77 research outputs found
Detection and epidemiological analysis of animal emerging diseases for control purpose: how to take up the challenge?
The presentation first presents the global framework for the study of emerging diseases aiming at
disease control, sanitary crises avoidance and promotion of sustainable agriculture. Then, the different
stages, methods and tools that are needed for emerging disease study are presented. These
can be either available, under development or awaiting for research studies. They mainly concern
information system, biomathematics, epidemiology and molecular biology. Finally, some of the
main organizational principles (synergy between health protagonists) are introduced. These principles
have to be realized if we want to reach an efficient vigilance towards potentially emerging
diseases and to take up the challenge that is facing animal populations and human societies en
route for globalization.La communication présente
d'abord le cadre global de l'Ă©tude des maladies Ă©mergentes Ă des fins de contrĂ´le,
d'Ă©vitement des crises sanitaires et de promotion de l'agriculture durable. Sont ensuite
présentés les différentes étapes, méthodes et outils existants, en cours de mise au point ou
nécessitant un travail de recherche (en matière de systèmes d'information, de
biomathématiques, d'épidémiologie et de biologie moléculaire), en vue d'être utilisés dans
l'étude des émergences. Au bout du compte, sont posés quelques principes d'organisation
(synergies entre les acteurs du sanitaire) qui seraient à concrétiser pour aboutir à une
vigilance efficace vis Ă vis des maladies potentiellement Ă©mergentes et pouvoir relever au
mieux le défi qu'elles posent aux sociétés animales et humaines en voie de
globalisation
Detecting Emerging Diseases in Farm Animals through Clinical Observations
Clinical observations will allow early detection of emerging diseases in animal to enhance response time and capabilities
L'enquête éco-pathologique continue : 2. Le bilan automatisé de pathologie clinique en élevage laitier : un système d'objectivation des problèmes sanitaires
National audienc
Les boiteries chez la vache laitière. Synthèse des résultats de l'enquête éco-pathologique continue
National audienceLa pathologie du pied chez la vache laitière représente un ensemble d’affections qui touche en moyenne près d’un animal sur cinq dans les élevages, et peut représenter un véritable fléau économique dans certaines exploitations très atteintes. Cette pathologie paraît fortement liée au système de production c’est-à -dire à la nature du bâtiment (19,3 % de boiteries en stabulation libre permanente vs 9,7 % en stabulation entravée), au degré d’intensification de l’élevage (plus grande sensibilité des vaches pie-noires, hautes productrices, aux affections podales), à l’alimentation (plus grand nombre de cas de boiteries métaboliques répertorié lorsque la ration de base comprend de l’ensilage de maïs à volonté et lorsque les changements de ration sont plus nombreux en période hivernale). L’augmentation des fréquences observées semble être le corollaire d’une production intensifiée. Cependant, il n’y a pas de lien de cause à effet. Plus simplement l’intensification nécessite une meilleure maîtrise technique de la part de l’éleveur. Les fautes de conduite en matière de prévention des boiteries (absence de méthodes prophylactiques telles que parage préventif, passage au pédiluve), l’absence de complémentation minérale, les excès alimentaires, une mauvaise conception du bâtiment sur le plan du confort et de la protection contre les intempéries, sont sanctionnées par une augmentation significative des troubles podaux observés
Facteurs de risque nutritionnels de la pathologie hépatique dans les troupeaux bovins laitiers en France
Nutritional risk factors for liver damage were surveyed in Black-Pied French dairy herds using serum glutamic dehydrogenase and gamma glutamyl transferase levels to monitor liver dysfunction. The 34 herds chosen were free of parasitic liver injuries. Feeding systems, nutritional blood parameters and production characteristics are analyzed. Two risk factors appeared to be involved in hepatic injury: feeding of fresh rape (Brassica napus) and high levels of serum urea (≥6.64 mmol/L) associated with grass pasture or dietary nonprotein nitrogen with corn silage
Facteurs environnementaux de variations de l'abondance des tiques Ixodes ricinus dans des zones d'étude modèles en Auvergne
De 2003 à 2006, dans la région des Combrailles et dans l'Ouest Cantal, les nymphes Ixodes ricinus ont été collectées "au drapeau" sur le périmètre intérieur de prairies permanentes pâturées par les bovins. Une approche probabiliste basée sur la loi binomiale négative a montré que l'abondance des nymphes I. ricinus était liée à la présence d'une haie d'arbres ou d'arbustes, à la présence de bois, et au nombre de nymphes dans le bois le plus proche des pâtures, étayant l'hypothèse qu'une migration des tiques des bois vers les pâtures est cruciale pour le maintien d'une population de tiques I. ricinus sur les pâtures. Grâce aux piégeages réalisés en 2005 le mulot sylvestre a été identifié comme l'espèce de micromammifères jouant le rôle de "pont épidémiologique" entre bois et pâtures. Les conditions du risque de morsure par I. ricinus en Auvergne ont été ainsi précisées, en tant qu'étape initiale d'évaluation du risque de transmission d'agents pathogènes via cette tiqueCLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF
Statistical modelling for clinical mastitis in the dairy cow: problems and solutions.
