Intégrer les changements d’échelle pour améliorer l’efficience des animaux et réduire les rejets

Livestock production is facing the challenge to adapt to the problem of competition for resources (especially food resources) and to reduce its environmental impact. Improving the efficiency of converting food resources into animal-derived products is an important way to address both issues simultaneously. This review paper addresses the notion of efficiency by placing it in a broader context of the performance triangle composed of relevance, efficiency, and effectiveness. We will show that feed efficiency issues have to be considered at different levels of organization. For the meat and dairy production sectors, we address research that has been carried out to improve feed efficiency through selection of animals that are better capable to transform feed resources into animal-derived products and through feeding techniques in which the nutrient supply is better adjusted to the animal’s requirement. We also discuss progress that has been made to reduce the environmental impact of livestock production. Considering feed efficiency and emission reduction at the animal level is important and offers a considerable prospect for progress. However, it does not guarantee that efficiency is improved and that environmental impact is reduced at higher levels of organization. It is important to ensure that the proposed livestock management strategies are effective and that they achieve the desired objectives using appropriate indicators. This going-back-and-forth between different levels of organization to improve the overall performance of livestock production is a new challenge for research.