Application of Epidemiological Methods in a Large-Scale Cross-Sectional Study in 765 German Dairy Herds-Lessons Learned.

From 2016 to 2020, the "PraeRi" study, conducted by three German veterinary universities, was aimed at enhancing animal health and welfare in dairy farms. With 765 dairy farms visited and 101,307 animals examined, this study provided a basis for improving animal health and welfare. The study population comprised three different regions representing a broad variety of characteristics. To ensure representative estimates, a sample size of 250 farms was determined for each region, employing a stratified sampling plan based on farm size. According to the information provided by the farmers, the most commonly occurring disease in their herds was mastitis without general disorder (14.2% to 16.3% of the herd-depending on the region). For most disorders, prevalence data were lowest for the region South compared with the two remaining regions. Multivariable regression analyses were performed to identify risk factors for various target variables, and the results were communicated through individual reports and benchmarking flyers to participating farmers. The authors encountered challenges in management and communication due to the project's size in terms of personnel, data, and farms examined. Harmonizing data management and hypothesis testing across all involved parties added complexity.

Comparison of plasma substance P concentrations in the blood of healthy male and female German Simmental calves.

BACKGROUND: The recognition of pain is a major problem in cattle, as they are stoic animals which strongly mask their pain. Among objective parameters to assess pain in cattle is substance P (SP), a neurotransmitter which is involved in the pain pathways. Research about SP concentration in calves focus on painful procedures, such as castration and dehorning. Basic research work is lacking; evaluation of SP concentrations in healthy calves and possible differences between sexes have not been published yet. The objectives of this study were to (1) describe SP concentrations in healthy male and female calves of the German Simmental breed to establish benchmarks of orientation, (2) compare SP concentrations between male and female calves, and (3) assess differences in SP concentrations between calves and adult cows. A total of 44 male and 49 female calves aged 14 to 21 days (17.1 ± 2.2 days) were included in this study. Blood samples were taken at 06:00 a.m. from the jugular vein, followed by a clinical examination. SP concentrations were analyzed using a commercial ELISA kit. Differences in SP concentrations according to laboratory parameters, and correlation of SP concentrations with different parameters were assessed. RESULTS: Median SP concentrations in the blood plasma were 516 pg/ml (Interquartile Range 320 pg/ml, range 229-1615 pg/ml) in calves. Median SP concentrations differed significantly between male and female calves (554 pg/ml for male, and 489 pg/ml for female calves, respectively). There was no significant difference in animals with laboratory findings within reference ranges and those with mild deviations from reference ranges. There was a positive correlation between SP concentrations and leucocyte count, which was significant. SP concentrations were significantly lower in calves compared with a dataset of adult cows, which has been published previously. CONCLUSION: Due to the high interindividual differences in SP concentrations, it is hard to establish benchmarks for orientation. Sex has a significant influence on SP concentrations. Research work should preferably be done in animals of the same sex. Also, animals should be within the same age range (adults or calves), as age seems to have an influence on SP concentrations.

[Homemade herbal remedies - tradition with practical relevance]. / Pflanzliche bäuerliche Hausmittel ­ Tradition mit Praxisrelevanz.

OBJECTIVE: The preparation of homemade herbal remedies has always been practiced by animal keepers and is still employed in farm animals today. In order to document this practice, an ethnoveterinary study was conducted in Bavaria in 2018-2021. MATERIAL AND METHOD: The farmers were interviewed on site and the reported recipes were documented in detail and, where possible, also carried out during the interviews. The plant parts used were weighed using a laboratory balance in order to be able to calculate a daily dose per animal or the concentration in the end product for as many of these traditional use reports (UR) as possible. RESULTS: A total of 716 recipes for 884 UR were named in the 77 interviews by the participating farmers. Two thirds (69%) of the formulations mentioned consisted of one or more medicinal plants and 31% dealt with other natural home remedies (honey, vinegar, etc.). Overall, the farmers surveyed preferred the use of single plants in their formulations. Most UR were for cattle (77% of all reports). These traditional remedies are most often used in Bavarian stables for the treatment and prophylaxis of gastrointestinal diseases and metabolic disorders. Furthermore, there was a high correspondence of the medicinal plants used with described UR from two historical reference books. The study participants used their homemade herbal remedies with a high degree of satisfaction and thereby act within the scope of their own responsibility as farmers. CONCLUSION AND CLINICAL RELEVANCE: This traditional knowledge of herbal preparations containing active ingredients, which has been passed on for generations, may also be a good starting point for a phytotherapeutic supplement in the treatment of farm animals in veterinary practice. Pharmaceutical and feed law framework conditions must be adhered to.

