Héritabilité des maux de pattes et relations avec les performances de reproduction de la lignée INRA 1777

Les maux de pattes ont été identifiés comme la première cause de réforme sanitaire des femelles dans les élevages. Le but de cette étude est d’évaluer les différences de performances zootechniques des animaux présentant des maux de pattes et de déterminer l’héritabilité de ce caractère. Les enregistrements des performances de 2933 reproducteurs (2200 femelles et 733 mâles) nés entre 2004 et 2015 de la lignée INRA 1777 ont été analysés. La présence de maux de pattes est enregistrée à chaque cycle, pendant la pesée dite « de palpation », 14 jours après l’IA. Les femelles représentent 96,5% des animaux atteints. La proportion de lapines souffrant de pododermatite varie de 0,10 % à la palpation 1 à 15,7% à la palpation 5. Les femelles présentant des maux de pattes ont un taux de mise bas significativement plus faible, un poids vif et une croissance inférieure. Les différences entre femelles atteintes et non-atteintes ne sont pas significatives pour le nombre de nés vivants, la mortinatalité et la mortalité en pré-sevrage. L’héritabilité de la présence de maux de pattes (présence de maux de pattes au moins une fois au cours des 6 premières palpations) est de 0,07± 0,03 avec un modèle linéaire et de 0,13 ± 0,05 avec un modèle à seuil. Ce caractère pourrait donc éventuellement être inclus dans les objectifs de sélection.Sore hocks are the first cause of female sanitary culling in the commercial rabbit farms. The aims of his study were to analyses the performance gap of affected rabbits and estimate the heritability of pododermatitis. Records on 2933 rabbits (2200 females and 733 males) born between 2004 and 2015 of the INRA 1777 rabbit line were analyzed. Pododermatitis was registered at each reproduction cycle during the “palpation” weighing which occurs 14 days after Artificial Insemination. Females represent 96.5% of the affected rabbits. The proportion of does showing sore hocks reached 0.10% at the first palpation and 15.7% at the fifth palpation. In total, 15.6% of the females showed sore hocks at least once during the first 6 palpations. Females suffering from sore hocks have a lower fertility, a lower body weight at palpation and a lower average daily gain between palpations. They were no significant differences for the number of born alive, mortinatality and pre-weaning death rate. The heritability of pododermatitis (presence of pododermatitis at least once during the first 6 palpations) was 0.07± 0.03 with a linear model and 0.13 ± 0.05 with a threshold model. This trait might therefore be included in the breeding objectives

Mycobacterium Species Related to M. leprae and M. lepromatosis from Cows with Bovine Nodular Thelitis

Bovine nodular thelitis is a granulomatous dermatitis associated with infection with acid-fast bacteria. To identify the mycobacterium responsible for this infection, we conducted phylogenetic investigations based on partial sequencing of 6 genes. These bacteria were identified as an undescribed Mycobacterium species that was phylogenetically related to M. leprae and M. lepromatosis

Seasonal dynamics and stoichiometry of the planktonic community in the NW Mediterranean Sea : a 3D modeling approach

International audienceThe 3D hydrodynamic Model for Applications at Regional Scale (MARS3D) was coupled with a biogeochemical model developed with the Ecological Modular Mechanistic Modelling (Eco3M) numerical tool. The three-dimensional coupled model was applied to the NW Mediterranean Sea to study the dynamics of the key biogeochemical processes in the area in relation with hydrodynamic constraints. In particular, we focused on the temporal and spatial variability of intracellular contents of living and non-living compartments. The conceptual scheme of the biogeochemical model accounts for the complex food web of the NW Mediterranean Sea (34 state variables), using flexible plankton stoichiometry. We used mechanistic formulations to describe most of the biogeochemical processes involved in the dynamics of marine pelagic ecosystems. Simulations covered the period from September 1, 2009 to January 31, 2011 (17 months), which enabled comparison of model outputs with situ measurements made during two oceanographic cruises in the region (Costeau-4: April 27-May 2, 2010 and Costeau-6: January 23-January 27, 2011)

Desynchronization Strain Patterns and Contractility in Left Bundle Branch Block through Computer Model Simulation

International audienceLeft bundle branch block (LBBB) is associated with specific septal-to-lateral wall activation patterns which are strongly influenced by the intrinsic left ventricular (LV) contractility and myocardial scar localization. The objective of this study was to propose a computational-model-based interpretation of the different patterns of LV contraction observed in the case of LBBB and preserved contractility or myocardial scarring. Two-dimensional transthoracic echocardiography was used to obtain LV volumes and deformation patterns in three patients with LBBB: (1) a patient with non-ischemic dilated cardiomyopathy, (2) a patient with antero-septal myocardial scar, and (3) a patient with lateral myocardial scar. Scar was confirmed by the distribution of late gadolinium enhancement with cardiac magnetic resonance imaging (cMRI). Model parameters were evaluated manually to reproduce patient-derived data such as strain curves obtained from echocardiographic apical views. The model was able to reproduce the specific strain patterns observed in patients. A typical septal flash with pre-ejection shortening, rebound stretch, and delayed lateral wall activation was observed in the case of non-ischemic cardiomyopathy. In the case of lateral scar, the contractility of the lateral wall was significantly impaired and septal flash was absent. In the case of septal scar, septal flash and rebound stretch were also present as previously described in the literature. Interestingly, the model was also able to simulate the specific contractile properties of the myocardium, providing an excellent localization of LV scar in ischemic patients. The model was able to simulate the electromechanical delay and specific contractility patterns observed in patients with LBBB of ischemic and non-ischemic etiology. With further improvement and validation, this technique might be a useful tool for the diagnosis and treatment planning of heart failure patients needing CRT

