Aliments protéiques dans les systèmes mixtes intégrés polyculture-élevage en régions tropicales

In tropical regions, where rations are often deficient in protein, supplementation is crucial. Alternatives to the use of soybean meal are potentially available in integrated agroforestry systems and mixed crop-livestock systems, although the choice is wider for ruminants than for non-herbivorous monogastrics. The nutritional value of resources is not the only aspect for decision: the evaluation of feeding strategies, in a multi-criteria approach, has to consider their different productive and non-productive services. It should also take into account the possible competition between the use of resources by humans and animals. In the context of integrated mixed crop-livestock systems, the dual resources, which overall valorization satisfies the needs of human and animal, are strategic: seeds and vines of legumes, leaves and tubers of cassava or sweet potato, etc. Annual, perennial or tree legumes have important agronomic and environmental benefits in integrated systems by their ability to fix nitrogen. The role of recycling and the low influence on agricultural land of new sources of feed (aquatic plants, microorganisms, insects, earthworms) is also an asset for their development. The development of appropriate technologies to outweigh the limitations (antinutritional factors, feed preservation...) will fully value the potential of many protein resources.