The Swedish dairy sector is undergoing rapid structural transformation, marked by a sharp decline in farm numbers and a concurrent increase in herd sizes. This development raises concerns about the long-term sustainability and resilience of rural food systems. This study explores the perceived challenges and needs of Swedish dairy farmers, with a particular focus on how these perceptions differ by herd size. A national survey of 326 active dairy farms was conducted, combining statistical analyses of quantitative data with qualitative analysis of free-text responses. The analysis was framed within a systems perspective, considering farm-level, local, and broader systemic factors. Six overarching thematic areas were identified: working environment, farm succession, economy, resource management, politics, and the societal role of dairy farming. While these areas were shared across farms, smaller farms (≤79 cows) more often emphasized challenges related to work-life balance, generational renewal, and the recognition of environmental and cultural values. Larger farms prioritized labour availability, operational efficiency, and regulatory flexibility. The findings suggest that current institutional structures are better aligned with the needs of larger farms, potentially marginalizing smaller operations. Profitability was a central concern for all farms, not only as a financial goal but as a means to maintain strategic flexibility and long-term viability. We argue that maintaining a diversity of farm sizes and production systems is essential for building a resilient and regionally inclusive dairy sector. Our results are of high relevance to tailor policy and advisory efforts to support such diversity by addressing needs of different farm types.

Abstract Background and objectivesSwedish dairy production has become increasingly dependent on imported feed, fertiliser and energy, raising concerns about long‑term resilience and national food security. Forage‑based feeding strategies have been proposed to reduce external dependence, but their implications for productivity, udder health and reproductive performance under Swedish conditions remain unclear. This study compared herd‑level indicators of milk production, udder health, fertility and metabolic status between Swedish dairy herds managed with low or high forage proportions.Data collectionHerds were classified as low forage (<55% forage) or high forage (>65% forage) based on 10‑month lactation diets. Herd‑level data on milk yield, energy‑corrected milk (ECM), somatic cell count (SCC), reproductive performance and milk urea were obtained from the Swedish official milk‑recording scheme and analysed using mean values from 2018–2024.Research methodsAnalyses were performed at the herd level using annual aggregated data. Multivariable mixed‑effects models were fitted for all outcomes, adjusting for herd size, breed and geographical region, with herd ID included as a random intercept to account for repeated annual observations.ResultsLow‑forage herds produced on average 2,200 kg more ECM per cow and year than high‑forage herds, and this difference remained after adjustment. Udder health indicators were broadly similar between systems, with small and imprecisely estimated differences in SCC. Reproductive indicators showed no clear evidence of system‑level differences. High‑forage herds had a higher proportion of cows with low milk urea values, and low‑forage herds had lower odds of low urea in adjusted models, indicating a distinct nitrogen balance between strategies. The fat‑to‑protein ratio, based on herd‑level annual averages, showed no clear system differences.ConclusionsHigh‑forage systems appear able to maintain stable udder health and fertility outcomes despite lower concentrate use, although with an expected reduction in milk yield.ContributionsThis study provides new herd‑level evidence under Swedish conditions on how contrasting forage proportions relate to milk production, udder health, fertility and metabolic indicators. It contributes national‑scale data on milk urea and fat‑to‑protein ratio differences between forage‑based feeding strategies and confirms that high‑forage systems can maintain health and fertility despite lower concentrate use.

