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.

Clinical mastitis, a prevalent production disease in the dairy industry, causes significant pain and swelling in dairy cows' udders. Although previous research highlights a symbiotic relationship between humans and animals, particularly in terms of health, this study investigates how animal health, specifically clinical mastitis, influences farmers' well-being. Acknowledging farmers' pivotal role in mitigating animal health problems, we examined the human-animal relationship by exploring how dairy cow health relates to the psychological well-being of dairy farmers. This was performed by investigating the connection between animal and farmer health and whether it is mediated by farmers' perceptions of mastitis as a production disease and their sense of control over the situation. For the current study, we combined and matched data from a large questionnaire study covering dairy farmer's well-being (n = 356) with data on dairy cow herd health. For statistical analyses we used the PROCESS macro (ver. 4.2) for serial multiple mediator analysis, an analysis that allows for the estimation of the effect of multiple mediators in a causal chain. We found that farmers' well-being is indirectly related to animal health when mediated through their illness perception and perceived self-efficacy, underscoring the importance of cultivating awareness and control over mastitis occurrences. For these estimations, we controlled for the effect of farm size, expected income from dairy production, marital status, and cohabitation status of the farmer, as well as age and gender. Our results indicate that maintaining healthy animals with minimal mastitis incidents, coupled with farmers' perceived self-efficacy, is positively related with farmer well-being.

Background: Cattle colonised by the zoonotic pathogen verotoxin-producing Escherichia coli of serotype O157 (VTEC O157) can shed high levels of the pathogen in their faeces. A suggested key for controlling VTEC O157 is preventing colonisation of individuals.Aim: In this study the role of individual super-shedders and factors related to susceptibility and environmental exposure in the transmission of VTEC O157 among dairy calves are explored.Methods: The association between sex, age, pen hygiene, pen type and stocking density and colonisation of individual calves, established by recto-anal mucosal swabs, on farms where pathogenic VTEC O157 had been confirmed was investigated. In a follow-up sampling, the consistency of previously identified risk factors and the role of shedding pen mates was assessed by studying the risk of new/re-colonisation.Results: The results suggest an important role of stocking density that decreases with age, possibly due to increased resistance to colonisation following exposure. However, previous colonisation did not influence the risk of being colonised in the second sampling. Super-shedders (shedding >103 colony forming units/g faeces) significantly increased the risk of colonisation in peers (OR = 10, CI 4.2–52). In addition, environmental factors associated with survival of the bacteria, affected risk.Conclusion: The results confirm the suggested importance of super-shedders but also emphasises the importance of considering the combined exposure from peers and the environment.

Background Piglets are born with limited stores of iron, and with an increasing number of live-born piglets, there may be a risk that the sows cannot provide enough iron to their offspring. The iron content in soil may not meet the demands of today’s piglet, born and reared in an outdoor setting. The study aimed to describe the blood haemoglobin (Hb) levels in pigs reared outdoors and to determine whether piglets have higher Hb levels at weaning when an iron supplement is administered intramuscularly at three days of age, as compared to pigs not given an iron supplement. The seasonal variation in Hb-levels was also to be investigated. The Hb concentration was analysed with a HemoCue 201 + Hb photometer. Results In total 56 litters (399 piglets) were included in the study and sampled at three days of age, while 378 piglets were sampled at weaning. The mean Hb level at three days of age was 91 g/L (48–154 g/L). In total 47% of the piglets had Hb levels < 90 g/L at three days of age. The mean Hb level at weaning was 127 g/L (76–176 g/L), with a lower level (122 g/L) in the group given the iron supplement than in the group not given an iron supplement (132 g/L). Only 1% of the piglets had Hb levels lower than 90 g/L at weaning. Results indicative of a seasonal effect on Hb levels at three days of age was demonstrated. Piglets born in spring had significantly lower Hb levels, and piglets born in autumn had significantly higher Hb levels. No seasonal effect could be demonstrated for Hb levels at day 33. Conclusions The results indicate that the natural uptake from the environment was sufficient, but that there was a seasonal effect on the Hb levels at three days of age. This indicates that there might be a need for different routines regarding iron supplementation in outdoor reared piglets depending on the climate and season.

