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Master; Le présent document est le résultat d’un travail de recherche réalisé entre le mois de février et le mois de juillet 2017. Ce stage a été réalisé au sein de l’équipe du Centre de recherche en Gestion (CRG) de l’Ecole Polytechnique et de l’Unité de Recherche Mixte Sciences Action Développement – Activités Produits Territoires (UMR SAD-APT) de l’Institut Nationale de Recherche en Agronomie (INRA). L’étude tend à analyser des constructions sociales territoriales diverses autour des problèmes de qualité de l’eau pour identifier des freins et leviers organisationnels et émettre des recommandations à l’ONEMA et aux parties prenantes de la problématique de l’eau en France. Les résultats de cette recherche seront à cet effet, intégrés dans le projet collaboratif ONEMA PACS-AAC (Pression agricole et Coordinations socioéconomiques sur les Aires d’Alimentation et de Captage). La problématique de recherche est d’identifier des freins et des leviers organisationnels des actions collectives volontaires permettant de gérer des problèmes de pollution de l’eau. Pour y parvenir, une étude compréhensive (Dumez, 2016) permettant de décrire et d’analyser d’un point de vue historique plusieurs cas, a été réalisée. Cette étude a été menée selon une démarche abductive combinant une recherche bibliographique et des enquêtes sociologiques. Les résultats de cette démarche prennent la forme de narration (Dumez, 2016). L’analyse bibliographique a consisté à recueillir, analyser et catégoriser les documents portant sur les cas sélectionnés, quatre au total. Les enquêtes sociologiques ont pris la forme d’une série d’entretiens semi-directifs avec des acteurs locaux. Ainsi, quatre narrations ont été réalisées pour chaque cas sélectionné, à savoir, les Sources du Vivier dans les Deux-Sèvres, les Sources du Robec en Seine Maritime, le bassin Versant de l’Aber Wrac’h dans le Finistère et le Champ Captant des Hauts-Près dans la Seine Eure. On les trouve dans la partie Résultat de ce document. Puis, dans la partie discussion, une analyse intra et inter cas a permis de mettre en évidence 4 leviers et 3 freins de l’action collective volontaire. La mise en place d’actions trans-agricoles adressées à un large public (pas seulement aux agriculteurs), l’usage d’artéfact (objet matériel ou virtuel permettant la coordination entre les acteurs), le développement des filières avales pour les produits issus d’une agriculture respectueuse de l’environnement et le respect du temps de réponse des sols dans l’élaboration des programmes d’action semblent faciliter la mobilisation des acteurs locaux et particulièrement de l’acteur clé dans ces démarches de préservation de la qualité de l’eau ; les agriculteurs. A l’inverse, une asymétrie de pouvoir entre les acteurs décisionnaires des programmes d’action, la mise en place de mesures obligatoires (règlementation) et l’usage d’outil incitatif financier semblent freiner la mobilisation voir la rendre « fictif » (pas d’engagement des acteurs par conviction).

International audience; Sensory perception begins before birth and enables us to interpret the biological relevance of stimuli in our near environment. In early life, the senses play a crucial role in informing acceptance and rejection of foods and beverages. Food preferences develop with experience based on associations formed between a foods flavour and the consequence of its consumption. In adulthood the role of the chemical senses is often simplified into simple 'likes' and 'dislikes', but recent evidence highlights a more functional role in guiding eating behaviours and nutrition. A food’s perceptual properties are important for the detection of its nutrient content and through this, guide not only food choice but also habitual energy selection and consumption behaviour. As we age and the prevalence of chronic disease increases, sensory acuity often declines for taste, smell and texture perception, and this can have an impact on food perception, preference and food intake. This creates an opportunity to apply an understanding of sensory influences on choice and intake to stimulate appetite during periods where nutrient intakes may become compromised. This paper summarises current knowledge of the changing role of the senses during infancy and early childhood, through to adulthood, older age and illness. The aim is to highlight opportunities to improve health and wellness through a better understanding of how sensory factors can influence eating behaviours and nutrition at key time points across the lifespan.

Protected Designation of Origin (PDO) is part of the regulated quality schemes in the European Union (EU). Producers of PDO food products and wines have to present EU authorities a technical specification of their product, which includes its sensory description. European regulation 1151/12 establishes that sensory characteristics included in PDO certification must be guaranteed. Nevertheless, there is no standardized approach for the development of sensory control methods for PDO food products, so each entity in charge of controlling the characteristics of the PDO products decides the best way to follow this legal requirement. This paper presents the current situation in Spain, Italy and France in relation to the official sensory control of PDO food products and wines and the accreditation of the laboratories for this control (these three countries represent 68.9% of the total PDO products registered in the EU). This manuscript also shows the main methodologies applied in the official sensory control of PDO food products and wines. The wide diversity of methods used for the sensory control and associated panel management among PDOs manifests the need to harmonize technical criteria and references at European level. This is also urgent, because broad differences in the approaches and requirements for sensory control could bring about unfair competition among PDOs. In this sense, European Sensory Science Society (E3S) has become an EA recognized stakeholder collaborating in a framework in order to prepare a document for the harmonization of methodological approaches and technical criteria for the sensory control of PDO food products and wines.

open access article; International audience; [u]Background & Aims[/u] Malnutrition in older adults results in significant personal, social, and economic burden. To combat this complex, multifactorial issue, evidence-based knowledge is needed on the modifiable determinants of malnutrition. Systematic reviews of prospective studies are lacking in this area; therefore, the aim of this systematic review was to investigate the modifiable determinants of malnutrition in older adults. [u]Methods[/u] A systematic approach was taken to conduct this review. Eight databases were searched. Prospective cohort studies with participants of a mean age of 65 years or over were included. Studies were required to measure at least one determinant at baseline and malnutrition as outcome at follow-up. Study quality was assessed using a modified version of the Quality in Prognosis Studies (QUIPS) tool. Pooling of data in a meta-analysis was not possible therefore the findings of each study were synthesized narratively. A descriptive synthesis of studies was used to present results due the heterogeneity of population source and setting, definitions of determinants and outcomes. Consistency of findings was assessed using the schema: strong evidence, moderate evidence, low evidence, and conflicting evidence. [u]Results[/u] Twenty-three studies were included in the final review. Thirty potentially modifiable determinants across seven domains (oral, psychosocial, medication and care, health, physical function, lifestyle, eating) were included. The majority of studies had a high risk of bias and were of a low quality. There is moderate evidence that hospitalisation, eating dependency, poor self-perceived health, poor physical function and poor appetite are determinants of malnutrition. Moderate evidence suggests that chewing difficulties, mouth pain, gum issues co-morbidity, visual and hearing impairments, smoking status, alcohol consumption and physical activity levels, complaints about taste of food and specific nutrient intake are not determinants of malnutrition. There is low evidence that loss of interest in life, access to meals and wheels, and modified texture diets are determinants of malnutrition. Furthermore, there is low evidence that psychological distress, anxiety, loneliness, access to transport and wellbeing, hunger and thirst are not determinants of malnutrition. There appears to be conflicting evidence that dental status, swallowing, cognitive function, depression, residential status, medication intake and/or polypharmacy, constipation, periodontal disease are determinants of malnutrition. [u]Conclusion[/u] There are multiple potentially modifiable determinants of malnutrition however strong robust evidence is lacking for the majority of determinants. Better prospective cohort studies are required. With an increasingly aging population, targeting modifiable factors will be crucial to the effective treatment and prevention of malnutrition.

