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The present study aims to assess (1) the ecosystem services (ES) provided by LFS and (2) the differential ES between local (Creole) and exotic breeds from pig, cattle and goat. The ES are defined as the benefits that humans derive from LFS. They were summarized in 12 ES indicators that cover services related to provisioning, ecological and socio-cultural aspects and territorial vitality. A total of 106 LFS units that covers the five agroecological zones of Guadeloupe were analysed. Functional typologies of LFS per species were created from surveys. The effect of breed on the ES indicators was tested. Results showed that the 40 pig LFS units were separated into 3 clusters that were differentiated in ES according to provisioning ES (cluster 1), cultural use and sale to the neighborhood (cluster 2) and pork self-consumption (cluster 3). The typology of the 57 farms with cattle distinguished 4 clusters with differences in ES provided in self-consumption (cluster1), ecological ES (cluster 2), socio-cultural ES for racing or draught oxen (cluster 3) and ES associated with territory vitality (cluster 4). The 66 goat LFS units were classified into 3 clusters different in ES concerning self-consumption (cluster 1), cultural aspects (cluster 2) and provisioning ES (cluster 3). Our study highlights that ES indicators are not breed dependent (P > 0.10) but rather livestock farming system dependent. The ES rely more on the rearing management than on the breed type, and up to now, there are no specifications in Guadeloupe to differentiate management between breeds.

The use of chlordecone (CLD), a chlorinated polycyclic pesticide used in the French West Indies banana fields between 1972 and 1993, resulted in a long-term pollution of agricultural areas. It has been observed that this persistent organic pollutant (POP) can transfer from contaminated soils to food chain. Indeed, CLD is considered almost fully absorbed after involuntary ingestion of contaminated soil by outdoor reared animals. The aim of this study was to model toxicokinetics (TKs) of CLD in growing pigs using both non-compartmental and nonlinear mixed-effects approaches (NLME). In this study, CLD dissolved in cremophor was intravenously administrated to 7 Creole growing pigs and 7 Large White growing pigs (1 mg kg−1 body weight). Blood samples were collected from time t = 0 to time t = 84 days. CLD concentrations in serum were measured by GCMS/MS. Data obtained were modeled using Monolix (2019R). Results demonstrated that a bicompartmental model best described CLD kinetics in serum. The influence of covariates (breed, initial weight and average daily gain) was simultaneously evaluated and showed that average daily gain is the main covariate explaining inter-individual TKs parameters variability. Body clearance was of 76.7 mL kg−1 d−1 and steady-state volume of distribution was of 6 L kg−1. This modeling approach constitutes the first application of NLME to study CLD TKs in farm animals and will be further used for rearing management practices in contaminated areas.

International audience; Gut microbiota is a key contributor to feed use in monogastric species, in particular via the digestion dietary fibres. Molecular techniques are now available to run large studies and decipher the potential of gut microbiota to improve livestock. Studies on human and mice are more advanced: different factors have been demonstrated to influence the gut microbiota composition and functions, including maternal transmission, environment (diet composition and quantity, humidity and heat), age and physiological status. Studies also evaluated if the host controls its gut microbiota. In pigs, chicken and rabbits, microbiota differences between animals of extreme phenotypes within populations, and between lines divergently selected for specific traits, are reported. Other studies reported that some microbiota abundancies are heritable. Linear mixed models have been used to evaluate its contribution to trait variability, or microbiability, with different data (full vs 16S sequencing of gut or faecal contents) and different variance matrices. They showed significant contribution to production traits, reaching more than 30%. However, confounding effects exist, such as the maternal inheritance of the microbiota and the genetic determinism by the host : many studies show reduction of the genetic additive variance, in addition to reduction of the residual variance with microbiability. Specific datasets, testing a given genetic in different environments or using cross-fostering, are used to better understand the relative contribution of each effect (host genetics and microbiota) to the trait variance, and propose solutions to livestock.