In-herd prevalence of Fasciola hepatica and Calicophoron / Paramphistomum spp. infections in German dairy cows with comparison of two coproscopical methods and establishment of real-time pyrosequencing for rumen fluke species differentiation.

Infections with liver and rumen flukes are among the most frequent parasitic diseases in cattle worldwide. In Europe, the predominant liver fluke species is Fasciola hepatica, and the recently rapidly spreading rumen flukes are mostly Calicophoron daubneyi and occasionally Paramphistomum leydeni. In this study, 1638 faecal samples from individual dairy cows from 24 northern and 18 southern German farms as well as one central German farm, all preselected for potential F. hepatica infection, were examined to determine in-herd prevalences of liver and rumen fluke infections. Furthermore, individual faecal egg counts (FECs) were determined in the northern and central German cows. On farms with patent F. hepatica infections, the mean in-herd prevalence was 15.8% in northern Germany, 41.6% in southern Germany and 14.0% in the central German farm. Rumen fluke infections resulted in high in-herd prevalences in all regions with a mean prevalence of 46.0% in northern, 48.4% in southern and 40.0% in central Germany. Individual FECs varied between 0.1 and 4.1 (mean 0.4) eggs per gram faeces (EPG) for F. hepatica and between 0.1 and 292.4 (mean 16.9) EPG for rumen flukes. Mean in-herd prevalence and mean FECs did not differ significantly between mono- and coinfected farms for either fluke species. Comparison of the classical sedimentation technique and the Flukefinder® method on a subset of 500 faecal samples revealed a similar number of positive samples, however, Flukefinder® mean FECs were three to four times higher for liver and rumen fluke eggs, respectively, with an increasing gap between EPG levels with rising egg counts. Fluke egg size measurement confirmed P. leydeni eggs on average to be larger in length and width (161.0 µm x 87.1 µm) than those of C. daubneyi (141.8 µm x 72.9 µm). However, due to overlap of measurements, morphological species identification based on egg size proved unreliable. For accurate identification, a real-time pyrosequencing approach was established, offering the advantage over classical Sanger sequencing of unambiguously identifying rumen fluke mixed species infections. Real-time pyrosequencing confirmed C. daubneyi (78.1% [50/64]) as the predominant rumen fluke species in Germany, while P. leydeni was detected in 12.5% (8/64) of sampled cows. A total of 9.4% (6/64) cows were infected with both C. daubneyi and P. leydeni, representing the first finding of a mixed infection in domestic ruminants in Europe to date.

Random forest classification as a tool in epidemiological modelling: Identification of farm-specific characteristics relevant for the occurrence of Fasciola hepatica on German dairy farms.

Fasciola hepatica is an internal parasite of both human and veterinary relevance. In order to control fasciolosis, a multitude of attempts to predict the risk of infection such as risk maps or forecasting models have been developed. These attempts mainly focused on the influence of geo-climatic and meteorological features. Predicting bovine fasciolosis on farm level taking into account farm-specific settings yet remains challenging. In the present study, a new methodology for this purpose, a data-driven machine learning approach using a random forest classification algorithm was applied to a cross-sectional data set of farm characteristics, management regimes, and farmer aspects within two structurally different dairying regions in Germany in order to identify factors relevant for the occurrence of F. hepatica that could predict farm-level bulk tank milk positivity. The resulting models identified farm-specific key aspects in regard to the presence of F. hepatica. In study region North, farm-level production parameters (farm-level milk yield, farm-level milk fat, farm-level milk protein), leg hygiene, body condition (prevalence of overconditioned and underconditioned cows, respectively) and pasture access were identified as features relevant in regard to farm-level F. hepatica positivity. In study region South, pasture access together with farm-level lameness prevalence, farm-level prevalence of hock lesions, herd size, parity, and farm-level milk fat appeared to be important covariates. The stratification of the analysis by study region allows for the extrapolation of the results to similar settings of dairy husbandry. The local, region-specific modelling of F. hepatica presence in this work contributes to the understanding of on-farm aspects of F. hepatica appearance. The applied technique represents a novel approach in this context to model epidemiological data on fasciolosis which allows for the identification of farms at risk and together with additional findings in regard to the epidemiology of fasciolosis, can facilitate risk assessment and deepen our understanding of on-farm drivers of the occurrence of F. hepatica.

Associations of production characteristics with the on-farm presence of Fasciola hepatica in dairy cows vary across production levels and indicate differences between breeds.

