Questionnaire-based assessment of wild boar/domestic pig interactions and implications for disease risk management in Corsica

Wild boars and domestic pigs belong to the same species (Sus scrofa). When sympatric populations of wild boars, feral pigs, and domestic pigs share the same environment, interactions between domestic and wild suids (IDWS) are suspected to facilitate the spread and maintenance of several pig pathogens which can impact on public health and pig production. However, information on the nature and factors facilitating those IDWS are rarely described in the literature. In order to understand the occurrence, nature, and the factors facilitating IDWS, a total of 85 semi-structured interviews were implemented face to face among 25 strict farmers, 20 strict hunters, and 40 hunting farmers in the main traditional pig-farming regions of Corsica, where IDWS are suspected to be common and widespread. Different forms of IDWS were described: those linked with sexual attraction of wild boars by domestic sows (including sexual interactions and fights between wild and domestic boars) were most frequently reported (by 61 and 44% of the respondents, respectively) in the autumn months and early winter. Foraging around common food or water was equally frequent (reported by 60% of the respondents) but spread all along the year except in winter. Spatially, IDWS were more frequent in higher altitude pastures were pig herds remain unattended during summer and autumn months with limited human presence. Abandonment of carcasses and carcass offal in the forest were equally frequent and efficient form of IDWS reported by 70% of the respondents. Certain traditional practices already implemented by hunters and farmers had the potential to mitigate IDWS in the local context. This study provided quantitative evidence of the nature of different IDWS in the context of extensive commercial outdoor pig farming in Corsica and identified their spatial and temporal trends. The identification of those trends is useful to target suitable times and locations to develop further ecological investigations of IDWS at a finer scale in order to better understand diseases transmission patterns between populations and promote adapted management strategies

Prediction of pig trade movements in different European production systems with exponential random graph models

In most European countries, data regarding movements of live animals are routinely collected and can greatly aid predictive epidemic modeling. However, the use of complete movements' dataset to conduct policy-relevant predictions has been so far limited by the massive amount of data that have to be processed (e.g., in intensive commercial systems) or the restricted availability of timely and updated records on animal movements (e.g., in areas where small-scale or extensive production is predominant). The aim of this study was to use exponential random graph models (ERGMs) to reproduce, understand, and predict pig trade networks in different European production systems. Three trade networks were built by aggregating movements of pig batches among premises (farms and trade operators) over 2011 in Bulgaria, Extremadura (Spain), and Côtes-d'Armor (France), where small-scale, extensive, and intensive pig production are predominant, respectively. Three ERGMs were fitted to each network with various demographic and geographic attributes of the nodes as well as six internal network configurations. Several statistical and graphical diagnostic methods were applied to assess the goodness of fit of the models. For all systems, both exogenous (attribute-based) and endogenous (network-based) processes appeared to govern the structure of pig trade network, and neither alone were capable of capturing all aspects of the network structure. Geographic mixing patterns strongly structured pig trade organization in the small-scale production system, whereas belonging to the same company or keeping pigs in the same housing system appeared to be key drivers of pig trade, in intensive and extensive production systems, respectively. Heterogeneous mixing between types of production also explained a part of network structure, whichever production system considered. Limited information is thus needed to capture most of the global structure of pig trade networks. Such findings will be useful to simplify trade networks analysis and better inform European policy makers on risk-based and more cost-effective prevention and control against swine diseases such as African swine fever, classical swine fever, or porcine reproductive and respiratory syndrome

Evaluation des mesures de maîtrise de la dermatite digitée dans les troupeaux bovins laitiers

