Faculty of Technical Sciences

Phosphorus (P) is essential for life, but global commercial resources of mineral P are limited. P emissions from intensive pig and poultry farming raise environmental concerns. Approaches are needed to improve P bioavailabilityin feed and body P utilisation and retention as well as measures to regulate P release into the environment, taking into account economy, society, and ecology. The strategic objective of the ERA-NET funded project PEGaSus is to provideand evaluate solutions to sustainable agricultural systems with the focus on P management. To this end, the fate of P in feed, pigs and poultry, microbiota, manure, slaughterhouse wastes, and soil was tracked. Different feeding strategies and diets were tested which showed for example that supplementation of 250 FTU/kg diet (DM) phytase levels resulted in manure release with increased plant P use efficiency and decreased soil P availability, thus making the plant-soil system more P conservative. The endocrine and transcriptomic response of pigs and poultry to variable P supply offerperspectives for reduced mineral P input and P-efficient animals employing genetic and epigenetic mechanisms. A bio-economic farm optimisation model was developed to assess the farm level economic and environmental impactof alternative P management strategies. In view of the current P loading of soils and water bodies, the assessment has derived that current European regulations on manure spreading and fertiliser use should take much more account ofP surpluses and losses. The project contributes to providing novel sustainable P management approaches to reconcile the economic, social, and environmental sustainability of European pig and poultry production.