Fasciola hepatica is one of the economically most important endoparasites in cattle production. The aim of the present work was to evaluate the relevance of production level on the associations of on-farm presence of F. hepatica with farm-level milk yield, milk fat, and milk protein in Holstein cows, a specialised dairy breed, and in Simmental cows, a dual purpose breed. Furthermore, we investigated whether differential associations were present depending on breed. Data from 560 dairy farms across Germany housing 93,672 cows were analysed. The presence of F. hepatica antibodies was determined via ELISA on bulk tank milk samples. Quantile regression was applied to model the median difference in milk yield, milk fat, and milk protein depending on the interaction of breed and fluke occurrence. Whereas a reduction in milk yield (-1,206 kg, p < 0.001), milk fat (-22.9 kg, p = 0.001), and milk protein (-41.6 kg, p <0.001) was evident on F. hepatica positive German Holstein farms, only milk fat (-33.8 kg, p = 0.01) and milk protein (-22.6 kg, p = 0.03) were affected on F. hepatica positive German Simmental farms. Subsequently, production traits were modelled within each of the two breeds for low, medium, and high producing farms in the presence of F. hepatica antibodies and of confounders. On Holstein farms, the presence of F. hepatica seropositivity was associated with lower production, while on German Simmental farms such an association was less evident. This work demonstrates that production level is relevant when assessing the associations between the exposure to F. hepatica with production characteristics. Moreover, both models indicate a breed dependence. This could point towards a differential F. hepatica resilience of specialised dairy breeds in comparison with dual purpose breeds.

Evaluation of Substance P concentrations in the blood plasma of jugular and tail vein of healthy German Simmental cows.

BACKGROUND: Cattle strongly mask their pain, making the recognition and assessment of pain difficult. Different subjective and objective parameters to assess pain have been described. Substance P (SP), which is a neurotransmitter, is used to objectively evaluate nociception in cattle. However, SP concentrations have mainly been described in diseased animals, or animals subjected to painful procedures. To this day, no evaluation of SP in healthy adult cattle has been published. The objectives of this pilot study were to 1) assess the SP concentrations in healthy adult German Simmental cattle in the blood plasma, 2) compare the concentrations between the blood of the jugular and the tail vein, and 3) assess the concentrations in the blood of the tail vein every 6 h over a period of 24 h. A total of 52 healthy cattle of the German Simmental breed were included in this study. Animals were 5.0 ± 1.3 (mean ± SD) years old and between 117 and 239 (175.0 ± 34.1) days in milk. Blood samples were taken from the jugular vein (BJV, 07:45 a.m.) and the tail vein (TV1, 08:00 a.m.) each. Additional blood samples were taken every 6 h over the course of 24 h from the tail vein (TV2 - TV5). SP concentrations were analyzed using a commercial ELISA kit. RESULTS: Mean (± SD) and median SP concentrations were 1.087 ± 436 pg/ml and 984 pg/ml for BJV (range 502 - 2,337 pg/ml), and 920 ± 402 pg/ml and 818 pg/ml for TV1 (range 192 - 2,531 pg/ml), respectively. There was a significantly positive correlation between SP concentrations of BJV and TV1. SP concentrations between BJV and TV1 were significantly different, as were SP concentrations in the tail vein between sampling times over the course of 24 h. CONCLUSIONS: The results of this study show that blood samples to assess SP concentrations in cattle can be taken from the jugular as well as from the tail vein. There are high variations in concentrations between animals, and it is hard to define reference ranges for SP in healthy animals. Repeated blood samples should not be taken by repeated punctation of a vein but by use of a jugular vein catheter, which is a major limitation of the present study.

Relationship of body condition and milk parameters during lactation in Simmental cows in Bavaria, Germany.

In dairy cows the body condition forms a reflection of the energy reserves of the organism. Health, welfare and productivity of dairy cows are strongly associated with changes in body condition. As lactation puts substantial demands on the metabolism of dairy cows, farm management aims at avoiding either a deficient body condition or a substantial loss of body condition within a short period of time. A body condition higher or lower than recommended (over- and underconditioning in the following) compromises dairy cow productivity. While the body condition of Holstein Friesian cows has been thoroughly explored, few is known about the consequences of deviations from a target body condition for health and productivity of cows from other breeds. This study explores the percentage of over- and underconditioned cows at different days post partum [dpp] and their association with production parameters i.e., milk yield, milk fat and milk protein content of Simmental cows on Bavarian farms, categorized by parity (primi- or multiparous). Our study displays that in Simmental cows, overconditioning is more prevalent than underconditioning. While the middle of lactation (dpp = 100-199) resulted in higher percentage of overconditioning, the dry period (dpp = < 0 & > 299) indicated a higher percentage of underconditioned cows. The dry period and the middle of lactation are therefore the most challenging lactation stages for Simmental cows. We found milk protein content to have the strongest association with over- and underconditioning in Simmental cows. The probability of overconditioning was higher with higher milk protein content for every lactation stage and the probability of underconditioning was lower with higher milk protein content in every lactation stage. This study provides a theoretical basis for potential improvements in stockbreeding, which, if implemented, could improve not only the milk yield of Simmental dairy cows, but also their health and welfare.