National audience

51. Journées de la Recherche Porcine, 5 et 6 février 2019, Paris, p. 309-314,; Intérêt des performances de truies croisées pour la sélection en race pure de caractères de reproduction de la lignée maternelle Large-White. 51. Journées de la Recherche Porcine

International audience; Grain-legume plants fix atmospheric nitrogen in the soil and thus do not need nitrogen fertilizers. Therefore, grain- legumes can potentially decrease global warming, as nitrogen fertilization is responsible for half of all agricultural greenhouse gas emissions. Moreover, grain-legumes have many functional and nutritional properties both as feed and food. Despite the fact that the European Union has granted considerable subsidies to promote grain-legume cultivation, their production continues to fall and there has been no satisfactory explanation as to why. This study provides an answer by showing that a situation of technological lock-in has resulted from the co-evolution of crop systems, based on an agrochemical paradigm, public policies, and market dynamics that promote cereals. This process began with the historical choice by European and French public institutions to relegate grain-legumes to feed in direct competition with imported soybeans. Moreover, interrelated factors, such as breeding selection, public subsidies, and food systems, have favored increasing returns to adoption for cereals to the detriment of grain-legumes. Finally, the evolutionary economics approach used here identified several actions that must be implemented together, such as agricultural cost-accounting methods, nitrogen management, institutional innovations, and market out lets to promote grain-legumes and move towards more sustainable agriculture.

The fatty acid composition of milk determines its nutritional value and health effects. In this study, we collected samples of organic milk during the winter in locations across France and then determined the relationship between animal diet and milk fatty acid composition. The samples contained relatively high percentages of saturated fatty acids (mean: 33% C16:0). Levels declined in March, which shows that allowing animals to graze, even when they have access to silage, improves the nutritional quality of their milk. The samples formed 3 groups based on their nutritional quality, and the groups displayed dietary differences. Milk quality was highest when cows had consumed a winter ration containing faba bean and a greater proportion of grass. Milk quality was lesser when cows who had consumed winter rations composed of maize- and grass-based silage or grain-based silage. No link could be identified between animal diet and individual milk samples.; La composition en acides gras du lait est déterminante pour sa valeur nutritionnelle et ses effets sur la santé. L'alimentation à l'herbe, importante en élevage biologique, assure un bon équilibre entre les divers acides gras. Qu'en est-il pour les laits biologiques produits en hiver ?Les profils en acides gras de laits biologiques collectés dans toute la France en hiver ont été déterminés et confrontés au type d'alimentation des animaux. La teneur de ces laits en acides gras saturés est relativement élevée (33 % en moyenne de C16:0) ; elle baisse en mars, confirmant que la mise à l'herbe, même avec un silo maintenu ouvert, améliore la valeur nutritionnelle du lait. Trois groupes ont pu être identifiés à partir de la qualité des laits collectés par la laiterie et un lien établi avec l'alimentation : la ration hivernale comportant le plus d'herbe avec des apports de féverole, est plus favorable que celles basées sur les ensilages de maïs et d'herbe ou de céréales. Aucun lien n'a pu être identifié entre les prélèvements de lait individuel et l'alimentation.

International audience; Purpose : Improving the environmental performances of viticulture practices is particularly complicated during unfavorable climatic conditions because of the need for fungal and other pest pressure and the variability of phytosanitary control methods available for winegrowers. However, winegrowers wish to improve the environmental performances of their practices regardless of climatic conditions. The objective of the study was to quantify the variability in environmental impacts due to climatic variations, and changes in viticulture practices induced by climatic variability. Methods : Life cycle assessment was used to evaluate the environmental impacts of viticulture technical management routes (TMR) implemented on five plots in the Loire Valley for the Chenin Blanc grape variety. These TMRs are representative of the range of practices used in the region, including intensive conventional practices to moderate organic practices. The study covered two different years of production (2011 and 2013) under contrasting climatic conditions. The first year (2011) was hot and dry, which are favorable conditions for viticulture, while the second year (2013) was cold and humid, which are unfavorable conditions. Results and discussion : During the unfavorable year, the number of phytosanitary treatments and soil maintenance interventions increased for most of the studied TMRs. This meant that the inter-annual variability in environmental impact was significant, depending on the type of TMR, with differences in impacts ranging from 19% to more than 40% between 2011 and 2013. Managing environmental impacts was found to be more difficult for the organic systems when climatic conditions are unfavorable (in 2013). The non-organic TMRs showed less variation in environmental impacts than the organic TMRs between the 2 years studied. Conclusions : This study shows the importance of taking into account inter-annual variability in environmental assessments of viticulture systems. Indeed, winegrowers do not respond the same way to climate variability mainly with regard to plant protection and soil maintenance. Viticulture is very sensitive to inter-annual climate variations due to the parasitic pressure variability. The different production systems do not give to winegrowers the same possibilities for adapting practices to limit their impact on the environment.

