Introduction

Green-leaves plants, through the process of photosynthesis, lie at the base of the food chain of livestock systems. As a result, the vegetation has a huge capacity for soil generation and carbon fixation. However, little attention has been devoted to grazing practices during the last decades in many livestock systems as a result of intensification all around the world, whereas it has become more and more evident the problem of sustainability of conventional livestock systems. Independently of the causes, some of the consequences are directly related to environmental impacts such as soil quality degradation, erosion, and finally, desertification.