This study describes the fecal microbiota from piglets reared in different living environments during the weaning transition, and presents the characteristics of microbiota associated with good growth of piglets after weaning. Fecal samples were collected pre- (d26) and post-weaning (d35) from 288 male piglets in 16 conventional indoor commercial farms located in the West of France. The changes one week after weaning on the most abundant microbial families was roughly the same in all farms: alpha diversity increased, the relative abundance of Bacteroidaceae (-61%), Christensenellaceae (-35%), Enterobacteriaceae (-42%), and Clostridiaceae (-32%) decreased, while the relative abundance of Prevotellaceae (+143%) and Lachnospiraceae (+21%) increased. Among all the collected samples, four enterotypes that were ubiquitous in all farms were identified. They could be discriminated by their respective relative abundances of Prevotella, Faecalibacterium, Roseburia, and Lachnospira, and likely corresponded to a gradual maturational shift from pre- to post-weaning microbiota. The rearing environment influenced the frequency of enterotypes, as well as the relative abundance of 6 families at d26 (including Christensenellaceae and Lactobacillaceae), and of 21 families at d35. In all farms, piglets showing the highest relative growth rate during the first three weeks after weaning, which were characterized as more robust, had a higher relative abundance of Bacteroidetes, a lower relative abundance of Proteobacteria, and showed a greater increase in Prevotella, Coprococcus, and Lachnospira in the post-weaning period. This study revealed the presence of ubiquitous enterotypes among the farms of this study, reflecting maturational stages of microbiota from a young suckling to an older cereal-eating profile. Despite significant variation in the microbial profile between farms, piglets whose growth after weaning was less disrupted were, those who had reached the more mature phenotype characterized by Prevotella the fastest.

No abstract

Grasslands offer many environmental and economic advantages that put them at the heart of 17 future sustainable ruminant production systems. This study aimed to quantify and map the dry 18 matter yield (DMY) and nitrogen yield (NY) of French grasslands resulting from cutting and 19 grazing practices, based on the existing diversity of grassland vegetation, management, soil 20 and climate conditions, using a research version of the STICS crop model called PâturSTICS. 21 This model simulates daily dry matter (DM), nitrogen (N) and water fluxes involved in the 22 functioning of grasslands and crops in response to management and environmental conditions. 23 It was improved to represent deposition of animal waste on grassland soils during grazing and 24 to simulate DM production and N content of grasses and legumes more accurately. 25Simulations were performed for locations across France on a high-resolution grid composed 26 of pedoclimatic units (PCU) obtained by combining the spatial resolutions of climate and soil. 27The main grassland types and associated management types were determined for each PCU 28 and then simulated over 30 years . Using the simulated values, predictive 29 metamodels of annual grassland DMY and NY were developed from easily accessible 30 explanatory variables using a random forest approach. Annual model predictions were 31 aggregated and averaged at the PCU scale, then compared to regional observations. Predicted 32 DMY agreed with available observations, except in semi-mountainous and mountainous 33 regions, where PâturSTICS tended to overpredict DMY, probably because it ignores effects of 34 *Manuscript Click here to view linked References Version postprint