrobial resistance phenomenon.

Abstract

Today, zeolite appears as an interesting alternative for the symptomatic treatment of acute diarrhea. Therefore, this study aimed to investigate the properties of activated micronized (5 microns) zeolite clinoptilolite (MZC) from Transylvania, Romania, first by testing it in vitro and then in vivo on calves with diarrhea. To assess the toxic potential of the MZC, we performed a cell cytotoxicity assay using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) technique on primary bovine intestinal epithelial cells (BIECs). The antimicrobial activity of MZC was investigated by measuring the minimal inhibitory concentration (MIC) on Escherichia coli (ATCC 25922). The uncontrolled in vivo study was carried out over 8 days on a fattening farm, with some 650 calves. Selected calves were randomly assigned to four groups of 20 individuals. Several combinations between MZC, chestnut extract, and oxytetracycline were tested. At the beginning of the study, all calves had diarrhea, while at the end of the study, the prevalence of diarrhea was significantly lower in all four groups (p < 0.001), including the ones treated with MZC. Due to its low cytotoxicity on the intestinal cells and with regards to the results we obtained in vivo, MZC may be considered an alternative for the symptomatic treatment of undifferentiated diarrhea in calves.

Antibiotic Use in Organic and Non-organic Swedish Dairy Farms: A Comparison of Three Recording Methods

Biases of antimicrobial use (AMU) reporting systems pose a challenge to monitoring of AMU. Our study aimed to cross-compare three data sources of AMU in Swedish dairy herds to provide an account of the validity of AMU reports. We studied AMU differences between two production systems, to investigate how the reporting system affected this comparison. On-farm quantification of AMU via a manual collection of empty drug containers (BIN) took place in organic (n = 30) and conventional (n = 30) dairy herds during two periods between February 2016 and March 2017. A data extract mirroring these periods was obtained from two linked datasets that contain AMU data as reported by the prescribing veterinarians. These included data from the Swedish Board of Agriculture system (SBA) and Växa milk recording system (VXA). Using the European Medicines Agency technical units, the total number of defined daily doses (DDD_vet), and defined course doses (DCD_vet) per animal/year were calculated for each herd/period/dataset. Descriptive statistics and Bland–Altman plots were used to evaluate the agreement and systematic bias between the datasets. Mixed models for repeated measures were used to assess AMU differences between production systems. We found consistent numerical differences for the calculated AMU metrics, with BIN presenting higher usage compared to the SBA and VXA. This was driven by a disparity in intramammary tubes (IMt) which appear to be underreported in the national datasets. A statistically significant interaction (BIN dataset) between the production system and drug administration form was found, where AMU for injectable and lactating cow IMt drug forms differed by the production system, but no difference was found for dry-cow IMt. We conclude that calculating AMU using DDD_vet and DCD_vet metrics at a herd level based on Swedish national datasets is useful, with the caveat of IMt potentially being misrepresented. The BIN method offers an alternative to monitoring AMU, but scaling up requires considerations. The lower disease caseload in organic herds partly explains the lower AMU in particular drug forms. The fact that organic and conventional herds' had equally low AMU for dry-cow IMt, coupled with mismatches in IMt report across herds indicated an area of further research.

A survey of biosecurity measures and serological status for bovine viral diarrhoea virus and bovine herpesvirus 1 on dairy cattle farms in north-west and north-east Spain

BACKGROUND

Biosecurity is a key measure to reduce and prevent the introduction of diseases to farms and minimise spread of diseases within a herd. The aim of the study was to characterise the current application of biosecurity measures on dairy cattle farms in Spain along with their bovine viral diarrhoea and infectious bovine rhinotracheitis status.

METHODS

Data on biosecurity measures for 124 dairy herds were collected using a questionnaire. The sanitary status of these farms for bovine viral diarrhoea and infectious bovine rhinotracheitis was also assessed using antibody ELISA. Data were analysed using multiple correspondence analysis and a two-step cluster analysis.