Notice à reprendre pas de clé UT au 27 juin 2019; The study aimed at characterizing the management of 27 pig farms in the frame-work of a conservation program of the Creole pig of Martinique. Blood samples were collected on 67 pigs for serological analysis. A multivariate analysis dis-criminated six groups of farms: group 1 (n = 9) consisted of family farms with fewer than three boars and a higher age of replacement of reproducers than the other farms (6.2 vs 5.0 years, p < 0.01); group 2 (n = 5) consisted of small farms with two matings per sow per yearand with more than two livestock species; group 3 (n = 5) consisted of farms with more than four boars and more than four sows, with batch management and a feeding diet mainly based on industrial concentrates; group 4 (n = 4) consisted of family farms with pigs reared outdoors and a feeding diet mainly based on local resources (50 to 100% of the total diet content); group 5 (n = 3) consisted of mixed farming systems with more than three boars and more than 10 sows; and group 6 consisted of a farm with a high number of females without batch management. The analysis of serological data showed that, regardless of the farming system (outdoor, semi outdoor, indoor), the sanitary status of pig farms in Martinique was good, with no identified con-tagious disease. The typology obtained and the results on the sanitary status of farms are encouraging signs to pursue the project aiming at the conservation of Creole pigs by exchange of healthy reproducers between farmers and the devel-opment of a niche market around heritage values.

espanolLa clasificacion de las razas animales segun su nivel de peligro en cuanto a su desaparicion es un elemento de base para un sistema nacional de alerta y de monitoreo de los recursos geneticos. Un enfoque multicriterio ha sido desarrollado para establecer el nivel de peligro de una poblacion animal domestica. En total, se mantuvieron seis criterios: (i) el numero total de hembras reproductoras, (ii) la evolucion de este numero en los cincos ultimos anos, o las cincos generaciones, segun la especie; (iii) la proporcion de cruzamientos; (iv) el tamano efectivo de la poblacion, (v) la organizacion de los criadores y el apoyo tecnico; (vi) el contexto socio-economico. Con el proposito de facilitar la combinacion de estos criterios de tipo diferente, los valores observados fueron convertidos en una escala de 0 (ausencia de amenaza) a 5 (amenaza maxima), la correspondencia entre valores observados y notas siendo especifica por cada criterio. Para cada raza, las notas estan presentadas de forma grafica y una nota de sintesis esta calculada como la media de las seis notas. Este metodo ha sido aplicado a 178 razas locales francesas perteneciendo a diez diferentes especies: ganado, ovino, caprino, cerdo, caballo, asno, gallina, pavo, oca, pato comun. Asi se demostro que la mayoria de las razas locales francesas se pueden considerar como en peligro: todas las razas locales de equido y de cerdo, casi la totalidad de las razas locales de aves de corral, alrededor de 80% de las razas locales de ganado o caprinos y la mitad de razas locales de ovinos. Se discute el interes de este metodo para la definicion de estrategias de conservacion et la elaboracion de politicas publicas. EnglishBreed risk status assessment methods are key components of country-based early warning and response systems. In this study, a multiindicator method was developed to assess the risk status of livestock populations. Six indicators were used: (i) the current number of breeding females; (ii) the change in the number of breeding females over the last 5 years or generations (depending on the species); (iii) percentage of cross-breeding; (iv) effective population size; (v) breeders organization and technical support; and (vi) socio-economic context. To make these indicators comparable, observed values were converted into scores on a six-point scale (from 0 = no threat to 5 = maximum threat); a specific conversion method was used for each indicator. For each breed, the different scores were analysed graphically and an overall score was calculated by averaging the six separate indicator scores. This approach was applied to 178 French local breeds, belonging to ten different species: horse, donkey, goat, pig, chicken, turkey, goose and Pekin duck. A large percentage of local breeds were found to be at risk to be lost for farming, although the results were species dependent. All local equine and pig breeds, as well as almost all local poultry breeds appeared to be endangered. About 80 percent of local goat and cattle breeds, and half local sheep breeds were also found to be at risk. The usefulness of this method with regards to conservation strategies and public policy is discussed francaisLa classification des races animales selon leur statut vis-a-vis d’un risque de disparition est un element-clef d’un systeme national d’alerte et de suivi des ressources genetiques. Une approche multi-indicateurs a ete developpee pour etablir le degre de menace d’une population animale domestique. Au total, six indicateurs ont ete retenus : (i) le nombre total de femelles reproductrices, (ii) l’evolution de ce nombre dans les cinq dernieres annees, ou generations, selon l’espece ; (iii) la proportion de croisement ; (iv) la taille efficace de la population ; (v) l’organisation des eleveurs et l’appui technique ; (vi) le contexte socio-economique. Afin de faciliter la combinaison de ces indicateurs de nature differente, les valeurs observees sont converties sur une echelle de 0 (absence de menace) a 5 (menace maximale), la correspondance entre valeurs observees et notes etant specifique de chaque indicateur. Pour chaque race, les notes sont representees de facon graphique et une note de synthese est attribuee en calculant la simple moyenne des six notes. Cette methode a ete appliquee a 178 races locales francaises appartenant a dix especes differentes : cheval, âne, bovins, ovins, caprins, porc, poule, dinde, oie, canard commun. Il a ete ainsi montre que la plupart des races locales francaises peuvent etre considerees comme menacees : toutes les races locales d’equides et de porc, la quasi-totalite des races locales de volailles, environ 80% des races locales bovines ou caprines, et la moitie des races locales ovines. L’interet de cette methode pour la definition de strategies de conservation et l’elaboration de politiques publiques est discute.