The aim of this PhD thesis was to assess the effectiveness of different promising measures to durably decrease the prevalence of digital dermatitis (DD) in dairy herds. The treatment modalities to be studied should be acceptable for farmers and not toxic both for Human and the Environment. A first part was dedicated to investigate the motivations and limits of French dairy farmers towards the implementation of different treatments against DD. The need for evidence of optimal frequency of application of collective treatments with footbath or another way of application was enlighten. After the development and the assessment of a simple method for scoring of DD lesions in the milking parlor, a clinical trial was conducted in 52 dairy herds. This clinical trial aimed at assessing, using survival analysis, the relative effectiveness of 4 different treatment regimens and herd practices to decrease the incidence and increase the cure rate of DD lesion. The implementation of walk-through footbath and collective spraying using a solution of chelated minerals were effective to significantly decrease the incidence and improve cure rate of DD lesions when applied over 2 days every fortnight. Legs hygiene and hoof trimming before DD detection were also found crucial to control DD. Lastly, the impact of DD on milk yield was estimated to 0,6 to 0,9 kg/day. These results highlight the need of combining several control measures, including both treatments and herd practices to design relevant control strategies of DD in dairy herds.L’objectif de cette thèse était d’évaluer des mesures jugées prometteuses pour diminuer durablement la prévalence de la dermatite digitée (DD) dans les troupeaux bovins laitiers. Les pratiques de traitement devaient être efficaces, acceptables pour les éleveurs et non toxiques pour l’Homme et l’Environnement. Une première partie s’est intéressée aux freins et motivations des éleveurs français vis-à-vis des pratiques de traitement de la DD. Il en ressortait le besoin d’identifier des régimes optimaux d’application des traitements, tout en étudiant des alternatives au pédiluve pour l’application de traitements collectifs. Après avoir mis au point et évalué une méthode simple de notation de la DD en salle de traite, un essai clinique a été mené dans 52 troupeaux bovins laitiers. Cet essai a permis d’évaluer, à l’aide d’analyses de survie, l’efficacité relative de 4 protocoles de traitement et des pratiques d’élevage pour diminuer l’incidence et améliorer la guérison des lésions de DD. Il a été montré qu’un traitement à base de minéraux chélatés appliqué 2 jours toutes les 2 semaines, via un pédiluve de passage ou une application par spray ensalle de traite est efficace pour diminuer l’incidence et améliorer la guérison clinique des lésions de DD. La propreté des pieds et la réalisation d’un parage avant la détection d’une lésion de DD jouaient également un rôle essentiel. Enfin, l’impact de la DD sur la production laitière a pu être estimé à 0,6 à 0,9 kg/jour. Les résultats de cette thèse renforcent la nécessité d’une approche globale qui intègre des protocoles de traitement et les pratiques d’élevage pour élaborer des stratégies de contrôle de la DD efficaces et rentable

Médecine et élevage de précision : surveillance et détection précoce individualisée en élevage

L’élevage de précision s’appuie sur un grand nombre de données, souvent individualisées, générées par des outils de monitoring, avec pour objectif principal de préserver les performances techniques et économiques des élevages mais aussi souvent d’améliorer le bien-être des animaux, d’adapter l’alimentation et de réduire l’impact environnemental. Le développement d’une médecine vétérinaire de précision – ou personnalisée –, s’appuyant sur les outils de l’élevage de précision pourrait permettre le recours à des thérapeutiques personnalisées évitant les traitements collectifs diminuant ainsi l’usage d’antibiotiques. La masse de données générées pourrait aussi servir d’autres applications : surveillance syndromique ou phénotypage haut débit.Precision livestock farming leans on a large number of individualized data generated by monitoring systems. Objectives of precision livestock farming is mainly to maintain technical and economic performances but also to improve animal welfare, to adjust livestock feeding and to reduce environmental impact. The development of a veterinary precision medicine –or veterinary personalized medicine- based on tools used for precision livestock farming could allow personalized treatments and avoid mass medication. The mass of generated data could also serve other applications, for instance, syndromic surveillance and high resolution phenotyping

Subarachnoid anesthesia in sedated calves undergoing umbilical surgery: Comparison of procaine 2% and lidocaine 2% associated with xylazine 2%

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