Multinomial logistic regression based on neural networks reveals inherent differences among dairy farms depending on the differential exposure to Fasciola hepatica and Ostertagia ostertagi.

Fasciola hepatica and Ostertagia ostertagi are cattle parasites with worldwide relevance for economic outcome as well as animal health and welfare. The on-farm exposure of cattle to both parasites is a function of host-associated, intrinsic, as well as environmental and farm-specific, extrinsic, factors. Even though knowledge on the biology of both parasites exists, sophisticated and innovative modelling approaches can help to deepen our understanding of key aspects fostering the exposure of dairy cows to these pathogens. In the present study, multiple multinomial logistic regression models were fitted via neural networks to describe the differences among farms where cattle were not exposed to either F. hepatica or O. ostertagi, to one parasite, or to both, respectively. Farm-specific production and management characteristics were used as covariates to portray these differences. This elucidated inherent farm characteristics associated with parasite exposure. In both studied regions, pasture access for cows, farm-level milk yield, and lameness prevalence were identified as relevant factors. In region 'South', adherence to organic farming principles was a further covariate of importance. In region 'North', the prevalence of cows with a low body condition score, herd size, hock lesion prevalence, farm-level somatic cell count, and study year appeared to be of relevance. The present study broadens our understanding of the complex epidemiological scenarios that could predict differential farm-level parasite status. The analyses have revealed the importance of awareness of dissimilarities between farms in regard to the differential exposure to F. hepatica and O. ostertagi. This provides solid evidence that dynamics and relevant factors differ depending on whether or not cows are exposed to F. hepatica, O. ostertagi, or to both.

Understanding the uptake of diagnostics for sustainable gastrointestinal nematode control by European dairy cattle farmers: a multi-country cross-sectional study.

To mitigate emerging anthelmintic resistance (AR) in cattle, sustainable gastrointestinal nematode control strategies should be adopted. A multi-centre study was set up to understand the factors affecting European dairy cattle farmers' adoption of diagnostics and to gauge for differences between regions. The data were collected through a multi-lingual survey by participating countries of the European Co-operation in Science and Technology (COST) action COMbatting Anthelmintic Resistance in ruminants (COMBAR). Four countries provided sufficient data to be included in the data analysis: Norway, Italy, Germany and Austria. Three models were estimated and validated through structural equation modelling. Norway, along with Germany and Austria (pooled dataset) showed similar trends that align with previous studies. AR risk perception had no influence on the adoption intention of diagnostics, a positive influence was found for attitude towards diagnostics and subjective norms (i.e., perceived opinion of others), and a negative influence of attitudes towards anthelminthics. Additionally, routine (i.e., perception of the current treatment) had an indirect effect on adoption intention through attitudes. Italy's data deviated from these findings, presenting a positive effect of the perceived severity of AR, and perceived behavioural control (i.e., perceived ability to perform a specific behaviour) on adoption intention of diagnostics. Finally, Norway's data set allowed for inclusion of a measurement of current behaviour in the model, identifying a direct positive effect of the perceived actual behaviour of other farmers on their own behaviour.

Title: Comprendre l'adoption des diagnostics pour le contrôle durable des nématodes gastro-intestinaux par les producteurs laitiers européens : une étude transversale multi-pays. Abstract: Pour atténuer la résistance émergente aux anthelminthiques (RA) chez les bovins, des stratégies durables de contrôle des nématodes gastro-intestinaux devraient être adoptées. Une étude multicentrique a été réalisée pour comprendre les facteurs affectant l'adoption des diagnostics par les éleveurs de bovins laitiers européens, et pour évaluer les différences entre les régions. Les données ont été recueillies au moyen d'une enquête multilingue menée par les pays participants à l'action de European Co-operation in Science and Technology (COST) COMbatting Anthelmintic Resistance in ruminants (COMBAR). Quatre pays ont collecté suffisamment de données pour être inclus dans l'analyse statistique : la Norvège, l'Italie, l'Allemagne et l'Autriche. Trois modèles ont été estimés et validés par modélisation d'équations structurelles. La Norvège, et d'autre part l'Allemagne et l'Autriche (données regroupées) ont montré des tendances similaires qui correspondent aux études précédentes. La perception de la RA n'avait aucune influence sur l'intention d'adoption des diagnostics, une influence positive a été trouvée pour l'attitude envers les diagnostics et les normes subjectives (c'est-à-dire l'opinion perçue des autres), et une influence négative des attitudes envers les anthelminthiques. De plus, la routine (c'est-à-dire la perception du traitement actuel) a eu un effet indirect sur l'intention d'adoption par le biais des attitudes. Les données de l'Italie s'écartaient des résultats précédents, présentant un effet positif de la gravité perçue du risque de la RA, et du contrôle comportemental perçu (c'est-à-dire la capacité perçue à adopter un comportement spécifique) sur l'intention d'adoption de diagnostic. Enfin, l'ensemble de données de la Norvège a permis d'inclure une mesure du comportement actuel dans le modèle, identifiant un effet positif direct du comportement réel perçu des autres agriculteurs sur son propre comportement.