Relationship between resistance to a Pasteurella Multocida experimental infection and production traits in rabbits

International audienceNine hundred and fifty five rabbits were inoculated at 6 weeks of age with a pyogenic strain of Pasteurella multocida and were scored for resistance from 0 to 4 by taking into account postmortem examinations. Fifty five sires having at least 10 inoculated offspring produced also 9943 rabbits tested for health and growth and 1468 females tested for reproduction in commercial farm conditions. Total number born and number born alive per litter were significantly lower in daughters of resistant sires (-0.27 and-0.41). Prevalence of digestive diseases and infectious diseases were significantly lower in the resistant growing rabbits than in the susceptible ones (-1.7 point and-3.0 points, respectively). This result suggests that resistance to pasteurellosis assessed by an experimental infection is favorably correlated to resistance to other infectious diseases

Relations entre la résistance à la pasteurellose après infection expérimentale et les caractères de croissance et de reproduction mesurés en élevage commercial

National audienceLa pasteurellose une maladie bactérienne parmi les plus répandues en élevage cunicole. Le projet RELAPA a pour objectif d’étudier le déterminisme de la résistance à la pasteurellose. Un total de 955 lapins de 6 semaines, issus de 28 mâles appartenant à 6 lignées commerciales, ont été inoculés avec une pasteurelle pyogène et 2 semaines plus tard une note de résistance de 0 à 4 leur a été attribuée après sacrifice. Ces notes ont servi à classer les 28 mâles en 2 groupes,14 résistants et 14 sensibles, d'après la note moyenne de résistance de leur descendance. Par ailleurs ces 28 mâles, dans des élevages commerciaux, ont engendré 5164 lapereaux contrôlés pour leur croissance et 884 femelles reproductrices qui ont elles-mêmes fourni 3568 portées contrôlées. Le seul caractère qui présentait une différence significative entre les descendants de 14 mâles résistants et de14 mâles sensibles était la fertilité, avec une différence de 7 points en faveur du groupe des mâles résistants. Les corrélations résiduelles entre la note de résistance et les caractères de production étaient toutes faibles et non significativement différentes de zéro. Les corrélations génétiques entre la résistance et les caractères pondéraux étaient positives mais non significativement différentes de zéro (0,32 ± 0,51 pour le poids au sevrage et 0,27 ±0,49 pour le poids final). Les corrélations génétiques entre la note de résistance moyenne et les caractères de reproduction étaient défavorables mais non significativement différentes de zéro (-0,43 ± 0,45, -0,68 ± 0,40, 0,70 ± 0,65 respectivement pour le nombre de nés totaux par portée, le nombre de nés vivants par portée et la mortinatalité). Ces valeurs de corrélations génétiques sont données pour information mais elles doivent être interprétées avec beaucoup de prudence car leur précision est très faible

Génétique de la résistance à la pasteurellose chez le lapin

International audienc

Pasteurella multocida experimental infection 1): resistance and hematological response

International audiencePasteurellosis is the first cause of female mortality in rabbit farms. During the RELAPA project (Genomics for the Genetic Resistance of Rabbits to Pasteurellosis), 953 rabbits were inoculated at 6 weeks of age with a pyogenic strain of Pasteurella multocida (Pm) and were monitored during 14 days. Disease response was very variable among animals, with 7% of resistant animals and 11% of highly susceptible rabbits. Blood cell counts were performed at day 14 after inoculation on 574 inoculated and 28 control rabbits. Significant differences in white blood cell, red blood cell, and platelet counts were observed according to the disease resistance score. Susceptible rabbits have a lower red blood cell count, probably due to the hemolytic and hemorrhagic activity of Pm. They also have a higher percentage of monocytes, neutrophils and eosinophils (mainly involved in the innate immune system and inflammatory responses) and, conversely, a lower percentage of lymphocytes (mainly involved in the adaptive immune response) compared to highly resistant and control rabbits. They do not seem able to mount an effective immune response to control the infection

Pasteurella multocida experimental infection (2): genetic parameters

International audienceIn this study, we experimentally infected 953 crossbred rabbits from 6 sire lines with Pasteurella multocida, and diagnosed their response to Pasteurellosis. We recorded abscess and bacterial dissemination, growth before and after inoculation, and performed blood cell counts 14 days post inoculation. The heritabilities were low to moderate for all traits, except for the eosinophils percentage, which does not seem to be heritable. There were positive genetic correlations between the Resistance score and the red blood cell count, the hematocrit, hemoglobin and lymphocyte percentages. On the opposite, there were negative genetic correlations between the Resistance score and the platelets, the white blood cells, the neutrophil and monocytes percentages. Among the hematological traits, lymphocyte percentage could be a potential selection criterion to breed for Pasteurellosis resistance. Its heritability was relatively high (0.24 ± 0.09) compared to the other traits and its correlation with the Resistance score was also high (0.83). This is the first analyses of the genetic parameters of hematological traits in experimentally infected rabbits