Animal nutrition is a key factor in guaranteeing the sustainability of livestock farming, especially in the intensive production of monogastrics. The environmental impact of this sector is mainly related to the production of feedstuffs and manure management. Feed ingredients determine the environmental footprint of feeds. Under our conditions, soy replacement with local protein sources and an increase in the use of by‑products could, initially, improve the sustainability of feeds. However, in order to assess the real environmental benefits of these strategies, it is necessary to have accurate information about the origin and the effects on nutrient digestibility and productivity of these ingredients. On the other hand, there exists a direct relationship between feeding, nutrient excretion and gas emission from excreta in pigs and poultry. Reducing protein in feed reduces ammonia emission from excreta. However, for other nutrients like fiber and fat, this relationship is more complex. The implementation of strategies based on precision nutrition, the use of technology (pre‑treatments and enzymes) to increase the digestibility of feedstuffs or the control of gut health is essential to increase the efficiency in the use of resources and reduce the environmental impact of livestock. This work describes the state of the art in the formulation of sustainable feeds and the improvement in the use of nutrients.

Cerisuelo A, Calvet S (2020). La alimentación en producción intensiva de animales monogástricos: Un elemento clave para reducir su impacto ambiental. ITEA‑Información Técnica Económica Agraria 116(5): 483-506. https://doi.org/10.12706/itea.2020.039