Benefits of adaptative multi-paddock grazing – implementation in French livestock production systems

International audienceThe beef industry and livestock production systems are at the centre of debates questioning GHG emissions and the environment more generally. To improve sustainability and to highlight the contributions of the beef sector has thus become a national and international goal of involved actors. Along with other solutions, grazing management techniques, such as adaptive multi-paddock grazing (AMP), have been suggested to provide services related to production, carbon sequestration, biodiversity, landscape, farmers’ workloads and many other aspects at the farm level. Though, a number of studies have compared different grazing systems around the world (e.g. rotational vs continuous), only few have performed integral multicriteria analyses. Hence, there is urgent need to assess advantages and disadvantages of climate-smart grazing practices based on common and comparable indicators (e.g. ecosystem services). In the present study, we will compare three different grazing systems including AMP, implemented in 27 commercial farms on three pedo-climatic regions. For each grazing system we examine grassland production (quantity and quality), carbon sequestration, biodiversity, and technical-economic results. This work will provide relevant information for grazing management aiming to achieve desired environmental and economic goals, and will put forward interesting grazing systems to meet multiple challenges (services)

Evaluation of perceptions of the functions of local ruminants breeds in Mayotte

Session 56 - Poster 10International audienceIn Mayotte, local populations of ruminants are well adapted to the difficult breeding conditions of the island. The importation of animals and artificial insemination with European breeds, has led to a policy of crossbreeding and a decrease of the size of the local breeds herds. The work carried out by CIRAD, INRAE and the Chamber of Agriculture enabled the characterization of local bovine, ovine and caprine breeds. These three populations are a reservoir of adaptive genes. The conservation of domestic breeds is often considered from a genetic and zootechnical perspective. However, the choice of breeds follows along socio-economic dimensions. Two studies questioned the perception that breeders have of local breeds. The first study aimed at understanding the factors that influence the preservation or abandon of the Mahoran zebu breed. Sixty farmers were surveyed through semi-structured interviews. The data collected made it possible to describe the diversity of cattle farms in five types: (T1) small traditional farms; (T2) small precarious farms; (T3) farms specialized in dairy production; (T4) intermediate farms between tradition and intensification; (T5) farms in transition. The zebu is used for its ease of breeding and its resistance, in addition to its heritage and cultural value (T1, T2). It is of economic interest for crossbreeding (T3, T4) and ¾ of the breeders note the superior quality of its meat. The second study which is based on comprehensive interviews carried out on 19 farms on the island, explore the link between the functions assigned by the farmer to his small ruminant herd and the choice of its genetic composition. Both of these studies help to define the design of the conservation programs of the ruminant breeds in Mayotte, based on farmers perspectives

The Arabidopsis SAC9 Enzyme defines a cortical population of early endosomes and restricts PI(4,5)P 2 to the Plasma Membrane

Membranes lipids, and especially phosphoinositides, are differentially enriched within the eukaryotic endomembrane system. This generates a landmark code by modulating the properties of each membrane. Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P 2 ] specifically accumulates at the plasma membrane in yeast, animal and plant cells, where it regulates a wide range of cellular processes including endocytosis. However, the functional consequences of mispatterning PI(4,5)P 2 in plants are unknown. Here, we functionally characterized the phosphoinositide phosphatase SUPPRESSOR OF ACTIN9 ( SAC9 ) in Arabidopsis thaliana (Arabidopsis). We found that SAC9 depletion led to the ectopic localization of PI(4,5)P 2 on cortical intracellular compartments, which depends on PI4P and PI(4,5)P 2 production at the plasma membrane. SAC9 localizes to a subpopulation of trans -Golgi Network/early endosomes that are spatially restricted to a region close to the cell cortex and that are coated with clathrin. Furthermore, it interacts and colocalizes with the endocytic component Src Homology 3 Domain Protein 2 (SH3P2). In the absence of SAC9, SH3P2 localization is altered and the clathrin mediated endocytosis rate is significantly reduced. Thus, SAC9 is required to maintain efficient endocytic uptake, highlighting the importance of restricting the PI(4,5)P 2 pool at the plasma membrane for the proper regulation of endocytosis in plants. One-sentence summary SAC9 prevents the accumulation of PI(4,5)P 2 along the endocytic pathway in plants and thereby contributes to the clathrin mediated endocytosis process at the plasma membrane via its interaction with SH3P