Abstract High body weight (BW) in dogs has been associated with developmental as well as degenerative diseases, but the heritability of BW in dog breeds is largely unknown. The aim of the current study was to estimate heritability and genetic change (genetic trend) for BW in a range of dog breeds in Sweden. Body weight registrations from 19 dog breeds (with n ranging from 412 to 4,710) of varying body size, type and usage were collected from 2007 to 2016. The average BW of the breeds was 8 to 56 kg. The BW registrations were performed when the dogs were 12 to 24 mo of age (18 to 30 mo for one large-sized breed) in connection with an official radiographic screening program for hip dysplasia. Collected weight records were used to estimate heritability and genetic trends for BW. Several statistical models were used. The preliminary model included the fixed effects of breed (P < 0.001), sex (P < 0.001), year of screening (P < 0.001), litter size (P = 0.06), parity of the dam (P = 0.03) and linear regression on age at screening (P < 0.001), the latter five effects all nested within breed, and the random effects of litter and dam. Season of birth and the quadratic effect of age were also tested, but were not significant (P > 0.10). For the genetic analysis, various mixed linear models were tested within breed with different combinations of random effects; the most complex model included random effects of litter, direct additive, and maternal genetic effects, and maternal permanent environmental effects. The average heritability for BW over all 19 breeds was 51%, with a range of 35% to 70%, and the additive genetic coefficient of variance was around 9%. Maternal heritability was 5% to 9% and litter variance was below 10% with one exception (15% in Shetland Sheepdogs). For nine breeds, there was a genetic trend of increasing BW, whereas seven breeds had a genetic trend of decreasing BW. The largest absolute genetic change over a 10-yr period was around 0.6 kg or about 2% of the mean. In conclusion, given the small genetic changes in spite of the high heritability, it seems that there is generally a very weak selection, if any, for BW in the included dog breeds.

High body weight (BW), due to large size or excess body fat, has been associated with developmental and metabolic alterations, and degenerative diseases in dogs. Study objectives were to determine mean BW in young adult dogs of different breeds, including changes over a 10-year period. Body weight data from the official Swedish hip dysplasia screening program were used, including data from dogs screened at 1–2.5 years of age, in breeds with ≥ 15 individual observations/year during 2007–2016. Mean BW per breed and sex was established from 114 568 dogs representing 72 breeds. Estimates of breed BW showed significant change in 33 (45%) breeds over the 10-year period. Body weight increased in five breeds (2–14% change) and decreased in 26 breeds (1–8% change). In two breeds, BW increased in male and decreased in female dogs. This observational study provides extensive breed BW data on young adult dogs. The change in breed BW, noted in almost half of the breeds, could be due to changes either in size or in body fat mass. In certain breeds, the change in BW over time might have an impact on overall health. Studies with simultaneous evaluation of BW and body condition over time are warranted.

Mastitis control options (MCOs) are management actions that are adopted to prevent mastitis in dairy herds. In this study, the psychological constructs attitude, social norms and perceived behavioral control are used to explain farmers’ adoption of MCOs. So far, little research has used psychological constructs to explain adoption of MCOs. Based on recommendations by a Swedish dairy association (Växa) aimed at farmers, a total of 15 different management areas, representing MCOs for contagious and environmental bacteria, were used to characterize adoption behaviors. A total of 286 Swedish full-time farmers specializing in dairy production participated in the survey. Four different farmer groups were identified through a cluster analysis of similarities in how farmers adopted MCOs together with data on bulk milk somatic cell count and subjectively evaluated somatic cell counts on the farms. Regression analyses were performed to test whether the psychological constructs could explain differences in adoption across the MCO groups. Results revealed that farmers’ decisions about which set of mastitis control options to adopt as preventive actions were explained by the farmers’ perceived behavioral control of the situation and by differences in subjective norm. The attitude construct did not contribute to predicting the adoption of mastitis control options. Results suggest that work aimed at implementing MCOs should be complemented by programs specifically designed to improve the ability of farmers to use and/or combine MCOs to both alleviate and prevent mastitis. They also suggest that there is little to gain from programs aimed at fostering attitudes to prevent mastitis. We interpret the findings as indicating a need to strengthen perceived behavioral control as well as subjective norms among Swedish farmers’ regarding their preventive work with mastitis. Understanding how to affect farmers’ behavior, and thus reducing and controlling mastitis, will have positive effects on animal health and welfare in general.

