Direct marketing of beef in organic suckler cattle farms: economic results and impact on breeding system management

In response to the bovine crises of 1996 and 2000, and also to the poorly structured organic beef market chain, direct marketing of beef to consumers by the farmer has developed. We studied the impact of this marketing system on economic performance and farming practices. The results show that direct marketing can generate added value, despite the extra costs. Farmers have made the necessary changes to their practices, and have adapted their herd management. Through strengthening the link between the farm and the outside world, direct marketing offers an alternative to the expansion of farms, making it possible to support a greater workforce with the same structure

FOOD SELF-SUFFICIENCY AND FARM ECONOMICS IN FRENCH ORGANIC SUCKLER CATTLE FARMS

The organic Charolais suckler farmers of the French Massif Central sell most of their animals on the conventional market. The high cost of the inputs, and in particular the concentrates, is an incentive for these suckler farmers to seek a high degree of food self-sufficiency on their farms. This self-sufficiency is reached through good management of grass and especially through cereal crops for animal feeding. The strong limitation of the inputs does not affect the numerical productivity or the health of the herd, but it entails lower meat productivity per animal and per hectare. However, the operational cost savings make it possible to maintain income per hectare at the same level as that of conventional farms

Environmental Good Production in the Optimum Activities Portfolio of a Risk Averse Farmer

An analytical framework is proposed for analysis of environmental good production by farmers in the case of price uncertainty. Environmental good production contracted by means of agri-environmental agreements is treated as a risk less option in the farmer's production activities portfolio. Efficient frontiers were generated using mathematical programming farm level models of suckler cow farms in Monts du Cantal, in France. It was demonstrated that for a DARA risk averse farmer: 1) the agreement payment level is not without impact on the farming intensity on parcels not subscribed under the corresponding argi-environmental programme, 2) a lump sum payment matters under uncertainty, 3) the overall impact of the lump sum payment on environmental good production depends on the type of jointness in production of agricultural and environmental goods, and on the level of uncertainty.uncertainty, portfolio optimisation, biodiversity, agricultural policy, mathematical programming, Agricultural and Food Policy, Resource /Energy Economics and Policy, Q12, Q18, Q28,

Environmental good production in the optimum activities portfolio of a risk averse-farmer

An analytical framework is proposed for analysis of environmental good production by farmers in the case of price uncertainty. Environmental good production contracted by means of agri-environmental agreements is treated as a riskless option in the farmer’s production activities portfolio. It is shown that agri-environmental agreements aiming at biodiversity competing with beef production are likely to increase management intensity on the non-enrolled land, and that the effect of the payments for these agreements on the number of hectares enrolled is ambiguous. It is also demonstrated that an increase in the output price variability and/or a decrease in the level of decoupled subsidies will induce an increase (decrease) in the area enrolled in agreements aiming at biodiversity competing with (complementary to) beef production. The obtained results are illustrated by means of efficient frontiers generated using mathematical programming farm level models of suckler cow farms in Monts du Cantal, in France.uncertainty, portfolio optimisation, biodiversity, agricultural policy, mathematical programming

An organic suckler cattle farming system in the Massif Central: analysis of technical and economic results.

in the Massif Central. An organic suckler cattle farm network was set up in order to establish technical and economic references. In 2004, 22 farms were monitored (13 of which had been monitored since 2001). All of these farms are located in economically-depressed areas. One hundred percent of the fodder area is under grassland. Annual crops (cereals and a cereal/pulse mix) take up 13% of the farm area and are used as livestock feed. The stocking rate (1 Livestock Unit/ha of fodder area) is 20% lower on organic farms than on conventional farms. Organic farms use 33% less concentrates per LU, and the meat production/LU is 16% lower than for conventional farms. The poorly structured organic beef market forces organic farmers to sell most of their animals (mainly store animals, since fattened animals represent only 43% of the animals sold) on the conventional market without getting premium prices. Since only fattened animals are sold on the organic market at a premium price, the average selling price (€/kg live-weight) of all the animals sold is only 12% higher for organically-bred than for conventionally-bred animals. However, because of lower operational costs (-35% for herd and fodder area costs), the bovine gross margin/LU is 3% higher for OF than for conventionally-bred animals. The lower stocking rate leads to a lower gross product per hectare of farm area. Since this result is balanced by a very low level of operational costs (no chemical inputs), the economic efficiency of the OF system is higher than that of the conventional system. The farm income per worker is the same in both systems. The search for feed self-sufficiency at the farm scale is a crucial element in farm economics, but it is only possible on mixed-crop livestock farms where cropping is possible with adapted crop rotation. The grassland farms, which are the least self-sufficient and have to purchase all the concentrates needed, must sell all their animals on the organic market to get the premium price that will then enable them to buy the inputs not produced on the farm

Impacts possibles de la réforme de la PAC de juin 2003 et de ses différentes options d'application sur des exploitations d'élevages bovins allaitants

La dernière réforme de la PAC poursuit celle de 1992, elle-même confirmée par l'Agenda 2000, dans le découplage des soutiens directs à la production. Afin de voir les adaptations des exploitations d'élevage bovin allaitant, des simulations de différentes options d'application de la réforme ont été faites pour les principaux cas d'exploitations, plus ou moins intensives, naisseurs ou naisseurs-engraisseurs de taurillons ou de boeufs, avec plus ou moins de cultures, situées dans les 3 régions charolaise, limousine et Pays de Loire. Les tendances qui se dégagent, après adaptations à prix stables, soutiens globalement maintenus et à superficie constante, sont la faible incidence sur le résultat économique, la réduction des cultures au profit des prairies et du cheptel, l'augmentation du nombre de vaches après diminution dans la situation de référence, le maintien de la finition des femelles avec les rapports de prix entre catégories de 1998, et l'engraissement des mâles plus difficile mais maintenu dans certaines options dans les systèmes naisseurs-engraisseurs étudiés.