Access to mechanical brushes enables grooming behaviour in dairy cows and has shown benefits for cow welfare, including improved cleanliness, comfort, stress reduction. Brush-use may also promote a positive emotional state. Reduced brush use has been associated with health issues, suggesting its potential for automated health monitoring. This study aimed at evaluating whether data generated by pose estimation could be used to assess brush use patterns in loose-housed dairy cows. It presents an approach for automatically identifying the body segment being brushed as an application of pose estimation. Data collection was carried out at the Swedish Livestock Research Centre in a loose housing system equipped with an automatic milking system and two mechanical rotating brushes. Recordings spanned 25:30 h and used three cameras, at different positions, monitoring a single mechanical brush placed in a passageway between cubicle rows. One human observer with access to recordings from all three synchronized cameras annotated the data-set on a second-by-second basis. The observer recorded: (1) the number of cows using the brush; (2) the anatomical segment being brushed; and (3) whether brushing resumed after a pause. The same video recordings were processed with object detection and pose estimation, which predicted the location of bounding boxes for cows and for the brush as well as corresponding keypoints. Using the brush and cow keypoint locations, we attempted to detect brushing by anatomical region. In a first stage, machine-learning models were trained to predict brushing state (independent of location) using keypoint distance to the brush, achieving an accuracy of 86.3 %. To mitigate the risk of error propagation, we relied on human annotations to segment the video to confirmed brushing bouts for analysis in the second stage. To identify the anatomical location of brushing, two methods were evaluated: (1) simply assigning the brushing location to the closest keypoint, achieving 73 % average accuracy across classes, and (2) projecting brush and anatomical keypoints onto a spline modelling the cow's backline, resulting in 87 % accuracy. Misclassifications were predominantly limited to adjacent body segments. Given that intra-observer reliability was 90 %, the spline-based method was deemed sufficiently reliable for research applications to accurately monitor the specific body segments being brushed.

Farmers play a key role in mastitis management, particularly in deciding whether and when to contact a veterinarian or initiate treatment. This cross-sectional study aimed to investigate how herd udder health status (measured as average herd SCC), relates to farmers' health-seeking behavior, and how this behavior is influenced by farmers' herd-level udder health perception, perceived control, motivational values, and production system (organic vs. conventional). A survey was distributed to 697 Swedish dairy farmers using automatic milking systems, with 244 complete responses and 164 included in the final analysis. Farmers were presented with 3 mastitis scenarios and categorized into 4 groups based on their treatment intentions. With the self-regulation model of illness as a theoretical framework, we applied a serial multiple mediator model to explore the relationships between objective herd health, psychological constructs, and treatment behavior. Results showed that average herd SCC was not directly associated with farmers' treatment decisions. Instead, herd-level udder health perception, perceived control, and both economic and noneconomic motivation significantly influenced health-seeking behavior. Among organic farmers, perceived control and economic values had a direct effect, although no significant pathway was found among conventional farmers. These findings highlight the importance of addressing farmers' subjective perceptions and motivations in advisory strategies to improve mastitis management and animal welfare outcomes.

The structure of cubicles can hinder cows’ movements when transitioning between postures, leading to atypical motion patterns. Assessing posture transitions relies on visual observations. This study presents a framework for complementing these assessments with kinematic measurements using 3D pose estimation. A total 809 rising and 791 lying down posture transitions were recorded over 12 cubicles by 7 synchronized cameras and processed with 3D pose estimation locating the position of the poll, withers, T13 and sacrum. First, the displacement of the keypoints was used to detect phases of the posture transitions. This detection was compared with visual observations of 200 recordings. The average mean absolute difference in detected timestamps between human and machine across all phases was 0.5 s (average σ = 0.7) and was under 0.9 s for all phases. Second, indicators were scored based on spatial use and duration, and their distribution compared to existing thresholds. We observed that 59.9 % of rising bouts and 29.1 % of lying down bouts exceeded at least one threshold. Rising delay occurred in 2.8 % of rising bouts and backwards crawling in 59.2 %. Lying down duration exceeded the threshold in 28.9 % of bouts, and rear limbs shifting duration in 8.3 %. Side lunge had a binary threshold which was not adapted to continuous sensor data. Finally, we investigated the association between indicators and found distinct dimensions for head lunge and crawling. We conclude that 3D pose is useful to score posture transition indicators, and that several indicators should be used together to capture distinct dimensions.

undergo post-mortem examination (Swedish Veterinary Agency, 2022).This means that the reported cause of death is often based on the farmers own assessment, which can be misleading or even incorrect (McConnel et al., 2009;Thomsen et al., 2012;Alvåsen et al., 2014).The limited numbers of post-mortem examinations of Swedish cattle might be due to logistical barriers, e.g., transport of the cadaver to a post-mortem site within a reasonable time.In Sweden, the cost of a post-mortem examination at a