Non-linear change in body condition score over lifetime is associated with breed in dairy cows in Germany.

Optimal body condition is crucial for the well-being and optimal productivity of dairy cows. However, body condition depends on numerous, often interacting factors, with complex relationships between them. Moreover, most of the studies describe the body condition in Holstein cattle, while condition of some breeds, e.g. Simmental (SIM) and Brown Swiss (BS) cattle, have not been intensively studied yet. Body condition score (BCS) proved to be one of the most effective measures for monitoring body condition in dairy cows. Alterations in BCS were previously mainly studied over a single lactation period, while changes over the lifetime were largely ignored. This study was designed to report BCS of German SIM and BS cows in the light of the broadly accepted BCS in German Holstein (GH) cows and to explore patterns of change in BCS over the productive lifetime of animals. BCS was modeled via linear mixed effects regression, over- and undercondition of animals were studied using mixed effects logistic regressions and condition of animals was explored with the multinomial log-linear model via neural networks. All models included an interaction between breed and age. We found BCS of SIM and BS to be higher than BCS of GH. Our results show that BCS of BS cows did not change over the lifetime. In contrast, the BCS of GH and SIM was found to have a non-linear (quadratic) shape, where BCS increased up to the years of highest productivity and then decreased in aging cows. Patterns of change between SIM and GH, however, differed. GH do not only reach their highest BCS earlier in life compared to SIM, but also start to lose their body condition earlier. Our dataset revealed that 23% of the animals scored were over- and 14% underconditioned. The proportion of cows that were overconditioned was high (>10% of cows) for every breed and every age, while severe underconditioning (>10% of cows) occurred only in middle aged and old GH. Moreover, we found that the probability of underconditioning of animals over lifetime increases, while the overconditioning decreases from the middle to older ages. Our findings highlight the importance of understanding the non-linear nature of BCS, and uncover the potential opportunity for improving the performance and welfare of dairy cows by adjusting their nutrition, not only during lactation, but also highly specific to breed and age.

Benchmarking calf health: Assessment tools for dairy herd health consultancy based on reference values from 730 German dairies with respect to seasonal, farm type, and herd size effects.

Good calf health is crucial for a successfully operating farm business and animal welfare on dairy farms. To evaluate calf health on farms and to identify potential problem areas, benchmarking tools can be used by farmers, herd managers, veterinarians, and other advisory persons in the field. However, for calves, benchmarking tools are not yet widely established in practice. This study provides hands-on application for on-farm benchmarking of calf health. Reference values were generated from a large dataset of the "PraeRi" study, including 730 dairy farms with a total of 13,658 examined preweaned dairy calves. At herd level, omphalitis (O, median 15.9%) was the most common disorder, followed by diarrhea (D, 15.4%) and respiratory disease (RD, 2.9%). Abnormal weight bearing (AWB) was rarely detected (median, 0.0%). Calves with symptoms of more than one disorder at the same time (multimorbidity, M) were observed with a prevalence of 2.3%. The enrolled farms varied in herd size, farm operating systems, and management practices and thus represented a wide diversity in dairy farming, enabling a comparison with similar managed farms in Germany and beyond. To ensure comparability of the data in practice, the reference values were calculated for the whole data set, clustered according to farm size (1-40 dairy cows (n = 130), 41-60 dairy cows (n = 99), 61-120 dairy cows (n = 180), 121-240 dairy cows (n = 119) and farms with more than 240 dairy cows (n = 138), farm operating systems (conventional (n = 666), organic (n = 64)) and month of the year of the farm visit. There was a slight tendency for smaller farms to have a lower prevalence of disorders. A statistically significant herd-size effect was detected for RD (p = 0.008) and D (p < 0.001). For practical application of these reference values, tables, diagrams, and an Excel® (Microsoft®) based calf health calculator were developed as tools for on-farm benchmarking (https://doi.org/10.6084/m9.figshare.c.6172753). In addition, this study provides a detailed description of the colostrum, feeding and housing management of preweaned calves in German dairy farms of different herd sizes and farm type (e.g., conventional and organic).