Ce volume regroupe les textes issus du programme Casdar "Innovation et Partenariat" et "Recherche finalisée et innovation" de 2013. Le colloque de restitution s’est déroulé le 6 février 2019 sous l’égide du GIS Relance Agronomique; The AcID (acidosis and diagnosis indicators) project was funded by CasDar and began in January 2014.The aim of the project was to use milk fatty acids profile to predict ruminal fermentations and subacuteruminal acidosis (SARA). The estimation of milk fatty acids profiles in routine using mid infrared (MIR)spectroscopy coupled with field surveys were supposed to make it possible to calculate SARA frequency in dairy cows herds and dairy goats flocks. This method was also supposed to make itpossible to identify sensitive animals and risky feeding practices, and to evaluate the effects of SARA onanimal health and milk production. In dairy cows, a curvilinear relationship between even to odd fattyacids ratio in milk and ruminal acetate to propionate (C2/C3) ratio has been brought to light. Milk MIRspectra were used to build an equation to estimate C2/C3 ratio in routine with quite good precision (R² =0.82). In dairy goats, no relationship between milk fatty acids and ruminal fermentation parameters hasbeen highlighted, and the estimation of fermentation parameters directly from MIR spectra was notprecise enough. A case-control survey was led in 60 dairy cows herds which were recruited on the basisof their milk fatty acids profile and fat to protein ratio. 94 field surveys were conducted in dairy goatsflocks on the basis of their feeding practices. Results from the surveys are similar between species: veryfew SARA cases were observed or suspected, the feeding practises identified as risky were alreadyknown, and the strategy used to prevent SARA is working quite well.; Le projet CasDar AcID (acidose et indicateurs pour le diagnostic) a débuté en janvier 2014. Son objectifétait d’utiliser le profil en acides gras (AG) du lait comme prédicteur des paramètres fermentaires durumen et donc de l’acidose ruminale subaiguë (ARSA) chez la vache laitière et la chèvre laitière. Laquantification de ces profils en routine par spectrométrie moyen infrarouge (MIR) devait permettre, viades enquêtes en élevage, d’estimer la fréquence de l’ARSA dans les troupeaux, d’identifier les animauxles plus sensibles et les pratiques alimentaires à risque, et d’évaluer les effets de l’acidose sur la santédes femelles et leurs performances de production. Chez la vache laitière, le projet a permis de mettreen évidence une relation curvilinéaire entre un ratio d’AG pairs/AG impairs du lait et le rapport acétatesur propionate (C2/C3) du jus de rumen. Une équation spécifique a été développée à partir desspectres MIR afin de pouvoir estimer ce rapport en routine, avec une précision satisfaisante (R² = 0.82).En chèvres laitière, aucune relation nette entre les AG du lait et les paramètres fermentaires du rumenn’a été mise en évidence, et l’estimation directe des paramètres fermentaires par spectrométrie MIR n’apas été concluante. L’enquête en élevage a été de type cas / témoin en bovins où 60 troupeaux ont étérecrutés sur la base du profil en AG du lait et du ratio TB/TP (Taux Butyreux/Taux Protéique). Encaprins, 94 enquêtes ont été valorisées dans des élevages recrutés sur la base de leur conduitealimentaire. Les résultats de ces enquêtes convergent entre espèces : le faible nombre de cas d’ARSAobservés ou suspectés dans les troupeaux enquêtés confirment les facteurs de risques déjà connus, etmontrent que la stratégie de prévention de l’ARSA encouragée dans les élevages fonctionne.

International audience; Consumer demand and state incentives in certain EU countries are driving the rapid development of organic viticulture. However, compared with conventional viticulture, it has shown higher interannual variability in its environmental impacts. Improved understanding of this variability would help organic winegrowers better address their environmental impacts.This two-part study examined interannual variability of environmental impacts of four vineyards with contrasting pedoclimatic and technical production conditions. First, life cycle assessments were performed on each of these four vineyards for two contrasted years in terms of both climate and pest and disease pressure. Next, for one of these vineyards located in Mediterranean conditions, life cycle assessments were completed on a chronosequence of six consecutive years. Life cycle assessments of organic wine grapes were calculated based on detailed inventories of data from the eight real vineyard situations. Interannual variations were considered to be the deviation between the impact results of two production years. In all the vineyards, diesel combustion was the main impact contributor. For the four vineyards, the impacts that varied most were generally freshwater ecotoxicity, soil ecotoxicity, marine eutrophication, freshwater eutrophication and metal depletion. The intensity/range of interannual variations differed between plots. The main agricultural operations contributing to impact variations were from disease management of climate-related disease pressures. The 6-year chronosequence analysis showed that certain years were very similar in terms of impact results. The impact that varied most was surprisingly terrestrial acidification. The chronosequence analysis brought to light that the choice of active ingredient could be a greater source of impact variations than interannual climatic conditions and disease pressure. This study provides an overview of the hotspots and variability of organic viticulture environmental impacts in contrasted climate years and a climatic chronosequence. The main pathways for environmental performance improvements are (i) reducing fuel consumption by either limiting the number of operations, using more fuel-efficient machines or different energy sources or/and adjusting tractor speed; (ii) reducing the doses and emissions of copper products and choosing the less impacting types of copper; and (iii) limiting nitrogen and heavy metal emissions through the choice of fertiliser type and management.

This study analyses the Mintel’s Global New Product Database. This database makes an inventory of the new dairy products launched from 2016 to 2018 in 62 countries. The database gathers information on the launched products, such as the kind of claims written on the packaging. In a first part, the database and the context of the study are presented (dairy industry around the world, consummers’ demand, definition of the positioning claims). Then, the data is extracted, organised and submitted to correspondence analysis. The study aims, in a first place, to highlight differences in the supply of new dairy products, especially the positioning claims of these products, between markets on a global scale and on an european scale. Secondly, the French products are analysed and compaired to the previous results. In a second step, French products are analysed and compared with previous results, to answer the following question : are dairy products manufactured in France and present on international markets positioned indifferently from the supply trends of the target market, or do they aim to be in line with the characteristic positioning of the target market's supply ? The data extraction allows the construction of contingency tables that count the number of positioning claims identified regarding the different modalities of the variable « geographic area » and « type of positioning claim ». Data are analysed using the correspondence analysis. This type of statistical method highlights the links existing between different modalities. The positioning claims are gathered in ten categories, related to different concepts (based on the Mintel’s pre-categorization), mainly : naturality, convenience, ethical and environmental-friendly claims, compatibility with special food diet such as halal or kosher. The analysis pictures the importance of the allegations that communicate on the low content of chemical compounds (such as additives or preservatives), on every market. Each area has a special kind of positioning : ethic and environmental for Europe, health-relative in Asia with the importance of functional food, « Free From » in North and South America, halal and kosher in Middle-East/Africa. Within Europe, the ethic and environmental positioning is due to the French and North-European demand, whereas the English demand distinguishes itself with the importance of the vegetarian and vegan suitable products. Finally, we can see to a certain extent that French companies are adapting their offer in certain markets to take advantage of these consumer trends.; L’étude s’appuie sur l’analyse de la base de données Global New Product Database de Mintel. Cette base recense les informations relatives aux nouveaux produits mis sur le marché, dont les allégations visibles sur l’emballage des produits. Après la présentation de cette base et des données analysées, des éléments de contexte sont expliqués (marché des produits laitiers mondial et européen ; définition des positionnements étudiés, lien avec la demande des consommateurs). Enfin, les données sont extraites, organisées et soumises à des analyses factorielles des correspondances. Dans un premier temps, le but de l’étude est de mettre en valeur les différences de l’offre entre les marchés, au niveau mondial, puis européen, pour identifier les types d’allégations les plus répandues sur les nouveaux produits laitiers lancés entre 2016 et 2018 sur chaque marché. Dans un second temps, les produits français sont analysés et comparés aux résultats précédents, dans le but de répondre à la question suivante : les produits laitiers manufacturés en France et présents sur les marchés internationaux sont-ils positionnés indifféremment des tendances de l’offre du marché cible, ou bien visent-ils à être en adéquation avec les positionnements caractéristiques de l’offre du marché cible ? L’extraction des données permet la création de tableaux de contingence qui comptabilisent les nombres d’allégations identifiées selon les modalités des variables « zone géographique » et « type de positionnement ». Les données ainsi compilées sont analysées par analyse factorielle des correspondances. Ce type d’analyse permet de visualiser les liens importants entre certaines des modalités. Les dix positionnements étudiés correspondent au regroupement des allégations en classes cohérentes. Ils sont liés à différents concepts : la naturalité, la praticité, le respect de l’environnent ou de valeurs éthiques, la compatibilité avec des régimes particuliers. Une analyse s’est également intéressée à la variable « type de produit » par rapport à la variable « type de positionnement ». Les analyses permettent de visualiser l’importance générale des allégations communiquant sur la teneur réduite de certains composés précis, toutes zones confondues. Elles permettent de relever pour chaque zone des types d’allégations particulièrement présentes (éthiques et environnementales en Europe, « santé » en Asie avec les produits enrichis en molécules actives, compatibles halal et casher au Moyen-Orient/Afrique et « sans » aux Amériques (Nord et Sud). Au niveau européen, c’est surtout l’importance des allégations éthiques et environnementales qui caractérisent l’offre des marchés français et nord-européens, et les produits compatibles aux régimes végétariens et végans en Angleterre. Enfin, on voit dans une certaine mesure que les entreprises françaises adaptent leur offre sur certains marchés pour profiter de ces tendances de consommation.