Free stall comfort is reflected in various indicators, including the ability for dairy cattle to display unhindered posture transition movements in the cubicles. To ensure farm animal welfare, it is instrumental for the farm management to be able to continuously monitor occurrences of abnormal motions. Advances in computer vision have enabled accurate kinematic measurements in several fields such as human, equine and bovine biomechanics. An important step upstream to measuring displacement during posture transitions is to determine that the behavior is accurately detected. In this study, we propose a framework for detecting lying to standing posture transitions from 3D pose estimation data. A multi-view computer vision system recorded posture transitions between Dec. 2021 and Apr. 2022 in a Swedish stall housing 183 individual cows. The output data consisted of the 3D coordinates of specific anatomical landmarks. Sensitivity of posture transition detection was 88.2% while precision reached 99.5%. Analyzing those transition movements, breakpoints detected the timestamp of onset of the rising motion, which was compared with that annotated by observers. Agreement between observers, measured by intra-class correlation, was 0.85 between 3 human observers and 0.81 when adding the automated detection. The intra-observer mean absolute difference in annotated timestamps ranged from 0.4s to 0.7s. The mean absolute difference between each observer and the automated detection ranged from 1.0s to 1.3s. There was a significant difference in annotated timestamp between all observer pairs but not between the observers and the automated detection, leading to the conclusion that the automated detection does not introduce a distinct bias. We conclude that the model is able to accurately detect the phenomenon of interest and that it is equatable to an observer.

BackgroundAll-in, all-out with strict hygienic routines is necessary in modern pig production. Furthermore, a standardised, validated method is needed to quantitatively control the effect of these hygiene protocols. This study aimed to establish a reproducible and reliable sampling method to assess cleaning of the pig pen.MethodsSterilised pig faeces were mixed with indicator bacteria (i.e. Enterococcus hirae, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus) and spread out in a controlled environment. The retrieval rate of three different sampling methods were evaluated; swabbing by (i) a cloth and (ii) a sponge, analysed by standardised bacterial culture and counting of colony-forming units, and (iii) a cotton swab analysed by adenosine triphosphate (ATP) bioluminescence. Two time-points were evaluated during the study; after drying overnight and after manual scraping of the surfaces. To determine sample-to-sample variability, sampling by the cloth and the cotton swab was carried out after manual scraping and further, after high-pressure washing with cold water.ResultsSampling by the cloth and the sponge showed few differences in in the number of CFU obtained before and after the manual scraping (retrieval rate), whereas the swabs, measuring ATP bioluminescence, showed a very high retrieval rate. Sample-to-sample variability was low for all three methods.ConclusionsIn conclusion, to sample pens for the presence of bacteria, the cloth was assessed as the preferable material, being cheap, easy, specific, and approachable, and with a low sample-to-sample variability. The ATP measurement could have potential for use when evaluating the cleaning of stables, however, threshold values for evaluating the cleaning of a pig sty needs to be developed.

IntroductionWhile early separation of dairy calves after birth has been debated from an ethical and animal welfare lens, the economic evidence surrounding alternative cow-calf contact (CCC) systems is scarce.MethodsTo address this knowledge gap, we assessed the economic consequences of CCC systems using data from the Agriwise database as well as parameters from published literature in a stochastic partial budget model. The implementation of CCC is very diverse between farms, so in our study we therefore selected a limited number of CCC systems to assess. The examined CCC systems were: (i) dam rearing with limited contact at milking (15 minutes twice a day for 115 days) with no manual milk feeding; (ii) dam rearing with 21-day full contact, after which calves are manually fed 8 kg of whole milk for 94 days; and (iii) mixed calf rearing with using both dams and foster cows with full contact; calves are initially kept with their dams and then moved to foster cows at 9 days of age.ResultsWe found that adoption of CCC systems was associated with decreases in contribution margins in the range of 1 to 5.4%, as compared to a rearing system where the calves were separated from their dams after one day and were manually fed 8 kg of milk for 12 weeks. These results illustrated that the costs associated with CCC systems may be fairly high under certain circumstances and may prohibit farmers from adopting this practice. Sensitivity analysis suggested that differences in milk sales, assumptions on changes in labor requirements, and changes in daily calf weight gain depending on CCC system were the main variables that governed the net impact on the contribution margins.DiscussionWe did not include building costs in the analyses assuming that barn structures may not change in the short-term. The study focused only on short-term pecuniary associations between changes in CCC systems and contribution margins. To strengthen the economic decision-making around CCC systems, future research should consider non-monetary impacts of different CCC systems, as well as long-term economic impacts of these production strategies.