A machine learning approach using partitioning around medoids clustering and random forest classification to model groups of farms in regard to production parameters and bulk tank milk antibody status of two major internal parasites in dairy cows.

Fasciola hepatica and Ostertagia ostertagi are internal parasites of cattle compromising physiology, productivity, and well-being. Parasites are complex in their effect on hosts, sometimes making it difficult to identify clear directions of associations between infection and production parameters. Therefore, unsupervised approaches not assuming a structure reduce the risk of introducing bias to the analysis. They may provide insights which cannot be obtained with conventional, supervised methodology. An unsupervised, exploratory cluster analysis approach using the k-mode algorithm and partitioning around medoids detected two distinct clusters in a cross-sectional data set of milk yield, milk fat content, milk protein content as well as F. hepatica or O. ostertagi bulk tank milk antibody status from 606 dairy farms in three structurally different dairying regions in Germany. Parasite-positive farms grouped together with their respective production parameters to form separate clusters. A random forests algorithm characterised clusters with regard to external variables. Across all study regions, co-infections with F. hepatica or O. ostertagi, respectively, farming type, and pasture access appeared to be the most important factors discriminating clusters (i.e. farms). Furthermore, farm level lameness prevalence, herd size, BCS, stage of lactation, and somatic cell count were relevant criteria distinguishing clusters. This study is among the first to apply a cluster analysis approach in this context and potentially the first to implement a k-medoids algorithm and partitioning around medoids in the veterinary field. The results demonstrated that biologically relevant patterns of parasite status and milk parameters exist between farms positive for F. hepatica or O. ostertagi, respectively, and negative farms. Moreover, the machine learning approach confirmed results of previous work and shed further light on the complex setting of associations a between parasitic diseases, milk yield and milk constituents, and management practices.

Effectiveness of Anthelmintic Treatments in Small Ruminants in Germany.

Widespread anthelmintic resistance is a concern for small ruminant health and production worldwide. The current situation regarding anthelmintic efficacy is, however, not very well studied in Germany. Thus, a nationwide field study was undertaken to assess the effectiveness of 253 treatments performed in 223 small ruminant flocks by faecal egg count reduction test (FECRT) using pooled samples and a modified McMaster method. The percentage of Haemonchus contortus and non-Haemonchus eggs was determined by fluorescence microscopy following peanut agglutinin-fluorescein isothiocyanate staining. Treatments were chosen and performed by farmers together with their local veterinarian, and potentially confounding factors for FECRT results were addressed as far as possible by rigorous inclusion criteria. Reduced effectiveness was observed for treatments with all examined anthelmintic classes, but treatments with benzimidazoles and moxidectin showed significantly poorer results than monepantel, a closantel and mebendazole combination, and levamisole. Low case numbers precluded reliable assessment of avermectins. Unsuccessful treatments were frequently associated with the survival of H. contortus, but this was also observed for non-Haemonchus genera. The results are highly concerning, and sustainable approaches to parasite control are urgently needed to prevent further deterioration of this situation.

Rumen and Liver Fluke Infections in Sheep and Goats in Northern and Southern Germany.

Paramphistomidosis has recently been identified as an emerging parasitosis in Europe. This study estimated the prevalence of rumen flukes, Fasciola hepatica and Dicrocoelium dendriticum, in small ruminants in Germany and identified occurring rumen fluke species and potential predictors for fluke infections. Pooled fecal samples from 223 sheep farms and 143 goat farms in northern and southern Germany were examined by the sedimentation technique, and molecular species identification was performed on rumen-fluke-positive samples. In sheep, a flock prevalence of 2.2% was detected for rumen flukes. Calicophoron daubneyi was identified on four of five positive farms, while species identification failed in one flock. No rumen fluke eggs were detected in the examined goat herds. F. hepatica eggs were detected in 2.7% of the sheep flocks, while the herd prevalence was 5.6% in goats. Higher prevalence values of 21.1% (sheep) and 7.0% (goats) were observed for D. dendriticum. Mixed grazing with other ruminants and previously identified infections with rumen flukes and/or F. hepatica were identified as predictors for paramphistomidosis. The distribution of the three trematode species followed a geographical pattern associated with conditions favoring the relevant intermediate hosts. C. daubneyi is an established parasite in German sheep at a currently low prevalence.

A machine learning approach for modelling the occurrence of Galba truncatula as the major intermediate host for Fasciola hepatica in Switzerland.