RESULTS

Three main clusters of farms were identified: clusters 1 and 2 included herds of small and intermediate sizes. These, particularly cluster 1, showed the most deficiencies in the control of vehicles and visitors. However, laboratory tests were always performed on purchased animals. Cluster 3 had the largest herd sizes, with somewhat better biosecurity control of vehicles and visitors. However, farms in this cluster also purchased the most animals, sometimes without testing, and hired external workers more often.

CONCLUSION

The study indicated that, in the study population, there are serious shortcomings in the application of biosecurity measures on dairy farms, exposing them to disease transmission. This survey also highlights regional and herd size-related differences in the implementation of biosecurity. Collecting data is an important first step to identification of specific weaknesses in different farm typologies, and an adequate follow-up is needed to ensure that measures are implemented correctly on farms.

Gap between producers and veterinarians regarding biosecurity on Quebec dairy farms

As part of the ProAction on-farm program to implement national biosecurity requirements on dairy farms, Canadian veterinarians are called upon to complete biosecurity risk assessments. The objective of the present study was consequently to understand veterinarians' perceptions of biosecurity, and to compare perceptions among producer-veterinarian pairs. Questionnaires were administered to 106 producers from Quebec and their veterinarians (n = 82), and the answers of the producer-veterinarian pairs were compared. While most veterinarians reported it was easy to discuss biosecurity with their clients, most veterinarians and producers did not report discussing biosecurity. Moreover, when producers or veterinarians reported discussing biosecurity topics, there was no agreement amongst pairs. Veterinarians also misjudged how their clients perceived the importance and usefulness of biosecurity. Finally, veterinarians reported they had the knowledge and opportunity to assess and discuss biosecurity on dairy farms but lacked skills for evaluating farms and communicating their knowledge.

Milk Potential of Pantaneira Cows, a Local Breed, at Organic System

Simple Summary

Pantaneira cattle are descendants of the genetic group of crossed European animals and are a breed locally adapted to the Brazilian Pantanal. The use of this breed in organic systems can have benefits for the conservation of the breed and because it is a genetically rustic breed. The aim of this study was to evaluate the performance of Pantaneira primiparous cows under systems with reduced use of concentrate, simulating organic production conditions. There was a reduction in milk yield, but the energy-corrected milk yield and efficiency were not affected. The Pantaneira breed has the genetic potential for the maintenance of competitive production and quality in organic systems.

Abstract

Pantaneiro cattle (Bos taurus taurus) is a breed locally adapted to the Brazilian Pantanal. Local breeds are essential for the quality production of organic systems based on planned grazing practices, because of their results in resilient and productive ecosystems, enhancing biodiversity. This study aimed to evaluate the performance of Pantaneira primiparous cows, and systems with reduced use of concentrate, simulating organic production conditions. Five animals, with an average body weight of 396.2 ± 43.5 kg, were kept in individual continuous grazing regimes and supplemented with different concentrate levels (1.2%, 0.9%, 0.6%, 0.3%, and 0.0% of body weight). The animals were allocated at random in a 5 × 5 Latin square design repeated twice during the study time. The cows had a low dry matter and nutrient intake with a reduction in concentrate level, with improvement in neutral detergent fiber digestibility and a reduction in total nutrient digestibility. No changes were observed in plasma glucose levels or urea excretion, but the plasma urea nitrogen decreased with reductions in concentrate levels. There was a reduction in milk yield, but the energy-corrected milk was not affected by the reduction in concentrate levels; furthermore, the milk yield efficiency was not affected. The milk fat content improved with the reduction in concentrate levels. The Pantaneira breed has the genetic potential for the maintenance of competitive production and quality in organic systems.