International audience; Agroecological farming practices require a change in the evaluation and management of plant and animal resources. The goal is to increase the feed self-sufficiency of farms to reduce the negative environmental footprint linked to imported feed. There is a very large diversity of potentially valuable biomass for livestock. The profile of available feeds depends on the characteristics of farms, that is livestock farm versus mixed crop-livestock farm. Whatever the degree of farm specialisation, plant resources should be adapted to soil and climatic conditions in order to reduce inputs such as water, fertilisers and pesticides. Dual crops, that is food and feed, are strategic resources. In mixed farming systems, co-products from these dual crops should be valued as a first step before the incorporation of specialised feeds in the livestock diet. The choice of feeds, as well as the cultures, must be reasoned upon several criteria: multi-functionality, feed value, and environmental impact. A major principle of agro-ecology is the use of animal species and genotypes adapted to their environmental conditions rather than adapting breeding conditions regarding livestock susceptibility. This contributes to the survival of animals and their welfare, their overall productivity, and the reduction of inputs. The choice of animal species should be conditioned by the characteristics of the biomass available on the farm and the greater or lesser efficiency of the species regarding this biomass. A compromise between productivity and adaptation capacity is then required. Within a species, the choice of genotype will depend on its adaptation to the different potential stresses of the humid tropical environment, such as temperature, humidity, diseases and feed quality. In an agroecological approach, qualities required of the right animal include: acceptability to farmers; adaptation to environments including climatic, nutritional and management; resistance to the common diseases of the area; and good reproductive and growth performances.

A specific breeding goal definition was developed for Creole goats in Guadeloupe. This local breed is used for meat production. To ensure a balanced selection outcome, the breeding objective included two production traits, live weight (BW11) and dressing percentage (DP) at 11 months (the mating or selling age), one reproduction trait, fertility (FER), and two traits to assess animal response to parasite infection: packed cell volume (PCV), a resilience trait, and faecal worm eggs count (FEC), a resistance trait. A deterministic bio-economic model was developed to calculate the economic values based on the description of the profit of a Guadeloupean goat farm. The farm income came from the sale of animals for meat or as reproducers. The main costs were feeding and treatments against gastro-intestinal parasites. The economic values were 7.69€ per kg for BW11, 1.38€ per % for FER, 3.53€ per % for DP and 3 × 10(-4)€ per % for PCV. The economic value for FEC was derived by comparing the expected profit and average FEC in a normal situation and in an extreme situation where parasites had developed resistance to anthelmintics. This method yielded a maximum weighting for FEC, which was -18.85€ per log(eggs per gram). Alternative scenarios were tested to assess the robustness of the economic values to variations in the economic and environmental context. The economic values of PCV and DP were the most stable. Issues involved in paving the way for selective breeding on resistance or resilience to parasites are discussed.