Studies have shown that farmer-veterinarian relation-ships influence antimicrobial use (AMU) in livestock, though how they do so is unclear. On the one hand, research shows that well-established veterinarian -farmer relationships are positive for implementation of antibiotic stewardship and restrictive AMU. On the other hand, studies also show that farmer demands can increase antimicrobial prescribing and that prescribing antimicrobials can strengthen the veterinarian's rela-tionship with farmer clients. In the present study, we focus on veterinarians' perspectives on the relationships between dairy cattle farmers and veterinarians in Swe-den and explore what characterizes these relationships when restrictive AMU is described as unproblematic and when AMU becomes a matter of tension or con-flict. The study draws on semistructured interviews with 21 veterinarians working with livestock in Swe-den. Interviews were analyzed thematically. The study shows that from the perspectives of veterinarians, well -established veterinarian-farmer relationships generally facilitate restrictive AMU in 3 slightly different but related ways: (1) they create trust in the veterinarian and their prescribing decisions; (2) they create shared understanding concerning when antimicrobials are needed and not needed; and (3) they facilitate construc-tive discussions between veterinarians and farmers on AMU. To make the farmer feel listened to and to come to an agreement on AMU was described as central for the veterinarians. However, the veterinarians described agreements on restrictive AMU as sometimes requir-ing strategic work, such as discussions to motivate the farmer and leave the door open for antimicrobials later if needed. Such work takes time and energy and is easier within well-established relationships according to the veterinarians. We also identified examples where veterinarians explained that they occasionally make compromises with farmers concerning antimicro-bials-compromises that, according to the veterinar-ians, facilitate the relationship with the farmer, which in turn facilities restrictive AMU in the longer term. The examples in our interviews where antimicrobials became a matter of tension and even conflict between veterinarians and farmers could, with a few exceptions, be traced to absence of well-established relationships. However, some veterinarians also described AMU as a matter of tension within well-established relationships, especially with older farmers who do not trust new treatment strategies. We also found a small number of examples where disagreements on antimicrobials made a relationship with specific farmers impossible. Thus, even though the interviewed veterinarians generally meant that their restrictive antimicrobial prescribing did not threaten the relationship with the farmer, our study also, to some extent, confirms research showing that restrictive AMU can harm the relationship with some clients who simply choose another, less restric-tive, veterinarian. In summary, our study supports that decisions on AMU cannot be reduced to the individual prescriber's behavior, nor to a strict medical judgment. Antimicrobial use for dairy cattle needs to be under-stood as taking form in relationships in which both veterinarians and farmers are active parts.

Mastitis is a production disease in dairy farming that causes economic losses. Especially chronic mastitis (i.e., mastitis cases continuing longer than 28 days) can substantially affect the risk of transmission of intramammary infections (IMI) and total milk production losses. Insights into the impact of chronic mastitis on production and farm economics are needed to guide chronic mastitis decision-making. We aimed to estimate the costs of chronic mastitis with a Monte Carlo simulation model in which the costs of chronic mastitis were estimated as part of the total mastitis costs. The model simulated milk yields, IMI dynamics, somatic cell count (SCC), and pregnancy status on an average Dutch dairy farm with 100 cow places over 9 years. The model was parameterized using information from the literature and actual sensor data from automatic milking system (AMS) farms. The daily subclinical milk production losses were modeled using a generalized additive model and sensor data. Transmission of IMI was modeled as well. The model results indicated median total costs of mastitis of € 230 per generic IMI case (i.e., a weighted average of all pathogens). The most substantial cost factors were the extra mastitis cases due to transmission, culling, and milk production losses. Other significant costs originated from dry cow treatments and diverted milk. The model also indicated median total costs due to chronic mastitis of € 118 (51 % of the total mastitis costs). The share of chronic mastitis relative to the total mastitis costs was substantial. Transmission of contagious bacteria had the largest share among the chronic mastitis costs (51 % of the costs of chronic cases). The large share of chronic mastitis costs in the total mastitis costs indicates the economic importance of these mastitis cases. The results of the study point to the need for future research to focus on chronic mastitis and reducing its presence on the AMS dairy farm.

