Matching type of livestock to desired biodiversity outcomes in pastures - a review

From a review of the literature, we conclude that the main mechanism by which grazing livestock affect biodiversity in pastures is the creation and maintenance of sward structural heterogeneity, particularly as a result of dietary choice. We identify lack of understanding of the currencies used by animals in their foraging decisions and the spatial scale of these decisions as major constraints to better management. We conclude that there are important differences between domestic grazing animal species in their impact on grazed communities and that these can be related to differences in dental and digestive anatomy, but also, and probably more importantly, to differences in body size. Differences between breeds within species appear to be relatively minor and again largely related to body size. We conclude that there is an urgent need to understand the genetic basis of these differences and also to separate true breed effects from effects of rearing environment. We also review the economic implications of using different animal types and conclude that there is a need for more research integrating these aspects with biodiversity outcomes. (C) 2003 Elsevier Ltd. All rights reserved.