En zones difficiles, la pérennité des systèmes d’élevage repose sur la capacité des animaux à survivre, se reproduire et maintenir un niveau de production en situation de fortes contraintes. Les principales contraintes auxquelles les animaux doivent faire face en régions chaudes, sont le climat (température et humidité), la sous-nutrition et les pathologies. Chez les monogastriques comme chez les ruminants, les caractéristiques anatomiques et le comportement alimentaire constituent les principaux facteurs de régulation des échanges thermiques. L’élément clé de l’adaptation comportementale des ruminants à la sous-alimentation est leur capacité à choisir leur alimentation. L’adaptation physiologique porte sur la réduction du métabolisme basal, l’efficience digestive, la valorisation de fourrages grossiers, la mobilisation des réserves corporelles, le recyclage des nutriments et la valorisation efficiente de l’eau. Les travaux les plus significatifs sur la résistance génétique aux maladies portent sur la trypanotolérance, la résistance aux maladies transmises par les tiques et les strongyloses gastro-intestinales. Dans l’élevage moderne, la gestion de ces contraintes environnementales doit se concevoir de façon intégrée. Différentes techniques d’alimentation, de prophylaxie, de gestion d’ambiance des bâtiments d’élevage doivent être combinées pour garantir durablement la pérennité des systèmes d’élevage. Cependant, l’efficacité de cette approche intégrée repose également sur le potentiel adaptatif des animaux pour répondre aux pratiques mises en œuvre. Le développement des productions animales en régions chaudes ne pourra être garanti sans l’utilisation de l’adaptation naturelle des populations animales ou pour le moins, sans inclure les caractères d’adaptation dans les objectifs de sélection des races locales ou spécialisées., The question of adaptation of animals to the tropical environment has become a major challenge for the livestock sector and the scientific community. In harsh areas, the sustainability of farming systems is based on the ability of animals to survive, reproduce and maintain productivity under climatic, food or health constraints. In monogastrics and ruminants, the anatomical characteristics and feeding behavior are key factors regulating heat exchanges (small-size, decrease in subcutaneous fat mass, reduction in feed intake and physical activity). Level of basal metabolic rate, digestive efficiency, ability to utilize lower quality feeds, body reserves mobilization, nutrient recycling and water use efficiency are the main physiological traits of adaptation to underfeeding in ruminants. The most significant works on disease genetic resistance relate to trypanotolerance in African livestock, resistance to ticks or tick-borne diseases like heartwater and resistance to gastrointestinal strongyles. In modern farming systems, management of these environmental constraints must be considered in an integrated framework. Various feeding, environment and health management practices must be combined to reduce risk and maximize productivity. However, sustainable development of livestock production in tropical areas cannot be guaranteed without using the adaptation traits of native animal populations or at least without including adaptation traits in selection program for local and exotic breeds.

International audience; We evaluated the effect of heat challenge on cell viability, concanavalin A-induced proliferation and heat shock protein (HSPs) mRNA expression in peripheral mononuclear blood cells (PBMC) isolated from Creole (CR) and Large White (LW) pigs. The PBMCs were cultured for 9 h at 37°C before being subjected to heat challenge: (1) at 42°C or 45°C for 2, 4, 6 and 9 h to monitor cell viability;(2) at 45°C for 2 and 9 h followed by stimulation for 24 h at 37°C with concanavalin A to evaluate mitogen-induced proliferation; and (3) at 45°C for 3, 6 and 9 h to measure induction of HSP70.2 and HSP90 mRNA. Cell viability was affected by breed and temperature (P

International audience; High ambient temperature (T) is one of the most important climatic factors influencing pig performance. Increased T occurs sporadically during summer heat waves in temperate climates and year round in tropical climates. Results of published experiments assessing the effects of high T on pig performance are surprisingly variable. Thus, a meta-analysis was performed to aggregate our knowledge and attempt to explain differences in the results across studies on the effect of increased T on ADFI and ADG in growing-finishing pigs. Data for ADFI and ADG were extracted from 86 and 80 trials, respectively, from articles published in scientific journals indexed in PubMed, Science Direct, and from proceedings of scientific meetings through November 2009. Data on ADFI and ADG were analyzed using a linear mixed model that included the linear and the quadratic effects of T and BW, and their interactions as continuous, fixed effects variables, and the trial as a random effect factor (i.e., block). In addition, the effects of housing type (2 levels: individual and group housing) and the year of publication (3 levels: 1970 to 1989, 1990 to 1999, and 2000 to 2009) on the intercept and the linear regression term for T (i.e., the slope) were also tested. Results showed that high T had a curvilinear effect on ADFI and ADG and that this effect was more pronounced in heavier pigs. Across T, ADFI was less when pigs were group-housed. The intercept and the regression coefficient (slope) for T were significantly affected by the year of publication. The effect of increased T was greater in more contemporary works, suggesting that modern genotypes could be more sensitive to heat stress than older genotypes of lesser growth potential. In conclusion, pig performance decreases at an accelerating rate as T is increased. The large between-study variability on the effects of high T on pig performance is partially explained by differences in pig BW and to a lesser extent by the year the study was published.

