Effects of livestock species diversity on the economic performance of commercial farms compared to specialized ruminant farms

Animal diversity in a farm is supposed to bring economic and environmental benefits, through the possible interactions between the different farm livestock units (or components)s. This analysis compared the performance of mixed livestock systems with specialized livestock systems. The results show an increased economic and social performance only for mixed ruminant and monogastric farms. In addition, their environmental performance for nitrogen balance is degraded compared to mixed livestock systems with only ruminants and specialized ruminant systems

Future Needs for Tribo-Corrosion Research and Testing

Tribo-corrosion is an emerging interdisciplinary subject that spans from basic research on the behavior of surfaces in mechanical contact in chemically active surroundings to the test methods needed to quantify its effects, and from the selection of materials for bio-implants to the minimization of surface degradation and wastage in advanced energy conversion systems. Such a diverse field brings with it many challenges in understanding, testing, standardization, and application to engineering practice. This paper summarizes a panel discussion and participant survey held at the Third International Symposium on Tribo-Corrosion in Atlanta, Georgia, USA, in April 2012. It reflects a sense of agreement on many of the key scientific challenges in the field and the fact that tribo-corrosion is still in its infancy in terms of broad industry recognition, education, and the ability of those who conduct tribo-corrosion research to connect their laboratory results and theories to applications. Some sub-fields, notably the bio-tribo-corrosion of medical implants, have witnessed active international research efforts, but the engineering community in many other important areas of technology may not yet be aware of the field despite numerous tribo-corrosion problems that may exist within their purview

Rigorous derivation of a nonlinear diffusion equation as fast-reaction limit of a continuous coagulation-fragmentation model with diffusion

Weak solutions of the spatially inhomogeneous (diffusive) Aizenmann-Bak model of coagulation-breakup within a bounded domain with homogeneous Neumann boundary conditions are shown to converge, in the fast reaction limit, towards local equilibria determined by their mass. Moreover, this mass is the solution of a nonlinear diffusion equation whose nonlinearity depends on the (size-dependent) diffusion coefficient. Initial data are assumed to have integrable zero order moment and square integrable first order moment in size, and finite entropy. In contrast to our previous result [CDF2], we are able to show the convergence without assuming uniform bounds from above and below on the number density of clusters

Savoir caractériser les complémentarités entre cultures et élevage pour accompagner la reconception des systèmes de polyculture - élevage dans leurs transitions agroécologiques

International audienceIntegrated Corp-Livestock farming systems (ICLS) should be able to maximize the implementation of agro-ecologic practices. Crops feed livestock and manure fertilize crops, which creates a virtuous circle. However, integrated crop-livestock farming systems cover a diversity of agricultural systems without consensus on how to charaterize them,. As each form of ICLS has not the same aims, they also do not have the same economic and environmental performances. To archieve obtaining situations with the expected virtuous theoretical characteristics, these systems will have to implement different changes. This is wath we describe through the experience of four experimental farms and several communications made during the symposium : "Les polycultures-élevages : valoriser leurs atouts pour la transition agroécologique" in Dijon in October 2017, as well as results from analyzes and presentations of methods and tools developed for these systems.Les systèmes de polyculture-élevage ont théoriquement les moyens de maximiser la mise en oeuvre de pratiques agroécologiques : les cultures alimentent le troupeau dont les effluents fertilisent les terres selon un cercle vertueux. Cependant, le terme « polyculture-élevage » (PCE) masque une diversité de systèmes sans l’existence d’un consensus sur la façon de la caractériser. Or, chaque forme de PCE ne va pas viser les mêmes objectifs, ni avoir les mêmes performances environnementales et économiques. Pour atteindre des situations où les caractéristiques théoriques vertueuses attendues sont obtenues, ces systèmes auront des trajectoires différentes. C’est ce que nous montrons à travers l’expérience de 4 exploitations expérimentales et de présentations faites lors du colloque « Les polycultures-élevages: valoriser leurs atouts pour la transition agroécologique » à Dijon en Octobre 2017, ainsi que de résultats d’analyses et de présentations de méthodes et outils de conseil développés pour ces systèmes

Multi-species livestock farming

This CORE Organic Practice Abstract gives practical recommendations for multi-species livestock farming, which has the potential to improve the three dimensions of sustainability – economic viability for farmers, environmental soundness, and social acceptability – by being respectful of animals and humans, as long as locally relevant farming practices are implemented, especially an appropriate stocking rate during grazing

Climate impacts due to albedo change of grassland through grazing and mowing practices in various pedoclimatic situations

International audienc

L’Albédo : le pouvoir réfléchissant du rayonnement

National audienc