Although most of the losses due to mastitis per case in dairy production are estimated to be caused by clinical cases, subclinical cases, especially chronic, can also be problematic due to milk production losses and the risk of transmission of pathogens. Knowing which subclinical mastitis cases will become chronic at an early stage would be helpful in intervening in these cases. Automatic milking systems (AMS) can collect data on mastitis indicators such as conductivity, Somatic cell count (SCC), and blood in the milk for each milking. The aim of this study was to develop a sensor-based prediction model using SCC, conductivity, blood in the milk, parity, milk diversion, time interval between milkings, milk yield and DIM that forecasts the chronicity in subclinical mastitis cases after an initial increase in SCC. We used sensor data from 14 European and North American dairy farms (with herd sizes of lactating cows ranging from 55 to 638 cows and herd mean parities between 2.00 and 3.19) with an AMS and an online cell counter, measuring SCC. Typically, a threshold of 200,000 SCC/ml has been used to distinguish cows with subclinical mastitis from healthy cows. We used gradient-boosting trees and sensor data to forecast whether the SCC would decrease structurally below 200,000 SCC/ml in 50 days after the day at which the prediction was performed. Data from 30 and 15 days prior to the day where the forecast was made, was used. The model was trained on data from seven randomly selected dairy farms from the dataset and the data of the remaining seven dairy farms were used to estimate the predictive performance. These results were compared with two approaches that simulate how farmers would diagnose chronic mastitis with a simple prediction rule based on close-to-daily SCC (frequent sampling approach), and on less frequent monthly SCC (monthly sampling approach). We used accuracy, Matthew’s correlation coefficient (MCC), and Area under the Curve (AUC) as metrics to assess the forecasting performance of the chronic mastitis prediction model. On average, the forecast model, using 30 days of sensor data prior to the day of prediction, outperformed the approaches according to the accuracy (chronic mastitis prediction model: 0.888, frequent sampling approach: 0.848, and monthly sampling approach: 0.865), MCC (chronic mastitis prediction model: 0.712, frequent sampling approach: 0.630, and monthly sampling approach: 0.552), and AUC metrics (chronic mastitis prediction model: 0.964 and frequent sampling approach: 0.941) metrics. The results also indicate that shortening the input requirement from 30 days of prior sensor data to 15 days has a limited effect on the performance of the model. Overall, this study shows that it is possible with a high accuracy to predict the future chronic mastitis status using past sensor data and machine learning models.