Despite a constant decline in grassland areas between the 1970s and 2010 at the regional and national scale in France, in particular on lowlands, grasslands have been maintained locally. This raises questions about long-term changes on the farms involved in these dynamics, particularly with regard to the relation between the evolution of the role of grasslands in production processes, and farmers' perceptions of fodder systems within production systems. Our research concerned three peri-urban cantons in Brittany, where we examined grassland practices over the long term and farmers' perceptions of grasslands in a sample of 15 farms within the area where grasslands were maintained. First, we modelled pathways of the place and roles of grasslands on farms, based on criteria of quantitative presence, management, and valorisation. Second, we characterised the farmers' perceptions of grasslands and the fodder system. We then performed combined analysis of these pathways and perceptions. The maintenance of grasslands was found in a diversity of pathways in which grasslands were used to a medium and large extent in the fodder systems. These changes occurred either through a complete redesign of the fodder system or through hybridisation of practices aimed at obtaining dairy systems that were more intensive yet more agri-ecological. The pathways that gave a new place to grasslands in the fodder system were related to farmers' perceptions marked by a fading opposition between grasslands and maize farming. They attributed additional value – in terms of animal welfare, economics, or agronomy – to grasslands in a mixed maize/grassland fodder system.

Master; L’étude développée dans ce rapport portait sur la contribution de l’azote endogène, provenant de l’autolyse enzymatique, à la digestibilité de protéines de sources végétales et animale dans un modèle de digestion in vitro statique. Cette étude a pu être réalisée grâce à l’utilisation de matrices protéiques marquées intrinsèquement à l’azote 15N permettant de différencier l’azote d’origine exogène de l’azote d’origine endogène. Les trois matrices protéiques mises en oeuvre : caséine, gluten et biscotte, ont été soumises à un protocole harmonisé de digestion in vitro et des analyses ont été menées sur la matrices brutes ainsi que sur les digestas. La composition protéique des matrices a été évalué (taux protéique, contenu en acides aminés). Au cours de la digestion, le profil peptidique (distribution de taille), le degré d’hydrolyse, les digestibilités apparente et réelle, ainsi que la proportion d’azote endogène digestible par rapport à l’azote endogène total mis en oeuvre ont été mesurés. La proportion d’azote endogène digestible (< 10 kDa) par rapport à l’azote endogène total mis en oeuvre était de l’ordre de 5,78 ± 0,31 % pour la caséine, 5,46 ± 1,27 % pour le gluten et 4,86 ± 1,01 % pour la biscotte. Pour le gluten, cette proportion diminuait sensiblement avec le taux de protéines alimentaires mis en oeuvre. Il également pu être observé que la surestimation entre digestibilité apparente et réelle pouvait s’élever à plus de 70 % et variait très largement avec le taux de protéines : 73,78 ± 4,15 % pour la caséine à 4 % contre seulement 17,68 ± 0,53 % pour la caséine à 16 %, et le constat est similaire pour le gluten. En parallèle, d’autres données ont pu être acquises notamment concernant les modifications du profil peptidique des digestas par l’ultrafiltration, l’effet du taux de protéines et du temps de digestion sur les différentes données telles que degré d’hydrolyse et digestibilité. Il a pu être observé que l’ultrafiltration à 10 kDa engendrait la perte de jusqu’à plus de 50 % des peptides de la classe de 5 à 10 kDa et donc modifiait sensiblement le profil peptidique des digestas. Le degré d’hydrolyse, la digestibilité apparente et réelle et la part d’azote endogène digestible par rapport à l’azote endogène total varient significativement selon le repas (matrice x taux protéique) et le temps de digestion. On observe systématiquement un effet de la phase de digestion (gastrique vs intestinale). De manière globale, la digestibilité apparente et réelle augmente avec la diminution du taux de protéines mis en oeuvre et la présence de fibres ne semble pas impacter ces digestibilités lorsque l’on compare les données de biscotte et de gluten.De forts coefficients de corrélation entre les digestibilités (apparente et réelle) et le degré d’hydrolyse ont également été montré justifiant le rapprochement souvent faits dans les études de digestion in vitro. CONCLUSIONS Cette étude, qui est la première à estimer l’azote endogène digestible, a permis de démontrer une contribution non négligeable de la part d’azote endogène digestible dans la part d’azote digestible totale, entrainant la surestimation de la digestibilité des matrices d’autant plus importante que le taux de protéines mis à digérer est faible. Alors que le protocole de digestion est aujourd’hui harmonisé, l’estimation de la digestibilité in vitro des protéines varient largement d’un laboratoire à un autre. Il est donc nécessaire de poursuivre les expérimentations pour connaître la nature de cette fraction azotée digestible d’origine endogène. Ainsi, bien que le modèle utilisé (Minekus et al., 2014; Brodkorb et al., 2019) soit « harmonisé », cette dernière n’est pas encore complète. Les différences observées entre digestibilité apparente et réelle ainsi que celles de digestibilité selon les quantités de protéines mises en oeuvre montrent que des erreurs plus ou moins importantes de surestimation de digestibilité subsistent encore pour ce modèle.