Modelling case occurrence and risk factors for clinical mastitis, as a key multifactorial disease in the dairy cow, requires statistical models. The type of model used depends on the choice of perception or the study level: herd, lactation, animal, udder and quarter. The validity of the tests that are performed through these models is especially ensured when hypotheses of independence between statistical units are respected, and when the model adjustments do not involve overdispersion faced with the observed data. In the article, the main sources of overdispersion are identified according to the different levels of perception of mastitis risk. Then, the proposed solutions to control for overdispersion at each study level are discussed and the difficulty to compare the study results is highlighted through a variety of methodological choices of the authors. Two main categories of models are used for modelling clinical mastitis, i.e. generalist exploratory models and explanatory designed models. The contribution of the explanatory models to improve modelling accuracy and relevance is documented through the two main published methodological approaches, the first one being based on a states model, and the second on a survival model. The integration and optimisation of such explanatory modelling methods should be possible in the future in order to develop a more global explanatory model including herd risk factors, which could pertinently predict udder infections (both clinical and subclinical) at the cow, lactation, or even udder and quarter levels.Modelling case occurrence and risk factors for clinical mastitis, as a key multifactorial disease in the dairy cow, requires statistical models. The type of model used depends on the choice of perception or the study level: herd, lactation, animal, udder and quarter. The validity of the tests that are performed through these models is especially ensured when hypotheses of independence between statistical units are respected, and when the model adjustments do not involve overdispersion faced with the observed data. In the article, the main sources of overdispersion are identified according to the different levels of perception of mastitis risk. Then, the proposed solutions to control for overdispersion at each study level are discussed and the difficulty to compare the study results is highlighted through a variety of methodological choices of the authors. Two main categories of models are used for modelling clinical mastitis, i.e. generalist exploratory models and explanatory designed models. The contribution of the explanatory models to improve modelling accuracy and relevance is documented through the two main published methodological approaches, the first one being based on a states model, and the second on a survival model. The integration and optimisation of such explanatory modelling methods should be possible in the future in order to develop a more global explanatory model including herd risk factors, which could pertinently predict udder infections (both clinical and subclinical) at the cow, lactation, or even udder and quarter levels
A spatial hazard model for cluster detection on continuous indicators of disease: application to somatic cell score
Methods for spatial cluster detection dealing with diseases quantified by continuous variables are few, whereas several diseases are better approached by continuous indicators. For example, subclinical mastitis of the dairy cow is evaluated using a continuous marker of udder inflammation, the somatic cell score (SCS). Consequently, this study proposed to analyze spatialized risk and cluster components of herd SCS through a new method based on a spatial hazard model. The dataset included annual SCS for 34 142 French dairy herds for the year 2000, and important SCS risk factors: mean parity, percentage of winter and spring calvings, and herd size. The model allowed the simultaneous estimation of the effects of known risk factors and of potential spatial clusters on SCS, and the mapping of the estimated clusters and their range. Mean parity and winter and spring calvings were significantly associated with subclinical mastitis risk. The model with the presence of 3 clusters was highly significant, and the 3 clusters were attractive, i.e. closeness to cluster center increased the occurrence of high SCS. The three localizations were the following: close to the city of Troyes in the northeast of France; around the city of Limoges in the center-west;and in the southwest close to the city of Tarbes. The semi-parametric
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