National audience; Despite many challenges faced by animal producers, including environmental problems, diseases, economic pressure, and feed availability, it is still predicted that animal production in developing countries will continue to sustain the future growth of the world’s meat production. In these areas, livestock performance is generally lower than those obtained in Western Europe and North America. Although many factors can be involved, climatic factors are among the first and crucial limiting factors of the development of animal production in warm regions. In addition, global warming will further accentuate heat stress-related problems. The objective of this paper was to review the effective strategies to alleviate heat stress in the context of tropical livestock production systems. These strategies can be classified into three groups: those increasing feed intake or decreasing metabolic heat production, those enhancing heat-loss capacities, and those involving genetic selection for heat tolerance. Under heat stress, improved production should be possible through modifications of diet composition that either promotes a higher intake or compensates the low feed consumption. In addition, altering feeding management such as a change in feeding time and/or frequency, are efficient tools to avoid excessive heat load and improve survival rate, especially in poultry. Methods to enhance heat exchange between the environment and the animal and those changing the environment to prevent or limit heat stress can be used to improve performance under hot climatic conditions. Although differences in thermal tolerance exist between livestock species (ruminants > monogastrics), there are also large differences between breeds of a species and within each breed. Consequently, the opportunity may exist to improve thermal tolerance of the animals using genetic tools. However, further research is required to quantify the genetic antagonism between adaptation and production traits to evaluate the potential selection response. With the development of molecular biotechnologies, new opportunities are available to characterize gene expression and identify key cellular responses to heat stress. These new tools will enable scientists to improve the accuracy and the efficiency of selection for heat tolerance. Epigenetic regulation of gene expression and thermal imprinting of the genome could also be an efficient method to improve thermal tolerance. Such techniques (e.g. perinatal heat acclimation) are currently being experimented in chicken.

National audience

International audience; The aim of this study was to evaluate the effect of a milling by-product diet and two sugar cane diets on the local Creole pig breed (CR). A total of 48 CR pigs (24 females and 24 castrated males) were randomly assigned to four different groups of 12 animals. Pigs were allotted to one of 4 dietary treatments: fed with a control soya-bean meal-corn diet containing 19.1% crude protein (CP) and 15.4 MJ DE/kg (diet 1), with an experimental milling by-product diet (soya-bean meal and wheat by-products) containing 19.4% CP and 13.0 MJ DE/kg (diet 2), with ground cane stalks (GCS) or with fresh sugar cane juice (SCJ). Both GCS and SCJ were supplemented with soya-bean meal complement (400 g/d of a 48.7% CP and 16.1 MJ DE/kg diet) in order to obtain diets 3 and 4, respectively. Pigs were fed close to ad libitum level and had free access to water. All the pigs were slaughtered at 65 kg BW. Between 30 and 65 kg BW, growth performance was significantly (p

Une exploitation agricole produisant à la fois des porcs et des ruminants et des cultures de canne à sucre a été modélisée. L’objectif a été d’optimiser l’utilisation de la canne à sucre comme ressource principale pour l’alimentation animale. Ce modèle se focalise donc sur la production animale. On considère dans ce modèle les flux de matière et d’énergie générés par l’atelier de production depuis la disponibilité de l’aliment jusqu’à la sortie des effluents. Afin de simplifier le modèle, l’élevage se limite à des ateliers d’engraissement dont la taille est variable selon les scénarios étudiés. Deux scénarios ont été étudiés qui sont fonction de la forme de distribution de la canne à sucre pour les porcs (canne broyée vs. jus de canne). Le modèle de prédiction du bilan zootechnique (taille du cheptel, quantité de viande produite) a été développé et validé à partir de la bibliographie et des expériences menées en station expérimentale et chez l’agriculteur. Cette étude préliminaire fait ressortir une alternative intéressante de valoriser la canne à sucre dans une démarche de diversification intégrée.