International audience; Electrolyzed water (EW) has attracted much recent attention as a high-performance, new technology for its potential use in the food industry. However, the risk of postharvest EW treatments of winegrapes destined for winemaking is the chloroanisoles formation in the final product. In the present study, we investigated the impact of postharvest grape EW and storage treatments on the occurrence of these compounds in wine, 2,4,6-trichloroanisole (TCA) being the main compound responsible for the cork taint off-flavor due to its extremely low perception threshold. The results revealed that the presence of TCA in the wines depended on the concentration of residual free chlorine in the must from the EW treatment. Particularly, TCA was not detected in wine when active chlorine concentrations higher than 0.005 mg/L were present in the must. Chloroanisole and chlorophenol levels in wine were strongly affected not only by EW but also by grape storage conditions (temperature, time, sunlight exposition). The results showed that the 24-hours grape storage at a controlled temperature of 20 degrees C in the dark, after EW treatment, resulted in the highest TCA concentrations in wines (7.3 +/- 2.7 ng/L), while storage and withering in sunlight seemed to mitigate its presence in wine. This could suggest that microbiological formation of chloroanisoles may have been influenced by the storage temperature and germicidal effect of UV light. Biochemical mechanism of chloroanisoles production in grapes and wine is unknown, but the combination of residual free chlorine on the grape surface and the controlled storage conditions in the dark may have positively influenced the bio-formation of chloroanisoles and therefore their presence in wine.

National audience

Adoption of crop diversification is a pillar of agroecological transition (Poux and Aubert, 2018) but faces many barriers, which emerged historically along the specialisation trend of modernisation. These barriers occur at different levels of the agri-food system, reinforce each other and create a situation of socio-technical lock-in (Meynard et al., 2018). They have been described mainly by studies focusing on conventional agriculture, rather oriented to commodity markets and involving temporal diversification (integration of a new crop in the rotation). However, diversification initiatives can involve a wider range of strategies and contexts. Our objective was to investigate whether the presence and conjunction of barriers could be specifically related to some diversification strategies. Developing such understanding would contribute to fine-tune research, innovation and political action in line with the type of crop diversification promoted.

National audience

National audience; One of the challenges in low-input annual arable mixed crops (i.e. species and variety mixtures) is to determine which species / varieties go well together to improve overall system performance. Theories coming from community ecology suggest that two ecological processes are particularly involved in mixed crops performance by improving resource use efficiency [1]. Niche complementarity can be quantified by the distance between target functional traits between two plants. Phenotypic plasticity can be quantified by the variance of target functional traits between cropping environments (including crop management). We aim to apply this ecological theory in an agronomical context by calculating these complementarity and plasticity metrics to predict crop yield of various mixed crops in different environments. A plant trait database on wheat and pea mixtures was built, gathering ten experiments with various management practices over six years, localized in two French sites (Angers, Toulouse). Plant traits were measured dynamically (crop height, aerial biomass, nitrogen content) to quantify crop growth and development over key phenological stages and at harvest (yield, grain quality) to quantify crop performance. Together with environmental (climate and soil) indicators we considered both trait by trait and multi-traits methods to analyze performance variability.

National audience

International audience; Organic viticulture is developing rapidly due to consumers demand and state incentives in some EU countries. Nevertheless, it has shown higher inter-annual variability in its environmental impacts than conventional viticulture. Therefore, the organic winegrowers would benei from a better understanding of this variability in order to better address their environmental impacts. A study was conducted in four contrasted pedoclimatic conditions and two contrasted years in terms of climate and of pest and disease pressure. LCAs of organic wine grape was calculated based on detailed inventories of data from the eight real vineyard situations. Main contributor to impacts was diesel combustion. The inter-annual variation was different between the plots. The impacts that varied the most were teh freshwater and soil eco-toxicities, marine eutrophication, freshwater eutrophication and metal depletion. The main agricultural operations contributing to impact variations were desease management due to climatic conditions variations.

Master; The L-grass model is a model of aerial and root morphogenesis of forage grasses. This model is a Structure-Function type whose simulation time follows an exponential profile as a function of the number of iterations. The aim of this internship is to create meta-models of different parameters of interest describing the agronomic value of grasslands. Metamodels were built according to 2 methods, the first allowing to obtain the variables in a direct way and the second in an indirect way, called "cascade" (waterfall), in order to take into consideration the morphogenesis properties of plants. The metamodels obtained were generally shown to be capable of predicting variables in a range close to the observed values and are also capable of anticipating cut responses. Meta-modelling also made it possible to carry out a diagnosis of the L-grass model.; Le modèle L-grass est un modèle de morphogenèse aérienne et racinaire de graminées fourragères. Ce modèle est de type Structure-Fonction dont le temps de simulation suis un profil exponentiel en fonction du nombre d’itération. Le but de ce stage est de construire des méta-modèles de différents paramètres d’intérêts décrivant la valeur agronomique des prairies. Les méta-modèles ont été construits suivant 2 méthodes, la première permettant d’obtenir les variables de manière directe et la seconde de manière indirecte, dite en « cascade », dont la construction permet de tenir compte des processus de morphogenèses des plantes. Les méta-modèles obtenues se sont dans l’ensemble montrés capable de prédire les variables dans une gamme proche des valeurs observées et sont également capable d’anticiper les réponses à la coupe. La méta-modélisation à également permis de réaliser un diagnostic du modèle L-grass.