Although it is still most common to rear dairy calves separately from adult cattle, the interest in pro-longed contact between dairy calves and lactating cows during early life is increasing. Previous research has documented positive effects of cow-calf contact (CCC) on for example early calf growth and udder health of suckled cows, but also negative effects such as increased separation distress and reduced weight gains after weaning. The aim of this study was to use information from European farms with prolonged cow-calf contact to identify innovative solutions to common challenges for CCC farms. Commercial dairy farms that kept calves with adult lactating cows for seven days or more after birth were invited to participate, and interviews were performed with 104 farmers from six countries. During interviews, information about farm management, calf rearing, farmers' perception of animal health on their farm, and farmers' drivers and barriers for implementing CCC were collected. We found that CCC was practised in a large variety of housing and management systems, and that calves could be reared together with their dam, with foster cows, or using a combination of the two. The contact period varied considerably (7-305 days) between farms and about 25% of the farms manually milk fed the calves during parts of the milk feeding period. Daily contact time varied between farms, from 30 minutes per day to permanent contact except at milking. Behaviours indicative of separation distress, most commonly vocalisation in cows and calves, were reported by 87% of the farmers. Strategies to alleviate separation distress, for example simultaneous gradual weaning and separation, were used on some farms. Building constraints were most often mentioned as a barrier for implementing CCC. Our findings suggest that CCC is practised in a variety of commonly used husbandry systems. Reported challenges were primarily related to weaning and separation, and to building constraints; these aspects should be areas of future research.@2022 The Authors. Published by Elsevier B.V. on behalf of The Animal Consortium. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Antimicrobial resistance (AMR) in bacteria in the livestock is a growing problem, partly due to inappropriate use of antimicrobial drugs. Antimicrobial use (AMU) occurs in Swedish dairy farming but is restricted to the treatment of sick animals based on prescription by a veterinary practitioner. Despite these strict rules, calves shedding antimicrobial resistant Enterobacteriaceae have been recorded both in dairy farms and in slaughterhouses. Yet, not much is known how these bacteria disseminate into the local environment around dairy farms. In this study, we collected samples from four animal sources (fecal samples from calves, birds and rodents, and whole flies) and two environmental sources (cow manure drains and manure pits). From the samples, Escherichia coli was isolated and antimicrobial susceptibility testing performed. A subset of isolates was whole genome sequenced to evaluate relatedness between sources and genomic determinants such as antimicrobial resistance genes (ARGs) and the presence of plasmids were assessed. We detected both ARGs, mobile genetic elements and low rates of AMR. In particular, we observed four potential instances of bacterial clonal sharing in two different animal sources. This demonstrates resistant E. coli dissemination potential within the dairy farm, between calves and scavenger animals (rodents and flies). AMR dissemination and the zoonotic AMR risk is generally low in countries with low and restricted AMU. However, we show that interspecies dissemination does occur, and in countries that have little to no AMU restrictions this risk could be under-estimated.

Reduction of milk yield is one of the principal components in the cost of mastitis. However, past research into the association between milk yield and mastitis indicators is limited. Past research has not been based on online or in-line daily measurements and has not fully explored nonlinearity and the thresholds at which milk yield starts to decrease. In dairy herds with automated milking systems equipped with sensors, mastitis indicators of individual cows are measured on an intraday frequency, which provides unprecedented avenues to explore such effects in detail. The aim of this observational study was primarily to investigate the nonlinear associations of lactate dehydrogenase (LDH), electrical conductivity (EC), and somatic cell count (SCC) with milk yield at various stages of lactation, parity, and mastitis chronicity status (i.e., whether the cow had SCC ≥200,000 SCC/mL for the last 28 d). We also investigated thresholds at which mastitis indicators (LDH, EC, and SCC) started to be negatively associated with milk yield. We used data from 21 automated milking system herds measuring EC and online SCC. Of these herds, 7 of the 21 additionally measured online LDH. We operationalized milk yield as milk synthesis rate in kilograms per hour. Applying a generalized additive model, we estimated the milk synthesis rate as a function of the 3 mastitis indicators for 3 different subgroups based on parity, stage of lactation, and mastitis chronicity. Partial dependence plots of the mastitis indicators were used to evaluate the milk synthesis rate to study if the milk synthesis rate was associated with mastitis indicators at a specific level. Results showed that milk synthesis rate decreased with increasing SCC, LDH, and EC, but in a nonlinear fashion. The thresholds at which milk synthesis rate started to decrease were 2.5 LnSCC (12,000 SCC/mL) to 3.75 LnSCC (43,000 SCC/mL), 0 to 1 LnLDH (1−2.7 U/L), and 5.0 to 6.0 mS/cm for EC. Additionally, another substantial decrease of milk synthesis rate was observed at thresholds of 5.625 LnSCC (277,000 SCC/mL) and 3 LnLDH (20 LDH U/L) but not for EC. Having chronic mastitis decreased milk synthesis rate in all models. The identified nonlinearities between mastitis indicators and milk synthesis rate should be incorporated in statistical models for more accurate estimations of milk loss due to mastitis.