Fasciolosis caused by the trematode Fasciola hepatica is an important parasitosis in both livestock and humans across the globe. Chronic infections in cattle are associated with considerable economic losses. As a prerequisite for an effective control and prevention of fasciolosis in cattle fine-scale predictive models on farm-level are needed. Since disease transmission will only occur where the mollusc intermediate host is present, the objective of our research was to develop a regression model that allows to predict the local presence or absence of Galba truncatula as principal intermediate host for Fasciola hepatica in Switzerland. By implementing generalized linear mixed models (GLMMs) a total amount of 70 variables were analysed for their potential influence on the likelihood πi of finding Galba truncatula at a certain site. Important site-specific features could be considered by selecting suitable modelling procedures. The statistical software R was used to conduct regression analysis, performing the grplasso and the glmmLasso method. The selection of parameters was based on 10-fold cross validation and the Bayesian Information Criterion (BIC). This yielded a total number of 19 potential predictor variables for the grplasso and 13 variables for the glmmLasso model, which also included random effects. Nine variables appeared to be relevant predictors for the occurrence of Galba truncatula in both models. These included reed/humid area, spring water, water bodies within a 100 m radius, and trees/bushes as powerful positive predictors. High soil depth, temperatures frequently exceeding 30 °C in the year preceding the search for snails and temperatures below 0 °C especially in the second year before were identified to exert an adverse effect on the occurrence of Galba truncatula. Temperatures measured near ground level proved to be more powerful predictors than macroclimatic parameters. Precipitation values seemed to be of minor impact in the given setting. Both regression models may be convenient for a fine-scale prediction of the occurrence of Galba truncatula, and thus provide useful approaches for the development of future spatial transmission models, mapping the risk of fasciolosis in Switzerland on farm-level.

Macrophages in dermal disease progression of phospholipase D4-deficient Fleckvieh calves.

A new gene defect in Fleckvieh calves leads to a syndrome with partial phenotype overlap with bovine hereditary zinc deficiency. A mutation in a gene encoding phospholipase D4 (PLD4), an endosomal exonuclease, causes the disorder. In mice, PLD4 activity indirectly regulates the Toll-like receptor 9 (TLR9) pathway via degradation of microbial DNA. PLD4 absence thus results in visceral macrophage activation comparable to human macrophage activation syndrome. In this study, disease progression and the role of macrophages in affected calves were monitored clinically, clinicopathologically, and histologically over time. Breeding data identified 73 risk matings of heterozygous carriers resulting in 54 potentially PLD4-deficient calves born on farms. PLD4 status was examined via 5'-exonuclease assay, detecting 6 calves carrying the defect. These were purchased and monitored daily until final necropsy. The calves developed progressive skin lesions starting with small scaling areas terminating in severe crusting dermatitis, especially in areas with mechanical exposure. Histological and immunohistochemical analyses indicated that macrophages with cytoplasmic vacuolation increased considerably in skin sections obtained weekly during the disease course. Macrophage increase correlated with increased dermal lesion severity. Macrophage activation was confirmed by prominent phagocytic activity in the superficial dermis using electron microscopy. Dermal mRNA abundance of CCL2 and CCL3 measured by quantitative polymerase chain reaction verified macrophage activation. Further increase in mRNA of downstream molecule MyD88 and cytokine IL12b connected bovine PLD4 deficiency to increased TLR9 pathway activation. In contrast to human macrophage activation syndrome, the main feature of bovine PLD4 deficiency was local disease in organs with contact to microbial DNA (skin, intestine, lungs).

What can we learn from past and recent Bavarian knowledge for the future development of European veterinary herbal medicine? An ethnoveterinary study.