Knowledge, attitude and practices of Swiss dairy farmers towards intramammary antimicrobial use and antimicrobial resistance: A latent class analysis

Understanding farmers' mindsets is important to improve antimicrobial stewardship in the dairy industry. This cross-sectional study aimed to determine farmers' knowledge, attitude, and practices with respect to lactational intramammary antimicrobial use (AMU) and antimicrobial resistance (AMR) in Swiss dairy herds. Based on their approach towards subclinical mastitis (SCM) and non-severe cases of clinical mastitis (CM), subgroups of farmers were identified and compared regarding their knowledge, attitude and practices towards AMU and AMR. After conducting qualitative interviews to develop a questionnaire, an online survey was sent to 1296 randomly selected Swiss dairy farmers. Information was gathered on demographic data and farmers' knowledge, attitude, and practices towards AMU and AMR. A latent class analysis was performed to identify subgroups of farmers based on management of SCM and non-severe CM cases. Based on the results of 542 completed questionnaires, poor knowledge with respect to AMU and AMR was identified, as well as discrepancies between farmers' perceptions and their actual practices. Farmers approached cows with SCM and non-severe CM similarly, indicating they perceived both mastitis states as the same disease. Intramammary antimicrobial products containing cefquinome, which is a highest priority critically important antimicrobial, were among the 3 most commonly applied intramammary antimicrobials. Five latent classes of farmers were identified based on their management towards SCM and non-severe CM. One group of farmers (18.5% of respondents) indicated that they did not treat those mastitis cases, one group only treated SCM cases (13.8% of respondents), one group only treated non-severe CM cases (28.6% of respondents) and the largest group treated both mastitis states (39.1% of respondents). The latter group was subdivided into a latent class of farmers following guidelines for AMU/AMR (25.5% of respondents) and a group of farmers that were not strictly following these guidelines (13.7% of respondents). Regional differences between farmers, according to altitude and language region, explained some of the variation in latent class membership. Latent class membership was associated with farmers' attitude to use antimicrobials as little as possible and with using antimicrobials only after performing bacteriological and susceptibility testing. This study gave detailed insight into Swiss farmers' knowledge, attitude, and practices regarding AMU and AMR and provides opportunities to improve antimicrobial stewardship in Swiss dairy herds. The identified groups of farmers, based on their management practices regarding SCM and non-severe CM, may help to design tailored intervention strategies for improving prudent AMU in the heterogeneous population of dairy farmers in Switzerland.

Biosecurity and herd health management practices on Canadian dairy farms

The Canadian dairy industry has created national standards to support the adoption of biosecurity practices and to reduce disease risks across the country. There is, however, very little information on the adoption of these practices. The present study aimed to describe the adoption of biosecurity practices on Canadian dairy farms shortly after the creation of the national standards and to identify demographic factors associated with practice adoption. In 2015, 2 questionnaires (phase 1 and 2) were administered to Canadian dairy farmers during an extensive cross-sectional study. Associations between adoption of biosecurity practices as well as associations between adoption of these practices and demographic variables were tested using multiple correspondence analysis. A total of 1,157 questionnaires were completed in phase 1, and a subsample of 368 respondents was selected using stratified random sampling to complete phase 2 during visits to the farms. There was a lack of investigation into general disease syndromes such as a high prevalence of abortion or an unexplained death (38 and 22% of respondents, respectively). Biosecurity measures within herds and between herds to minimize the spread of infection were not widely adopted (e.g., 27% of the respondents never housed sick or lame animals in their calving pen, 41% had closed herds, and 25 and 48% of the open herds had no strategy for introducing new additions and reintroducing returning animals, respectively). Cleanliness of the cows before calving was always ensured by 29% of the respondents, and 27% of the respondents reported always sanitizing the calving pen after each calving. Less than 15% of the respondents had measures in place to limit or control visitors coming on their farm. Moreover, less than half of the respondents reported requiring family members, employees, and visitors to wear farm-designated or clean boots and coveralls. From the multiple correspondence analysis, 2 dimensions were retained and were summarized as "animal movement, calving area, and visitor biosecurity" and "employee biosecurity." Geographical region, type of housing, and milk production were associated with the "employee biosecurity" dimension. The present study demonstrates that many important biosecurity practices are not implemented on Canadian dairy farms; therefore, efforts to promote the adoption of these practices will be necessary to improve biosecurity in dairy herds.