In the Nordic countries, antimicrobial use in animals and the prevalence of antimicrobial resistance are among the lowest in Europe. The network "Nordic Vets Against AMR" organized a meeting in 2021, with key actors including representatives from universities, veterinary authorities and veterinary organizations in Finland, Norway and Sweden. This paper reflects the most important discussions on education, research, policy and future perspectives, including the experiences of these countries. It concludes that Nordic veterinarians are well placed to lead the way in the fight against antimicrobial resistance and that the sharing of experiences can support colleagues in other countries. Veterinary education must go hand in hand with research activities and continuously updated guidelines and legislation. There is also a need for postgraduate training on antimicrobial resistance and prudent antimicrobial use. The veterinary profession must, by any means necessary, protect the efficiency of antimicrobials for the sake of animal health, animal welfare and productivity, as well as public health. While restrictive use of antimicrobials is crucial, the ability of veterinarians to use this medical tool is also important for the sake of animal welfare and global food security.

The development of digital farming gives bovine mastitis research and management tools access to large datasets. However, the quality of registered data on clinical mastitis cases or treatments may be inadequate (e.g. due to missing records). In automatic milking systems, the decision to divert milk from the bulk milk tank during milking is registered (i.e. milk diversion indicator) for every milking and could potentially indicate a clinical mastitis case. This study accordingly estimated the diagnostic performance of a milk diversion indicator in relation to farmer-recorded clinical mastitis cases in the absence of a "gold standard". Data on milk diversion and farmer-reported clinical mastitis from 3,443 lactations in 13 herds were analyzed. Each cow lactation was split into 30-DIM periods in which it was registered whether milk was diverted and whether clinical mastitis was reported. One 30-DIM period was randomly sampled for each lactation and this was the unit of analysis, this procedure was repeated 300 times, resulting in 300 datasets to create autocorrelation-robust results during analysis. We used Bayesian latent class analysis to assess the diagnostic properties of milk diversion and farmerreported clinical status. We analyzed different episode lengths of milk diversion of 1 or more milk diversion days until 10 or more milk diversion days for two scenarios: farmers with poor-quality (51% sensitivity, 99% specificity) and high-quality (90% sensitivity, 99% specificity) mastitis registrations. The analysis was done for all 300 datasets. The results showed that for the scenario where the quality of clinical mastitis reporting was high, the sensitivity was similar for milk-diversion threshold durations of 1-4 days (0.843 to 0.793 versus 0.893). Specificity increased when the number of days of milk diversion increased and was >= 98% at a milk-diversion threshold durations of 8 or more consecutive milk diversion days. In the scenario where the quality of clinical mastitis reporting was low, the sensitivity of milk diversion and reported clinical mastitis cases was similar at milk-diversion threshold durations of 1-7 days (0.687 to 0.448 versus 0.503 to 0.504) while specificity exceeded the 98% at milk-diversion threshold durations of 7 or more consecutive milk diversion days. In both scenarios, a milk diversion threshold duration of 4-7 days achieved the most desirable combined sensitivity and specificity. This study concluded that milk diversion can be a valid alternative to farmer-reported clinical mastitis as it performs similarly in indicating actual clinical mastitis.

BACKGROUND AND AIMS:In Europe, the antimicrobial use (AMU) for food-producing animals has decreased rapidly. However, studies indicate that a too strict policy, with too restrictive AMU, is potentially problematic for veterinarians because it threatens animal welfare and creates tensions between farmers and veterinarians. The AMU in Sweden is among the lowest in Europe, and regulation of AMU in farm animals is strict. The aim of our study was to explore how Swedish veterinarians describe the relations between (1) being restrictive with antibiotics due to the risk of AMR and (2) concerns for animal welfare and/or the veterinarian-client relationship.METHODS:Semi-structured interviews with 21 veterinarians, working with dairy cattle, were performed. The transcripts were analysed, and a number of dominant patterns which recurred in all, or most of, the interviews were identified.RESULT:The interviewed veterinarians described AMR prevention and tackling the threat AMR poses towards public health, as central for their profession and as influencing their everyday practice and decisions on AMU. Importantly, veterinarians described accounting for AMR in everyday practice as fairly unproblematic, both in relation to animal welfare as well as in relation to farmers. The veterinarians generally perceived that they could treat animals with antibiotics when justified, and being restrictive with antibiotics was described as an expression of professional skill and not as challenging as animal welfare. Moreover, they stated that restrictive AMU seldom or never caused conflicts with farmers.CONCLUSION:Strict AMU policy and restrictive AMU do not necessarily put veterinarians in a problematic position where they are caught between conflicting demands and risks.