ETHNOPHARMACOLOGICAL RELEVANCE: While the interest in finding medical solutions for the worldwide antibiotics crisis is rising, the legal possibility of simplified authorization of herbal veterinary medicinal products is dwindling. An important basis for both the preservation and development of knowledge in veterinary herbal medicine are pharmacological and clinical studies on the performance of herbal remedies, based on historical written sources on the treatment of farm animals with medicinal plants, as well as current ethnoveterinary research. Nevertheless, there is only limited systematic ethnoveterinary research in Europe, with the exceptions of the Mediterranean region, Switzerland and Austria. We conducted a survey on the ethnoveterinary knowledge of farmers in Bavaria, and analyzed two regional historical textbooks. AIM OF THE STUDY: We documented the local veterinary knowledge about livestock in Bavaria based upon local historical textbooks and upon ethnoveterinary interviews to discover opportunities for the future development of European veterinary herbal medicine. MATERIAL AND METHODS: In 2018/2019 we conducted 77 semi-structured interviews with 101 farmers from different types of farms. Detailed information about homemade herbal remedies (plant species, plant part, manufacturing process, source of knowledge) and the corresponding use reports (target animal species, category of use, route of administration, dosage, source of knowledge, frequency of use, last time of use and farmers' satisfaction) were collected. To compare our data with the literature, the use reports of two local historical textbooks were analyzed and compared with the data from the interviews. RESULTS: 716 homemade remedy reports (HRs) for altogether 884 use reports (URs) were documented in this study. We picked the 363 HRs that consisted of a single plant species with or without other natural products (HSHRs) for a deeper analysis. These HSHRs were prepared from 108 plant species that belonged to 57 botanical families. The most URs were documented for the families of: Asteraceae, Linaceae and Urticaceae. Calendula officinalis L. (Asteraceae), Linum usitatissimum L. (Linaceae) and Urtica dioica L. (Urticaceae) were the most often documented single species. A total of 448 URs were gathered for the 363 HSHRs. The largest number of URs was for treatments of gastrointestinal disorders and metabolic dysfunctions, followed by skin alterations and sores. For nearly half of the URs the source of knowledge was family and friends. For 80 URs the source of knowledge was different from that of the corresponding HSHRs. For 68% of the URs farmers mentioned at least one use during the last 5 years. Half of the plant species that were mentioned in the historical literature were also mentioned in URs by the interviewees. CONCLUSION: In Bavaria, medicinal plants are actively used by farmers to treat their livestock with a high level of satisfaction. The knowledge is not passed on from generation to generation in a purely static way, but is dynamically developed by the users in almost one fifth of the URs. Ethnoveterinary research combined with data from regional historical textbooks may facilitate pharmacological and clinical studies in veterinary medicine, and the discussion about a simplified registration for traditional herbal veterinary medicinal products.

Rumen (Calicophoron/Paramphistomum spp.) and Liver Flukes (Fasciola hepatica) in Cattle-Prevalence, Distribution, and Impact of Management Factors in Germany.

This study was carried out to determine the prevalence of rumen flukes on German cattle farms via the sedimentation technique, and to identify the rumen fluke species occurring in Germany. Additionally, the prevalence of patent Fasciola hepatica infections was determined. Furthermore, a short questionnaire was answered by the farmers. A prevalence of 5.5% and 9.5% was detected for rumen flukes and liver flukes, respectively. Coinfections occurred on 2.1% of farms. In northern Germany, the rumen fluke prevalence was higher than in southern Germany, while for liver fluke the distribution was reversed. Rumen flukes were mostly identified as Calicophoron daubneyi, but in four cases, sequencing revealed Paramphistomum leydeni for the first time in Germany. Grazing and feeding of fresh grass, as well as organic farming, were significantly associated with rumen and liver fluke occurrence. In contrast, suckler cow husbandry only had an influence on the occurrence of rumen flukes, but not liver flukes. Trematode eggs could be detected in both, farms with and without deworming. Since there were only a few studies about Paramphistomidosis in Germany, more attention should be paid to these parasitic diseases for animal welfare and animal health reasons.

Seroprevalence of Major Pasture-Borne Parasitoses (Gastrointestinal Nematodes, Liver Flukes and Lungworms) in German Dairy Cattle Herds, Association with Management Factors and Impact on Production Parameters.

Pasture-borne parasites adversely affect bovine health and productivity worldwide. In Europe, gastrointestinal nematodes, especially Ostertagia ostertagi, the liver fluke Fasciola hepatica and the lungworm Dictyocaulus viviparus represent the most important parasites of dairy cattle. The present study assessed exposure towards these parasites among 646 cattle herds in three parts of Germany during 2017-2019 via antibody detection in bulk tank milk (BTM). Overall, O. ostertagi levels indicative of production losses were detected in 41.2% (266/646; 95% confidence interval (CI): 37.4-45.1%) of BTM samples, while F. hepatica seroprevalence amounted to 14.9% (96/646; 95% CI: 12.2-17.9%). Only 2.3% (15/646; 95% CI: 1.4-3.9%) of samples were D. viviparus antibody-positive. Significantly lower O. ostertagi as well as F. hepatica seroprevalence was detected in dual-purpose breeds compared to high-performance breeds from the same region. Management factors related to parasite exposure included access to fresh grass and hay, silage quality and anthelmintic treatment. Furthermore, F. hepatica and O. ostertagi seropositivity was significantly associated with suboptimal herd-level body condition. Interestingly, the relationship between seropositivity and productivity differed between breed types. Negative impacts on milk yield were detected only in high-performance breeds, while O. ostertagi seropositivity was associated with a lower milk fat content in dual-purpose herds.