Combining early hyperthermia detection with metaphylaxis for reducing antibiotics usage in newly received beef bulls at fattening operations: a simulation-based approach

International audienceBovine Respiratory Disease (BRD) dramatically affects fattened young beef bull pens. How metaphylaxis and early detection help balance disease duration and antibiotics usage remains unclear. Our goal was to determine efficient control strategies, assessed on disease duration, antibiotics doses, and true positives, for various infection forces accounting for BRD pathogen diversity. A stochastic mechanistic individual-based model combined infectious processes, detection methods, and treatment protocols in a realistic simulated small-size pen. To enable veterinary experts to assess and revise model assumptions, a new artificial intelligence framework, EMULSION, was used to describe model features in an explicit and intelligible form. Parameters were calibrated from observed data. Overpassing on-farm reference scenario using boluses required to very early detect the first case while using longer hyperthermia for subsequent detections. Metaphylaxis was efficient only for high pathogen transmission. Besides concrete recommendations to farmers, EMULSION models could easily address other farming systems, treatments, and diseases

Combining early hyperthermia detection with metaphylaxis for reducing antibiotics usage in newly received beef bulls at fattening operations: a simulation-based approach

International audienceBovine Respiratory Disease (BRD) dramatically affects fattened young beef bull pens. How metaphylaxis and early detection help balance disease duration and antibiotics usage remains unclear. Our goal was to determine efficient control strategies, assessed on disease duration, antibiotics doses, and true positives, for various infection forces accounting for BRD pathogen diversity. A stochastic mechanistic individual-based model combined infectious processes, detection methods, and treatment protocols in a realistic simulated small-size pen. To enable veterinary experts to assess and revise model assumptions, a new artificial intelligence framework, EMULSION, was used to describe model features in an explicit and intelligible form. Parameters were calibrated from observed data. Overpassing on-farm reference scenario using boluses required to very early detect the first case while using longer hyperthermia for subsequent detections. Metaphylaxis was efficient only for high pathogen transmission. Besides concrete recommendations to farmers, EMULSION models could easily address other farming systems, treatments, and diseases

BVD : le point sur la vaccination

National audienceLes vaccins les plus récents présentent en termes d’innocuité et d’efficacité des caractéristiques telles qu’ils deviennent des outils performants dans la lutte à mener contre la BVD. A l’heure actuelle, trois armes existent donc dans cette lutte, l’identification et l’élimination des IPI, les mesures de biosécurité et la vaccination. Elles se complètent les unes avec les autres. Plutôt que de les opposer, il faut savoir utiliser au mieux chacune d’entre elles, au vu des circonstances épidémiologiques locales (séroprévalence initiale, densité des élevages bovins)

IVAN (Innovative Veterinary Assisted Necropsy): A Diagnosis Support System for Veterinary Necropsy Based on Bayesian Network

International audienc

A Diagnosis Support System for Veterinary Necropsy based on Bayesian Networks

International audienceVeterinary autopsy requires a high level of expertise and skills that not all veterinarians necessarily master, especially in the context of the desertification of rural areas. The development of support systems is a challenging issue, since such a tool, to be considered relevant and accepted by practitioners in their diagnosis process, must avoid any black box effect. The diagnosis support system we introduce here, IVAN (“Innovative Veterinary Assisted Necropsy”), aims to engage the user in an explicit, understandable, validable and reviewable process, able to cope with the specific issues of cattle necropsy. Besides, it provides uncertainty management to deal with approximate lesion descriptions. IVAN relies on a Bayesian network to infer relevant proposals at each step of the diagnostic process. IVAN was trained on a set of real autopsy cases from autopsy reports, and its performance was assessed using another set of reports. In addition, the tool had to provide results in short r esponse time and be able to run the application on mobile device and web server. In addition to demonstrating the feasibility of the approach, IVAN is a first step towards other support systems in other species and in broader contexts than autopsy

Infectious Bovine Respiratory Diseases in Adult Cattle: An Extensive Necropsic and Etiological Study