International audience; To assist the analysis, assessment and design of agro-ecological cropping systems a conceptualization at farm level is required. This Farm System (FS) is an integrative scale to assess multicriteria performances of cropping systems and their organization in space. We proposed a methodology to guide the conceptualization of an issue (here related to the agro-ecological transition) into a farm system. The output is a conceptual model aimed at sharing knowledge from various sources, organizing a set of indicators for assessing or implementing a numerical model. We have adapted to the FS the method proposed by Lamanda et al., 2012 on the agrosystem at field scale to guide the conceptualization of an issue into an Agrosystem. The conceptualization is based on structure-function analysis that is to say the relations in time and space between the components of the system (nature and organization), the processes (biophysical, technical, socio-economic) and the performances. The originality of the concept of activity to decompose with parcimony the FS. An activity is defined by a type of agricultural product and the technical , biophysical, financial and labor input used for it. Activities are performedon all fields of the "farm territory" (i.e. all pieces of land, including ecological infrastructures included by the farmer in the farm activities). The final product of the methodology is a conceptual model of the FS for the issue to be addressed. The approach has been tested on case studies of agro-ecological vineyard farms. We showed that the methodology to guide conceptualization was appropriate to identify activities with parsimony and at the crossroad of different disciplines. The conceptual model obtained was used to define and calculate a set of indicators of FS performances. In the case study of a farm in conversion to organic farming, four activities in conventional farming and four in organic farming were identified whereas the vineyard regrouped 19 plots. Each activity was qualified by labor requirements and its cost at different periods of the year. We also tested its relevance for life cycle assessment and economic analysis of grape production. Finally we tested the approach to assess strategic decisions related to production factors during transition towards agro-ecological farming. The conceptual model was used to derive a bioeconomic model of the FS based on linear programming and optimization. The methodology of conceptualization of an issue into a Farm System was developed and tested on vineyards farms which are particulary complex in term of combination of activities and fields. The methodology demonstrated its use for sharing knowledge between different disciplines, integrating various results of a project and implementing numerical model for scenario analysis. It provides an operational way to integrate the biophysical, technical and socio-economic dimensions needed to design and manage the agro-ecological transition of farms.

National audience

National audience

National audience; Farmers get more interest in alternative approaches of animal health, whereas much scientists and veterinarians contest their efectiveness. Using a pragmatic theoretical framework, we focus on adoption process of these approaches by farmers. We conceptualize this porcess by alternation of four scenes corresponding to four different types of confrontation between farmers and these techniques : training courses, on farm tests, peers exchange groups and individual consultations. We show that breeders become "amateur" of these alternative approaches : they combine different techniques for animal care, and so, they coordinate their own operations with those of animal health professionals.; Les approches alternatives en santé animale sont devenues courantes dans les élevages, bien que leur efficacité soit contestée par nombre de scientifiques et de vétérinaires. Suivant les principes de la sociologie pragmatique, les auteures ont formalisé le processus par lequel les éleveurs s'approprient ces approches, en reconstituant les quatre scènes au cours desquelles ils s'y confrontent : la formation, l'essai en ferme, le travail en groupe d'éleveurs, la consultation individuelle de spécialistes. Les usages que les éleveurs font de ces approches pour soigner leur troupeau, ce qui implique une coordination entre leurs propres interventions et celles des autres professionnels de santé.

Part of special issue: Abstracts of the 39th ESPEN CongressPart of special issue:Abstracts of the 39th ESPEN Congress; Potentially Modifiable Determinants of Malnutrition in Older Adults: A Systematic Review. 39. ESPEN Congress

WP1Experimental evidences showed the effect of ageing on the capability of elderly in dealing with food, including package opening/handling, sensory discrimination (e.g. differences between autonomous and dependant elderly), biting force etc. Eating capability assessment can be used to choose the food of just-right texture and desired oral processing properties. A set of guidance about food packaging design for elderly and baseline environmental impacts for Optifel systems was established.WP2WP2 produced a software tool for calculating the necessary nutrient composition for the concepts of model products for the given target group (dependent elderlies needing fortified food) upon eating in specified cook-and-serve systems. WP2 also collected the specific needs of the elderlies for nutritional and sensory properties and produced guidelines for the industry. The guidelines give recommendations for nutrients to be fortified and instructions for sensory properties.WP3Food prototypes, based on fruit and vegetables, which met safety and nutritional requirements, food preferences (taste and texture) and constraints for elderly people were prepared using conventional and new technologies. They included soft-solid and liquid concepts enriched with proteins, minerals and vitamins. Industrial scenarios were simulated for production and distribution of the prototypes. A full approach of a week meal was developed under the OPTIFEL TOOL KIT concept.WP4Optifel prototype foods enriched with proteins, vitamins and minerals were characterized for sensory properties, nutritional values, safety, environmental and cost performance. Usage conditions (delivery system, storage, reheating and serving) that maintain protein digestibility, vitamin stability, reduce microbial risk and optimize environmental and cost performance, were identified. New scientific knowledge was obtained on these issues and published.WP5The enriched recipes produced in Optifel project were assessed by autonomous elderly to select the most appreciated one in each product category. Those selected recipes were then tested as part of a full meal (in comparison with non-enriched versions) by elderly living in nursing homes or benefiting from food services. The products were well appreciated and allowed to increase the proportion of elderly reaching a recommended protein intake at lunch.WP6The knowledge produced within the OPTIFEL project was disseminated through an active website (www.optifel.eu), synthetized in guidelines addressing the food and care industries (http://www.optifel.eu/food-for-elderly/guidelines/), and in seminars dedicated to food for seniors, one of them including a culinary demonstration. Further the results were presented in 137 trade fairs, scientific congresses, media (newsletters, interviews, press) and in 27 scientific publications.

Le projet AFB PACS-AAC (Pression agricole et Coordinations socioéconomiques sur les Aires d’Alimentation et de Captage) inclut une étude ayant pour visée l’analyse et la compréhension des freins et leviers organisationnels des actions collectives volontaires permettant de gérer des problèmes de pollution de l’eau. Le présent document est un état d’avancement de cette étude retraçant le travail réalisé en 2016. Via une démarche abductive combinant une recherche bibliographique et des enquêtes sociologiques, une caractérisation de la diversité des actions collectives volontaires est réalisée. Cette caractérisation de la diversité des actions collectives volontaires autour de la gestion de l’eau se traduit par l’identification des critères de distinction et de terrains modèles-types (cas) susceptibles d’être étudiés dans la suite du programme de recherche. L’identification de cette diversité des démarches collectives volontaires dans les territoires peut en outre aider d’autres études à venir pour ce qui est de la construction de l’échantillonnage et du choix des terrains d’étude. Cette caractérisation de la diversité des démarches collectives dans les territoires peut aussi permettre une certaine réflexivité pour les gestionnaires de l’eau et une meilleure prise en compte du contexte organisationnel local.