Participation scientifique et technique de : Xavier Xande, Jean-Luc Gourdine, David Renaudeau, Edourd Despois, Caroline Anaïs, Ode Coppry, Jérôme Fleury, Maurice Mahieu, Maryline Boval, Gisèle Alexandre, Rémy Arquet, Eliel Gonzales-Garcia; National audience; Ce « guide à l’usage des éleveurs » a pour objectif de donner des repères sur l’utilisation d’aliments non conventionnels, adaptés à la diversité des situations de chaque exploitation agricole. Les pratiques doivent être ajustées en fonction des réalités des exploitations agricoles et de l’évolution des connaissances. Ce guide propose des repères sur des utilisations possibles de la Canne à Sucre entière et ses co-produits (Bagasse, Pailles, Amarre, Jus, Mélasse) en Alimentation Animale (Porcs et Ruminants). Cette première version n’est volontairement publiée qu’en 1000 exemplaires (500 en version française, 500 en version anglaise). La seconde version sera enrichie par les remontées de terrain. Ce guide est issu de la synthèse de travaux de recherche d’accompagnement réalisés dans le cadre de 3 projets conduits par l’INRA : Appui au Secteur Elevage de la Martinique 2001-2006 (Fonds FEOGA et Région Martinique) ; Elevage Alternatif 2001-2006 (Fonds FEOGA et Région Guadeloupe) ; Interreg Caraïbe Valorisation de la Canne en Alimentation Animale (Fonds régional de Coopération Guadeloupe, Fonds FEDER, Régions Guadeloupe Martinique et Guyane). Que nos financeurs trouvent ici une matérialisation de leurs investissements pour le développement. En plus des expérimentations conduites, ces projets ont permis de mobiliser des experts mondiaux sur l’utilisation de la canne à sucre en alimentation animale. Leur expérience a aussi été mise à profit dans ce guide tout en essayant de rester dans le contexte de nos agricultures.

International audience; The aim of this study was to analyze post-weaning reproductive performance of Large White sows in relation to season, parity and their lactation performance under tropical conditions in Guadeloupe (French West Indies, 16° Lat. N, 61° Long. W.). This work was based on data recorded in the experimental unit of INRA from January 1993 to December 2003. Two seasons were determined a posteriori from climatic parameters recorded continuously in a station close to the experimental unit. Mean ambient temperature was higher during the hot season than the warm season (26°C vs. 24°C) but relative humidity was comparable for both seasons (i.e. 87% on average). Season had a significant effect on all reproductive parameters analyzed. Primiparous sows weaned in the hot season had a higher probability of a prolonged weaning to estrus interval, WEI (odds ratio was 4.1; p2.5, p