In young cattle, bovine respiratory disease (BRD) is a major cause of death and Mannheimia haemolytica is a frequent pathogen. Knowledge of fatal BRD in adult cattle is more limited. We assessed the importance of infectious BRD as a cause of death in adult cattle and determined the associated pathogens. We analyzed data from 737 adult cattle necropsies at the Pathology Unit for Large Animals at Oniris, Nantes, France over a 6 year period (2013–2019). Each carcass was subjected to a complete necropsy. Lungs showing macroscopic lesions were classified into three categories: infectious primary pulmonary (IPP) lesions, thromboembolic pneumonia (TEP) and others (aspiration pneumonia, verminous pneumonia, and local extension of an extra-pulmonary inflammatory process). Half of the lungs with IPP macroscopic lesions were sampled for histology and submitted for polymerase chain reaction. BRD was the second leading cause of death (15.7%) after digestive diseases (32.2%). A strong predominance of IPP lesions (42.3%) and TEP lesions (39.6%) was also demonstrated. In IPP macroscopic lesions, fibrinous, hemorrhagic and/or hecrotic (FHN) bronchopneumonia accounted for 77.6% of macroscopic lesions. Mannheimia haemolytica was significantly associated with FHN bronchopneumonia macroscopic lesions. This study suggests that Mannheimia haemolytica should be included in the differential diagnosis of BRD in adult cattle

Ultrasonography of the cranial part of the thorax is a quick and sensitive technique to detect lung consolidation in veal calves

Abstract Background In the veal calf industry, bovine respiratory disease is the main cause of morbidity and mortality. Lung ultrasonography (LUS) is an accurate technique to diagnose bronchopneumonia in calves. Due to the economic constraints faced by the industry, a screening technique able to rapidly examine large numbers of calves is required. Objective To determine if lung ultrasonography focusing on the cranial part of the thorax (1st to 2nd intercostal space (ICS) on the right and 2nd to 3rd on the left) and/or on the middle part of the thorax (3rd to 5th ICS on the right and 4th to 5th on the left) (alternative techniques) are rapid screening techniques as sensitive as LUS of the entire lung (reference technique) to identify calves with lung consolidation lesions. Methods Data on 300 veal calves aged 33.1 ± 8.0 days and weighing on average 67.5 ± 4.0 kg at LUS from two farms were analysed. Systematic LUS of the entire lung was performed on all calves and a lung consolidation score was given to different parts of the thorax. Agreements between the alternative and the reference techniques were measured by Cohen's κ, McNemar's test and weighted κ. Results Agreement between LUS focusing on the cranial + middle part or on the cranial part only of the thorax and the reference technique were almost perfect with a cutoff of 1 cm. The relative sensitivity of these two alternative techniques was high (> 93%). Conclusion Lung ultrasonography of the cranial + middle part or on the cranial part only of the thorax are quick and sensitive techniques to identify veal calves with lung consolidation lesions shortly after arrival at the facility

Early detection of bovine respiratory disease in young bulls using reticulo-rumen temperature boluses

PosterInternational audienc

Improved detection of bovine respiratory disease in young bulls using rumen temperature boluses

International audienc

Mobilité réseau robuste pour service de téléexpertise vétérinaire par lunettes connectées

Dans le cadre de ses activités de consultations, ONIRIS offre, via des lunettes connectées, une téléexpertise auprès des vétérinaires ruraux. Ce service donne au vétérinaire, lors de ses consultations, accès en temps réel voix et vidéo à un expert situé dans son lieu de travail devant son ordinateur afin de guider le vétérinaire dans son intervention. Le lieu d’exercice de ces praticiens se situe majoritairement dans les exploitations agricoles en milieu rural généralement caractérisé par une couverture réseau très aléatoire. De plus, dans les exploitations agricoles, les bâtiments d’élevage en tôle métallique font souvent obstacle à la propagation radio. Un tel contexte géographique et architectural peut devenir rédhibitoire pour le déploiement, l’usage effectif et l’adoption par les vétérinaires, de services comme la téléexpertise. Dans ce travail, une solution simple d’utilisation nécessitant un minimum de manipulations par les vétérinaires, est proposée pour permettre à ces derniers, de pouvoir communiquer sans interruption et avec une qualité de son et d’image nettement améliorée lors de leurs interventions en milieu rural. Dans un premier temps, une étude en laboratoire est menée pour étudier les différentes situations de pertes de connectivité. Différentes solutions techniques sont développées en prenant en compte les différents cas de figure que peuvent rencontrer lesvétérinaires lors de leurs interventions en milieu rural. Ces solutions sont évaluées par des séries de tests en situation opérationnelle, obéissant au format de l’épidémiologie descriptive dans des exploitations en Loire Atlantique et dans le Maine et Loire, sélectionnées pour leurs connectivités réseaux défaillantes. Les expérimentations montrent que dans toutes les exploitations visitées, quel que soit le niveau de couverture de la zone, quel que soit le type de bâtiment où se fait le test, les solutions proposées compensent la mauvaise connectivité et permettent au praticien de réaliser correctement ses opérations