Dans un contexte de transition agroécologique, le projet Agrinnov a permis de valider un tableau de bord d’indicateurs analytiques de la qualité biologique des sols agricoles permettant aux agriculteurs d’appréhender l’impact de leurs pratiques. Le projet AgrInnov a amené des chercheurs et des agriculteurs à collaborer. En parallèle du tableau de bord (comprenant des indicateurs de faune du sol, de microbiologie et agronomiques), des formations sur la biologie des sols ont été élaborées ainsi qu’un mode opératoire de transfert. Les formations et le tableau de bord ont été déployés sur un réseau national de plus de 250 fermes en grande culture et en viticulture. D’un point de vue scientifique, il a été démontré que moins de 10% des parcelles testées étaient dans un état critique en termes de biologie du sol ce qui est encourageant sur la qualité des sols agricoles, même si il faudrait développer leur surveillance sur un plus grand nombre de fermes et de systèmes de production afin d’avoir un diagnostic plus exhaustif et représentatif. D’un point de vue opérationnel, plus de 97% des agriculteurs ont suivi le projet jusqu’au bout avec un fort investissement de leur part. Par conséquent, le projet AgrInnov a fait la démonstration opérationnelle de l’application et de l’appropriation par les agriculteurs des nouveaux outils de diagnostic de la qualité des sols émanant directement de la recherche, Within a context of agroecological transition, the Agrinnov project validated a set of indicators of the biological quality of agricultural soils to enable farmers to grasp the impact of their practices. AgrInnov project brought researchers and farmers to work together. To accompany the set of indicators of soil fauna, microbiology and agronomy, training sessions on soil biology have also been implemented together with an appropriate transfer procedure. The training sessions and the set of indicators were spread on a national network of more than 250 field-crop and viticulture farms. From an operational viewpoint, more than 97% of the farmers invested heavily in the project and stayed involved throughout Cannavacciulo M. et al. 42 Innovations Agronomiques 55 (2017), 41-54 the project. From a scientific viewpoint, less than 10% of the tested plots were assessed to be in a critical state in terms of soil biology, which is encouraging on agricultural soil quality, even though the monitoring should be developed on a broader number of farms and production systems in order to have a more exhaustive and representative diagnosis. Thus the AgrInnov project demonstrated the application and adoption by the farmers of new research-based tools for diagnosing soil quality.

International audience

Plaquette; Une étude de la gestion de la santé animale par les éleveurs a été menée au printemps dernier, afin de comprendre et détailler les pratiques sanitaires préventives mises en place, notamment pour gérer le parasitisme. Le lien entre ces pratiques et l'environnement de conseil était aussi étudié.

National audience; Organic livestock farmers are looking to improve animal health via alternative global approaches that focus on prevention. Feeding management is one of the main factors influencing herd health. This fact was the basis for the Obsalim (R) method, which was developed by a veterinarian and which relies on detailed observations of livestock. Here, we surveyed farmers to evaluate the method. We determined that its success arises from the efficiency of training (both at the individual and group level) and its effective application by livestock farmers (e.g., during feeding management or ration choice). The specific use of this relatively complex method depends on production objectives. Although Obsalim (R) has not yet been validated by scientific research, it has changed how animals are viewed and seems particularly relevant for grass-focused systems.

Chapitre 4; National audience

Travail présenté au congrès 40th World Congress of Vine and Wine, Sofia, Bulgarie, 29 mai–2 juin 2017; National audience; The evolution of technical management routes (TMRs) towards greater respect for the environment requires an assessment of environmental performances. In the context of sustainable management other factors must be taken into account, as the risk of grape quality changes. Environmental assessment results using the Life Cycle Assessment (LCA) method and the assessment of grape quality are based on numerous data and needs multicriteria decision-making analyzes. This work aims to show the interest of a joint evaluation method “environment and quality”, in the process of change of practices to improve performances. The results obtained on 5 TMRs show a great difference of score between the 2 vintages studied and some practices were identified as having the biggest impact difference. Proposals for modifying practices were tested on a TMR. These theoretical proposals for changing practices improved the final environmental scores from +0.15 points to +0.77 points (/ 10) while studied independently and +2.29 points (/ 10) while combined. A model explaining the quality of grapes using viticultural practices verifies that the proposed new practices don’t present a potential risk for grape quality. The method of joint evaluation CONTRA-QUALENVIC adapted to viticulture shows here that it can be a tool to help improving TMRs.; L’évolution des itinéraires techniques viticoles (ITKv) vers un plus grand respect de l’environnement passe par une évaluation de leurs performances environnementales. Dans un contexte de gestion durable, plusieurs autres facteurs sont à prendre en compte, notamment le risque de modification de la qualité des raisins issus de ces ITKv. Les résultats d’évaluation environnementale par la méthode d’Analyse du Cycle de Vie (ACV) ainsi que l’évaluation de la qualité du raisin s’appuient sur beaucoup données. Ce travail montre l’intérêt d’une méthode d’évaluation multicritère conjointe « environnement et qualité », dans le processus de changement de pratiques pour une amélioration des performances. Les résultats obtenus sur 5 ITKv montrent des différences de notes entre les 2 millésimes étudiés et des pratiques ont été identifiées pour leurs forts impacts sur les résultats ACV. Des propositions théoriques de changement de pratiques sont testées sur l’un des ITKv. Ces propositions améliorent les notes environnementales finales de +0,15 points à +0,77 points (/10) quand elles sont mises en œuvre séparément et +2,29 points (/10) en étant combinées. Un modèle explicatif de la qualité du raisin permet de vérifier que les nouvelles pratiques ne peuvent potentiellement pas altérer la qualité du raisin. La méthode d’évaluation conjointe CONTRA-QUALENVIC adaptée à la viticulture montre ici qu’elle peut être une aide à l’amélioration des ITKv.

L’objectif de cette étude était d’évaluer l’effet du croisement entre races bovines laitières sur les performances technico-économiques d’un atelier initialement en race pure Holstein, à partir d’un modèle individu-centré, mécaniste, stochastique et dynamique. Ce modèle a été conçu afin de prendre en compte les effets génétiques additifs et non-additifs sur les performances animales. Trois schémas de croisement ont été simulés sur 15 ans : Holstein x Montbéliarde, Holstein x Montbéliarde x Normande et Holstein x Montbéliarde x Rouge nordique. Les effets de ces stratégies ont été étudiés pour deux ateliers initiaux, différenciés par leur niveau de prévalence des troubles de la reproduction et de la santé (égal ou supérieur à la moyenne française), et pour des objectifs de maintien de l’effectif ou du volume de livraison. Après 5 années de simulation, et en comparaison au maintien en race Holstein, l’introduction du croisement a entrainé une baisse de la quantité annuelle moyenne de lait produite par vache. Cependant, cette introduction a induit une amélioration du TB, du TP, de la reproduction, de la santé de la mamelle et de la longévité. Dans les ateliers avec une prévalence des troubles moyenne, l’introduction du croisement a entrainé une augmentation moyenne de + 20 à + 32 €/vache/an et de + 7 à + 10 €/1000L/an de la marge brute annuelle moyennée sur 15 ans, selon des objectifs de maintien de l’effectif et de volume livré, respectivement. Dans les ateliers avec une prévalence des troubles élevée, cette augmentation a été d’environ + 75 à + 90 €/vache/an et de + 5 à + 7 €/1000L/an. Dans un contexte de prix d’achat des matières premières instable et de prix de vente du lait bas, le croisement entre races laitières apparait comme une voie pertinente pour améliorer les performances technico-économiques d’une partie des ateliers initialement en race pure Holstein