Background Accurate and reliable assessment of clinician integrity in the delivery of empirically supported treatments is critical to effective research and training interventions. Assessment of clinician integrity can be performed through recording simulated (SI) or real-life (RL) consultations, yet research examining the equivalence of these data is in its infancy. To explore the strength of integrity assessment between SI and RL samples in Motivational Interviewing (MI) consultations, this article examines whether Motivational Interviewing Treatment Integrity (MITI) assessments differ between SI and RL consultations and reviews the predictive validity of SI and RL MI skills categorisations for RL client response language. Methods This study first compared MITI coding obtained in SI and RL consultations for 36 veterinary clinicians. Multilevel models of 10 MITI behaviour counts and four MITI global scores were run using MLwiN 3.02 to assess if a significant difference existed between SI and RL MITI data, with consultation within clinician within cohort (A and B) as nested random effects. Second, we investigated the effect of SI and RL MI skills groupings on rate of RL client response talk using three multivariable regression models. Two Poisson regression models, with random intercepts for farm and veterinarian and offset for number of minutes of the recordings, were estimated in the statistical software R using the package glmmTMB for the two response variables Change Talk and Sustain Talk. A logistic regression model, with the same random intercepts, with the response variable Proportion Change Talk was also estimated using the same package. Results Veterinary clinicians were less MI consistent in RL consultations, evidenced through significantly lower global MITI Cultivating Change Talk (p < 0.001), Partnership (p < 0.001) and Empathy (p = 0.003) measures. Despite lower objective MI skills groupings in RL consultations, ranking order of veterinary clinicians by MI skills was similar between contexts. The predictive validity of SI and RL MI skills groupings for RL client Change Talk was therefore similar, with significantly more RL client Change Talk associated with veterinarians categorised in the highest grouping (‘moderate’) in both SI (p = 0.01) and RL (p = 0.02) compared to untrained veterinarians in each respective context. Conclusions Findings suggest SI and RL data may not be interchangeable. Whilst both data offer useful insights for specific research and training purposes, differing contextual MI skills thresholds may offer a more equitable assessment of clinician RL client-facing MI integrity. Further research is needed to explore the applicability of these findings across health contexts.

BACKGROUND:Cranial cruciate ligament disease (CCLD) is common in dogs, but studies on the long-term treatment outcome are scarce.METHODS:The long-term outcome in a cohort of 71 dogs with CCLD treated with tibial plateau levelling osteotomy (TPLO, n = 18), tibial tuberosity advancement (TTA, n = 23) or lateral fabellotibial suture (LFS, n = 30) was evaluated using the canine orthopaedic index.RESULTS:The risk of stiffness and lameness was increased in dogs treated with TPLO (stiffness: incidence rate ratio [IRR] 1.33, p = 0.015; lameness: IRR 1.34, p = 0.020) or TTA (stiffness: IRR 1.26, p = 0.035; lameness: IRR 1.31, p = 0.026) when compared to LFS at a median follow-up time of 4.6 years.LIMITATIONS:No follow-up veterinary examination was performed. Data were collected from only two university animal hospitals, and thus, a referral bias towards more complicated cases is possible, which may limit the generalisability of the results.CONCLUSION:Clinicians can use the results to inform dog owners about the expected long-term outcome in dogs with CCLD.

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.