Catherine Duprat, Usages et pratiques de la philanthropie. Pauvreté, action sociale et lien social, à Paris, au cours du premier XIXe siècle

Dans l'historiographie et dans les sciences humaines, le mot “philanthropie” a longtemps servi, selon divers points de vue, à désigner les pratiques d'assistance du premier XIXe siècle : dans une tradition marxiste, le terme est venu nommer l'action charitable (ou cruelle) d'une frange de la bourgeoisie sur le monde ouvrier, assurant par là la pérennité de sa domination ; dans les différentes histoires de la protection sociale, le mot a servi à désigner tantôt les origines de l'Etat-Providenc..

Immersing NURBS for CFD applications

International audienceWe present a new immersed method for solving conjugate heat transfer and fluid-solid interactions (FSI). It is based on the use of Non Uniform Rational B-Splines (NURBS) to compute the distance function ans thus representing the immersed solids inside the computational domain. Combined with anisotropic mesh adaptation and stabilized Finite Elements Method (FEM), it allows a novel, efficient and flexible approach to deal with turbulent flows and heat transfer inside large domains

Delay system identification applied to the longitudinal flight of an aircraft through a vertical gust

International audienceThis paper deals with modelling and identification of aircraft dynamic entering a vertical gust. The identification approach initiated in (Fliess 2003) falls under a prospect for identification from tests carried out in the Flight Analysis Laboratory of the DCSD of ONERA in Lille. The plane is considered into various elements which consist in the fuselage, the wing and the tail. The model incorporates delays linked to the aircraft passage through the atmospheric turbulence

Simulation des grands espaces et des temps longs

Fluid-Structure Interaction (FSI) describes a wide variety of industrial problems arising in mechanical engineering, civil engineering and biomechanics. In spite of the available computer performance and the actual maturity of computational fluid dynamics and computational structural dynamics, several key issues still prevent accurate FSI simulations.Two main approaches for the simulation of FSI problems are still gaining attention lately: partitioned and monolithic approaches. Results in the literature show that the partitioned approach is accurate and efficient but some instabilities may occur depending on the ratio of the densities and the complexity of the geometry. Monolithic methods are still of interest due to their capability to treat the interaction of the fluid and the structure using a unified formulation. In fact it makes the build up of a FSI problem easier as the mesh do not have to fit the geometry of the solids and the transfers are treated naturally.The software Thost has been created based on these analyzes. Thost is a 3D aerothermal numerical software. It has been developped for the numerical simulation of industrial processes like the heating in industrial furnaces as well as quenching. Its target is to model numericaly the thermal history of the industrial pieces in their environment without using any transfer coefficient. However the computational costs are still high and therefore the software is not fully efficient from an industrial point of view to simulate, analize and improve complex processes. All the work in this PhD thesis has been done to reduce the computational costs and optimize the accuracy of the simulations in Thost based on innovatives numerical methods such as dynamic anisotropic mesh adaptation, stabilized finite elements methods and immersing the objects directly from their Computer Aided Design files.L'interaction fluide structure est présente dans beaucoup de problèmes industriels, dans les domaines d'ingénierie mécanique, civile ou biomécanique. Même si les performances informatiques s'améliorent considérablement et que les méthodes en mécanique numérique gagnent en maturité, certaines difficultés ne permettent pas encore de réaliser des simulations numériques précises. Actuellement deux méthodes numériques gagnent en popularité pour la simulation numérique d'interactions fluide structure: la méthode de partitionnement et la méthode monolithique. Des résultats de la littérature montrent que la première est efficace et précise mais qu'elle peut rencontrer des problèmes d'instabilité si les ratios de densité sont élevés ou que les géométries sont complexes. Les méthodes d'immersion sont de plus en plus utilisées par la communauté scientifique. Différentes approches ont été développées, dont la Méthode d'Immersion de Volume. Cette méthode permet de faciliter la mise en place des calculs. Ainsi il n'est pas nécessaire de construire des maillages concordant avec la géométrie des objets, et le couplage entre les fluides et les solides se fait naturellement. C'est sur cette analyse qu'a été développé le logiciel Thost. Il permet de simuler des procédés industriels tels que le chauffage de pièces métalliques dans les fours industriels ou la trempe sans caractériser expérimentalement des coefficients de transfert. Le but d'un tel logiciel est de permettre une meilleure compréhension des procédés et ainsi de les optimiser. Cependant les coûts de calcul restant élevés, le but de la thèse est de les diminuer en s'appuyant sur des méthodes numériques innovantes tels que l'adaptation dynamique de maillage anisotrope, des méthodes éléments finis stabilisées ou l'immersion directe des objets à partir de la Conception Assistée par Ordinateur