The use of chlordecone (CLD), an organochlorine pesticide used in the French West Indies banana fields between 1972 and 1993, resulted in a long-term pollution of agricultural areas. Animals may be exposed to CLD by ingesting contaminated food or environmental matrices (soil, water or plants). This PhD project is integrated in the objective of securing animal sectors against CLD risk.The aims of this thesis are (1) to provide knowledge on distribution and elimination mechanisms of CLD in farm animals and (2) to develop decision support tools to assist local animal sectors. To this end, in vivo experiments were performed in adult ewes and growing pigs. In pigs, two experiments consisting of monitoring serum and fecal elimination kinetics following a single intravenous administration of CLD or CLDOH (chlordecol) were performed. Non-compartmental and compartmental approaches were used to estimate toxicokinetic parameters of CLD and its metabolites from serum kinetics. Faecal kinetics were used to characterize metabolism of CLD and to quantify its faecal excretion. In ewes, these toxicokinetic data were already available in literature, so the objective was to complete them by characterizing CLD distribution. An experiment involving sequentially slaughters during contamination and decontamination phases allowed to characterize the distribution dynamics of CLD. Correlations between concentrations in tissues were established and CLD half-lives in tissues were calculated. The monitoring of fecal kinetics provided additional knowledge on CLD excretion. All toxicokinetic results obtained in ewes were used to develop a physiologically based pharmacokinetic (PBPK) model to predict CLD concentrations in various tissues. This model will be used to develop decision support tools to assist animal sectors in CLD contaminated areas. An in vivo study is being considered in pigs to characterize the dynamics of CLD tissue distribution and thus be able to develop similar tools to those developed in ewes., L’utilisation de la chlordécone (CLD), un pesticide organochloré utilisé dans les bananeraies des Antilles Françaises de 1972 à 1993, a conduit à une pollution durable des surfaces agricoles. En ingérant des aliments ou des matrices environnementales (sol, eau ou végétaux) contaminés, les animaux sont susceptibles d’être exposés à la CLD. Ces travaux de thèse s’intègrent dans l’objectif de sécurisation des filières animales vis-à-vis du risque CLD. Les objectifs de cette thèse sont (1) d’apporter des connaissances sur les mécanismes de distribution et d’élimination de la CLD chez les animaux d’élevage et (2) de développer des outils d’aide à la décision pour accompagner les filières animales locales. Pour cela, des expérimentations in vivo ont été réalisées chez le porc en croissance et la brebis adulte. Chez le porc, deux expérimentations consistant à suivre les cinétiques d’élimination sérique et fécale suite à une administration intraveineuse en dose unique de CLD ou de CLDOH (chlordécol) ont été réalisées. Des approches non compartimentales et compartimentales ont été utilisées pour estimer les paramètres toxicocinétiques de la CLD et de ses métabolites à partir des cinétiques sériques. Les cinétiques fécales ont permis de caractériser le métabolisme de la CLD et de quantifier son excrétion fécale. Chez la brebis, l’ensemble de ces données toxicocinétiques étant déjà disponibles dans la littérature, l’objectif était de les compléter en caractérisant la distribution de la CLD. Une expérimentation impliquant des abattages sériés pendant une phase de contamination et de décontamination a permis de caractériser la dynamique de distribution de la CLD. Des corrélations de concentrations entre les tissus ont ainsi été établies et des temps de demi-vies tissulaires ont été calculés. Le suivi de la cinétique fécale a également permis de compléter les connaissances sur l’excrétion de la CLD. L’ensemble des résultats toxicocinétiques obtenus chez la brebis ont été utilisés pour développer un modèle pharmacocinétique à base physiologique (PBPK) permettant de prédire les concentrations de CLD dans différents tissus. Ce modèle servira de base pour l’élaboration d’outils d’aide à la décision pour accompagner les filières animales dans les zones contaminées par la CLD. Une étude in vivo est envisagée chez le porc pour caractériser la dynamique de distribution tissulaire et ainsi pouvoir développer des outils similaires à ceux construits chez la brebis.

Dans un premier temps, l’effet de deux environnements climatiques (tempéré, TEMP vs. tropical humide, TROP) sur les performances de production et les réponses thermorégulatrices des porcs en croissance a été évalué. Pour ce faire, un dispositif familial a été produit entre des porcs Large White (LW), sensibles à la chaleur, et des porcs Créole (CR) plus thermotolérants. Dix verrats F1 LW x CR ont été croisés avec 65 truies LW apparentées dans chaque environnement afin d’obtenir 1 298 animaux backcross (TEMP : n=634 porcs issus de 11 bandes; TROP : n=652 animaux issus de 12 bandes). Des pesées ont été réalisées tous les 15 jours de la 11ème à la 23ème semaine d’âge, et des épaisseurs de lard dorsal (ELD) ont été mesurées aux semaines 19 et 23. L’ingéré a été enregistré de 11 à 23 semaines d’âge. Le GMQ, la consommation journalière (CMJ) et l’indice de consommation (IC) ont été estimés. La thermotolérance a été évaluée via des mesures de température cutanée (TC, semaines 19 et 23) et rectale (TR, semaines 19, 21 et 23). Le calcul de l’index THI, combinant les effets de la température et de l’hygrométrie, montre une différence de 2.4°C entre TEMP et TROP. Le GMQ et la CMJ en TEMP sont plus élevés qu’en TROP (830 vs. 754 g/j et 2,20 vs. 1,80 kg/j, respectivement; P

Master