We estimate the relationship between farm animal welfare (FAW) efforts taken by beef farmers and the economic performance of beef farms by using farm accounting data from the Swedish Farm Economic Survey matched with survey data on farm management practices. To this end, we perform a two-step analysis. First, an item response theory (IRT) model estimates the latent FAW effort on farms. FAW effort likely depends on a host of complementary FAW-improving strategies, and the IRT model combines the considered strategies into a unidimensional scale. We take this to represent on-farm FAW effort. Second, we use instrumental variable regressions to estimate the relationship between FAW effort and multiple measures of farm economic performance. We find that higher FAW effort scores have no effect on margins and costs. However, higher FAW effort scores are associated with lower farm sales. Findings suggest that policies (such as targeted label for high FAW) that increase farm revenue as well as incentivize the uptake of FAW-improvement practices may be able to compensate farmers for their FAW effort.

Mastitis control options (MCOs) are management actions that are adopted to prevent mastitis in dairy herds. In this study, the psychological constructs attitude, subjective norms and perceived behavioral control are used to explain farmers' adoption of MCOs. So far, little research has used psychological constructs to explain adoption of MCOs. Based on recommendations by a Swedish dairy association (Va center dot xa) aimed at farmers, a total of 15 different management areas, representing MCOs for contagious and environmental bacteria, were used to characterize adoption behaviors. A total of 286 Swedish full-time farmers specializing in dairy production participated in the survey. Four different farmer groups were identified through a cluster analysis of similarities in how farmers adopted MCOs together with data on bulk milk somatic cell count and subjectively evaluated somatic cell counts on the farms. Regression analyses were performed to test whether the psychological constructs could explain differences in adoption across the MCO groups. Results revealed that farmers' decisions about which set of mastitis control options to adopt as preventive actions were explained by the farmers' perceived behavioral control of the situation and by differences in subjective norm. The attitude construct did not contribute to predicting the adoption of mastitis control options. Results suggest that work aimed at implementing MCOs should be complemented by programs specifically designed to improve the ability of farmers to use and/or combine MCOs to both alleviate and prevent mastitis. They also suggest that there is little to gain from programs aimed at fostering attitudes to prevent mastitis. We interpret the findings as indicating a need to strengthen perceived behavioral control as well as subjective norms among Swedish farmers' regarding their preventive work with mastitis. Understanding how to affect farmers' behavior, and thus reducing and controlling mastitis, will have positive effects on animal health and welfare in general.

Mastitis is the most prevalent and costly production disease in the dairy industry, but udder health advice that helps one herd might not be beneficial for another because of "local truths". It is therefore important to identify what mastitis control options may work in a specific herd in the conditions specific to the herd. We evaluated whether the Evolutionary Operation (EVOP) methodology could be used as a management tool to identify mastitis control options to improve udder health in dairy herds. Within an EVOP framework we conducted sequences of experiments, on each of two dairy farms in Sweden. The experiments covered interventions within 1) hygiene in cubicles, 2) milking routines, and 3) dry-off procedures. Automatically recorded somatic cell counts (SCCs) in milk were used as the response variable. The impact of the interventions on SCC was evaluated with multivariate dynamic linear models. Farmer and staff satisfaction was assessed through interviews. The EVOP methodology was successfully applied, and the farmers appreciated it. We observed herd-specific variation in the effect of the interventions, indicating that EVOP would be a feasible approach to tailor mastitis control options to individual herds. Our results indicate that the EVOP methodology could be a tool to identify and evaluate health management strategies on dairy farms.

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.

The purpose of this study was to compare animal health in compost-bedded pack (CBP) and cubicle housing (CH) systems using data from dairy herd improvement associations. Thirty-two commercial dairy farms located in Austria, Germany, Italy, The Netherlands, Slovenia, and Sweden were included in the study. A matching design (pairing CBP and CH within country) according to herd selection criteria was used. We explored the following health indicators: somatic cell counts (SCC), high SCC, new high SCC, ketosis risk, prolonged calving intervals, dystocia, and stillbirth. Traits for culling and culling-related issues, such as length of life and length of productive life, were also included. We used multivariable (mixed) linear and logistic regression models to evaluate differences between the systems. Udder health, as measured by SCC, was inferior in CBP, although the geometric means were low in both systems. The incidence of stillbirths was higher in CBP, while prolonged calving intervals were fewer, indicating that there were fewer reproductive disorders. There were no differences in longevity between the systems, although CBP had lower proportions of first calvers. Overall, we conclude that there were few and minor differences in health and longevity between the CBP and CH systems in the European context.