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; Field emergence is crucial in determining the yield and quality of French beans for the canning industry. The aim of this study was to analyze the variation in bean emergence results, particularly to determine the relative influence of seed characteristics and sowing conditions. During 2004 and 2005, at two sites in France (North: 50. 1 degrees N, 3 degrees E; West: 47.3 degrees N, 0.3 degrees W), field experiments were carried out in order to obtain information on bean emergence under a range of sowing conditions. Four seed lots of the cultivar Booster with differing germination and seedling growth parameters determined under laboratory conditions were sown. These field results were also used to compare observed results in the field with the simulations of a crop emergence model. Subsequently, the effects on crop emergence of a greater diversity of seed lots in the three main French cropping areas were simulated using the model. In the field experiment, germination rates were always high (80-100%). In contrast, final emergence rates varied from 56 to 90%, emergence lasting from 9 to 28 days. These differences were large between sowing situations but small between seed lots. Emergence was mainly delayed by low temperatures (

International audience; Archaeology offers evidence that growing plants together, with annual legumes as usually inevitable component, could be the most ancient cropping system in all primeval agricultural centres. With a ten millennia long tradition, intercropping annual legumes, usually with cereals and for diverse uses, has remained important all over the world until today. There is a phenomenon that brings together legume breeders and agronomists: both are aware that there are differences in the agronomic performance of the mixtures of annual legumes and other field crops if diverse annual legume cultivars are used. Wishing to understand this phenomenon properly and define its economic significance, we are establishing a firm interaction between breeders and agronomists, in order to design such annual legume ideotypes that would have the best agronomic performance when intercropped with diverse plants for either forage or grain or biomass or any other use. Our major hypotheses are that the ideotypes for intercropping are the genotypes being the most competitive in the same environment compartments or taking profit of the complementary compartments. However demanding, this is feasible: the preliminary schemes for forage and grain production, developed mostly at IFVCNS, produced encouraging results in field conditions. Joint efforts of annual legume breeders and agronomists should be beneficial for both scientific community and result in enhancing the legume cultivation and production in general.

International audience; In the context of protected designation of origin (PDO) wine production, wine organoleptic quality, and hence grape quality is a key target of vineyard management. LCA-based Improvement of Technical Management Routes (TMR) by choice of more environmentally friendly techniques needs to take into account this quality dimension in addition to the yield function usually considered in wine and grape LCAs. The aim of the paper is to present and discuss two proposals for including multi-criteria quality into eco-efficiency assessment of PDO grape production in order to support the choice, design and assessment of vineyard TMRs. We porpose the design of a combined quality index Q relating an observed multi-criteria quality to a atrgeted quality. A set of logical rules of inference (if...then...) was used considering several levels of correspondence of the product to the quality target. From this Index, a Quality Functional Unit (QFU =Q) and a Mass x Quality Functional Unit (MQFU=yield x Q) were defined. For application of Q to grape, a typology of grape quality targets with the different quality criteria and their levels for each grape type was established with expert-oenologists as a basis for Q. We tested the sensitivity of the two indexes to a change of quality target. We implemented the two FUs in LCA calculations on five al viticultural TMRs representing the Middle Loire Valley diversity for production of a same type of wine. The quality index Q was calculated for the five TMRs. The two FUs derived from Q were sensitive to a change of quality target. The LCA results of the five TMRs expressed per MQFU differed from results per QFU and were sensitive to a change of quality target. Results with QFU were close to those obtained with classical FUs (1 kg grapes and 1 ha vines, 1 year) due to minor differences in the value of Q. QFU appeared too restrictive while MQFU allowed accounting for the main function of the system : the production of a given quantity of quality grapes with a target of a given type of wine.

L’objectif de cette étude était d’analyser l’effet du croisement laitier sur la survie des veaux. Sur la période 2005-2012, 191109 veaux ont été sélectionnés. Les croisés de première génération (G1) ont été issus de mère Holstein (HO) et de père Montbéliard (MO) ou Normand (NO). En deuxième génération (G2), les veaux croisés ont été issus de mères HOxMO et HOxNO et de père HO, MO, NO, Rouge scandinave (RS) ou Brun des Alpes. La mortalité des veaux a été divisée en mortinatalité (mort à la naissance ou dans les premières 48 heures, après une durée de gestation supérieure à 260 jours) et en survie 2-30j (entre 2 et 30 jours pour les veaux femelles et entre 2 jours et leur sortie pour les veaux mâles). Les taux de mortinatalité ont varié entre les HO, les G1 et les G2 soit respectivement 9,56%, 11,10% et 6,49% chez les veaux de primipares et 5,15%, 5,91% et 4,30% chez les veaux de multipares. La survie 2-30j a été moins affectée par le croisement. Elle a varié en fonction du père, en faveur de MO chez les G1 et de HO et RS chez les G2. A l’inverse les veaux de mère HOxNO et père NO ont eu une survie diminuée. La survie des veaux G2 a été améliorée lorsque la mère était HOxMO. L’étude a montré qu’un effet du croisement s’observe principalement lorsque les mères sont croisées (hétérosis maternel) même si le père a une importance dans la survie du veau. Cependant certains résultats de l’étude peuvent être biaisés par manque d’effectif pour certains types de croisements

International audience

International audience; The aim of this paper is to gain an under standing into how agricultural policies have affected structural change in the French dairy sector. A nonstationary Markov model is estimated using a Generalized Cross Entropy approach. Results show that while the price of cow’s milk encourages farm growth, direct payments and quota restriction favor small farms. The price signal is a key factor of structural change. As a result, higher milk prices may accelerate the trend toward the further growth of dairy farms. Settlement policy and technical change seem not to slow this trend.; L’objectif de cet article est de comprendre comment les politiques agricoles ont affect´e le changement structurel dans le secteur laitier en France. Un modèle de Markov non stationnaire utilisant l’approche de Cross Entropie Généralise a été estimée. Les résultats montrent qu’alors que le prix du lait encourage l’augmentation de la taille des exploitations, les paiements directs et le quota laitier sont plutôt en faveur des petites exploitations. Le signal prix est un facteur clé du changement structurel. En conséquence, des prix du lait plus élevés pourraient accélérer la tendance vers des exploitations laitières de plus grande taille. Les aides `a l’installation et le changement technique ne semblent pas freiner cette tendance.

International audience

National audience

International audience

International audience