13 research outputs found

    Ecofog - Gagner en compétitivité et réduire les impacts environnementaux de la filiÚre foie gras

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    On a worldwide scale, France is the leading producer of foie gras. To maintain this leadership, the sector must remain competitive and control its production costs while meeting specific societal and environmental expectations such as preservation of product quality, respect for animal welfare or limited use of natural resources. The aim of the project was to develop innovative production systems that would limit the impacts of feed and its surrounding practices on the competitiveness of the sector and the environment. An experimental approach was associated with a multi-criteria sustainability assessment (farm level), complemented by an analysis of production cost (farm level) and environmental impacts (product level). Two domains were studied: one related to feed, and the other related to ambient conditions during breeding and force-feeding. Several issues have been identified to progress. Reducing the amount of food distributed (-10%) appears as a possible solution to reduce feeding costs during rearing. The use of sorghum is also of interest but its use should be limited to the rearing phase. Lastly, semi-open air system, compared to open-air system, helps to improve IC (Consumption Index) and reduces animal heterogeneity and mortality. This project also provided original results related to the understanding of mechanisms involved in body temperature regulation of ducks on the one hand and on the other hand to LCA results of different innovations. Lastly, it contributed to the creation of two tools: one to drill ventilation ducts and another to calculate production costs. The results were disseminated to the professionals throughout the project in order to make all data available.À l’échelle mondiale, la France est le premier producteur de foie gras. Afin de conserver ce leadership, la filiĂšre doit rester compĂ©titive et maĂźtriser ses coĂ»ts de production tout en rĂ©pondant Ă  des attentes sociĂ©tales et environnementales spĂ©cifiques telles que la prĂ©servation de la qualitĂ© des produits, le respect du bien-ĂȘtre animal ou la gestion Ă©conome des ressources. Le projet ECOFOG avait pour objectif de dĂ©velopper des systĂšmes de production innovants, permettant de limiter l’impact de l’alimentation des canards et des pratiques qui l’entourent pour gagner en compĂ©titivitĂ© de la filiĂšre et diminuer l’impact environnemental de la filiĂšre. La dĂ©marche expĂ©rimentale a Ă©tĂ© associĂ©e Ă  une dĂ©marche d’évaluation multicritĂšre de la durabilitĂ© Ă  l’échelle de l’atelier, complĂ©tĂ©e par une analyse des coĂ»ts de production Ă  l’échelle de l’atelier et des impacts environnementaux Ă  l’échelle du produit. Deux axes d’étude ont en particulier Ă©tĂ© dĂ©veloppĂ©s : l’un autour de l’aliment, et l’autre autour des conditions d’ambiance en Ă©levage et en gavage.Plusieurs pistes ont Ă©tĂ© identifiĂ©es pour progresser. La rĂ©duction de la quantitĂ© d’aliment distribuĂ© (-10%) est une solution possible pour rĂ©duire les coĂ»ts d'alimentation. L’utilisation de sorgho prĂ©sente par ailleurs un intĂ©rĂȘt environnemental mais son utilisation devrait ĂȘtre limitĂ©e Ă  la phase d’élevage. En termes de bĂątiments enfin, le systĂšme semi plein-air, comparĂ© au systĂšme plein-air, contribue Ă  amĂ©liorer l’IC (Indice de Consommation) et rĂ©duit les Ă©carts de poids entre les animaux et la mortalitĂ©. Ce projet a permis d’obtenir des rĂ©sultats originaux sur les mĂ©canismes impliquĂ©s dans la rĂ©gulation de la tempĂ©rature corporelle des canards. Il a aussi permis d’évaluer les impacts environnementaux de la production de foie gras, et d’analyser les consĂ©quences des diffĂ©rents systĂšmes de production innovants sur les performances, les coĂ»ts et la durabilitĂ© de la production. Il a enfin contribuĂ© Ă  la crĂ©ation de deux outils utiles pour la filiĂšre : un outil d’aide au perçage des gaines de ventilation en atelier de gavage et un outil de calcul du coĂ»t de production. Ces rĂ©sultats ont Ă©tĂ© largement diffusĂ©s vers les professionnels afin de rendre l’ensemble de ces donnĂ©es disponibles

    Quaternary atoll development : new insights from the two-dimensional stratigraphic forward modelling of Mururoa island (central Pacific ocean).

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    International audienceKnowledge about the Quaternary evolution of mid-ocean atolls comes mainly from drilling and field observations carried out on a number of Pacific carbonate islands. However, little is known about the early to mid Pleistocene atoll development history, especially at margin and foreslope settings. Using previous field and subsurface data from Mururoa Atoll and a process-based modelling software (DIONISOS), a two-dimensional forward stratigraphic model of atoll development is proposed for the past 1·8 million years (Myr). Observational data from vertical to inclined coring, seismic and bathymetric surveys indicate that, from approximately 0·45 to 0·40 million years before present (Ma), carbonate deposition at Mururoa Atoll resulted in a series of mostly prograding reef units. The model is first constrained at the base by the shape and topography of the pre-Quaternary basement. A number of sensitivity tests were performed to define the respective influence of variant parameters. The best-fit development scenario that accounts for the overall geometry and stratigraphic architecture of the Quaternary sediment packages is obtained by using the sea-level curve by Miller et al. (2005), uniform subsidence rate of 105 m Myr−1, and carbonate production rates gradually increasing from 0·50 to 8 mm yr−1 between 1·80 Ma and the present. Additional controlling parameters include subaerial erosion (at a constant rate of 0·25 m/kyr), wave-energy and sediment-transport processes. The stratigraphic forward model predicts a succession of three distinct types of carbonate systems that have developed since the earliest Pleistocene: toe of slope systems from 1·80 Ma to about 0·80 Ma, open-platform systems from 0·80 Ma to 0·50 Ma, and framework-reef systems from about 0·50 Ma to the present. The development of these different systems is most likely to be controlled by climate and changes in sea-level cycles. During the low-amplitude 41 kyr cycle periods of the earliest Pleistocene, ambient conditions were not conducive to framework-reef growth; shallow-water carbonate sedimentation was dominantly gravity-driven, operating along the platform foreslopes only. During the Mid-Pleistocene Climate Transition, narrow, open-platform units have developed at the upper parts of the pre-Quaternary basement flanks. With the onset of the high-amplitude 100 kyr sea-level modes and climate restoration, reef frameworks started to be generated. These models from Mururoa agree with a number of previous studies suggesting that most of the true framework reefs were not initiated prior to 0·50 Ma. Mururoa Atoll is demonstrated to be a robust analogue for providing more realistic interpretations of the development history of Pacific atolls. Further modelling with three-dimensional DIONISOS could generate better predictions by taking into account hydrodynamic and transport parameters more accurately
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