Feeding proteins to livestock: Global land use and foodvs.feed competition

Competition between direct consumption of plant production and the feeding of livestock is key to global food availability. This is because livestock consume edible commodities that could be available for (food insecure) populations but also because it diverts arable land from food production. The share of total plant production redirected towards feeding livestock is (roughly) known but estimations of land surfaces virtually occupied by livestock production are scarce. In this study, following up on the Agrimonde Terra** project, we estimate areas devoted to the feeding livestock. First, we estimate the protein composition of an averaged feed basket at the global scale in 2005 and detail the evolution of the protein-source feed component during the period 1961–2009. We focus on protein-rich crops such as oil crops and show its proportion in the global livestock diets has tripled since 1960, though only accounting for about one fourth of total proteins. Then, we estimate land virtually occupied by crop feed at the global scale using a set of straightforward hypotheses. Our estimates suggest that, although livestock and feed production has continuously increased and despite uncertainties in available data, competition for land between feed and food uses has decreased over the last two decades. The share of areas cultivated for feed requirements decreased from about 50% in the 1970s to 37% nowadays. This trend is attributable to the increase of crop yields and to a decrease of the share of cereals in livestock diets to the benefit of oilseeds by-products. However, estimating the share of total areas used for feed is complicated by the significant role played by by-products.