Enteritis is the major cause of mortality in neonatal calves. Diagnostic work to detect the pathogens involved and identification of risk factors for such infections are imperative to improve calf health. Bovine norovirus (BNoV) and nebovirus prevalence was investigated using RT-PCR in 50 dairy herds in five geographic regions of Sweden. BNoV and nebovirus were found to be common infections in young dairy calves. BNoV was detected in 20% of 250 calves in 48% of the herds. Nebovirus was detected in 5% of the calves in 16% of the herds. Both infections were present in three herds (6%). BNoV-infected calves were younger (median age 7 days) than nebovirus-infected calves (median age 21 days). These infections were not detected in adult cows and young stock over 6 months of age tested in selected herds. Risk factors identified for BNoV infection were a high number of preweaned calves present at the time of sampling, colostrum uptake by suckling the dam only, calf kept in a single pen, and geographic location of herd, while no risk factors for nebovirus infection were identified in the multivariable analysis. Univariable analysis suggested risk factors for nebovirus infection to be geographic location and early separation from the dam.

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.

This study aims to identify the effects of temperature on dairy production and the heat tolerance of different dairy breeds under heat stress. Using farm and animal-level data from 1435 dairy farms throughout Sweden for 4 years (from 2016 to 2019), we find that a 7-day average of daily maximum temperatures above ~ 20 ºC is associated with sharp declines in milk production. We then estimate the farm-level loss in contribution margin for a typical Swedish dairy farm for the year 2018, which consisted of long-lasting heatwaves and extended summer temperatures. We also estimate that, on average, there are no differences in the impact of heatwaves on milk losses for different dairy breeds but that there exists a trade-off between genetic milk production potential and heat tolerance of a dairy cow. The magnitude of this productivity-tolerance trade-off may differ across breeds, suggesting that the high-production potential animals of certain breeds may be less sensitive to heat stress. These findings have important implications in terms of adapting to heat stress, investing in mitigation measures, and development of future breeds that can ameliorate the current trade-off between production capacity of a cow and its heat tolerance.

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.

Communication has been identified as one constraint for cattle veterinarians to act as proactive health consultants. Motivational Interviewing (MI), an evidence-based client-centered communication methodology, may therefore be a useful tool in veterinary herd health management (VHHM). The aim of this exploratory study was to investigate associations between training in MI and different measures of performance in VHHM. MI skills of 36 Swedish cattle veterinarians randomly assigned to two groups -MI veterinarians (n = 18) who had received six-months training in MI and control veterinarians (n = 18) who were not trained -were assessed using the MI Treatment Integrity coding system. Skills were categorized as untrained, trained_poor, trained_near moderate and trained_moderate. Veterinarians each visited two to six cattle farms for VHHM consultations and revisited the same farms three to six months later to document implementation of recommendations. A gamma model and logistic or ordered logistic regression models were used to evaluate associations between MI training and performance measured as: a) proportion of consultations resulting in written herd health plans, b) proportion of recommended measures fully or partially implemented, c) Likert scores of different estimates of client satisfaction and d) total time during 6 months allocated to VHHM visits on cattle farms. We found no evidence of any significant effects of MI training on the eight performance variables analyzed. However, a pattern of numerically higher values (better performance) in trained veterinarians with poor or moderate MI skills than in untrained veterinarians was observed in most variables. Clients were highly satisfied with veterinarians' attitude, competence and time efficiency. Farms implemented a median of 66.7% (interquartile range: 50-100) of the measures partially or fully. Veterinarians allocated little time to VHHM visits (median: 2.2; interquartile range: 0.65-4.1 h per week of full-time work within cattle). Veterinarians with moderate skills spent 2.14 times more time on VHHM visits than untrained veterinarians, but the confidence interval was wide (0.88-5.21). The pattern of numerically higher values in trained veterinarians supported findings from other studies in the same project indicating a positive effect of MI training on VHHM. Our observations suggest a considerable potential to increase veterinarians' engagement in VHHM.