A Global Meta-Analysis About Organic Vs Conventional Livestock Production

Livestock plays a key role in organic farming system to close nutrient cycles. Nevertheless, differences between organic and conventional livestock production have received little attention in the literature. Here, we provide a first quantification of differences in animal production and feed use efficiency between organic and conventional farming at the global scale using a meta-analytic approach. We focused on dairy cattle, pigs, poultry layers and broilers as the most represented species. We found (i) a 14% lower productivity for organic dairy cattle, (ii) an 11% and 89% lower feed use efficiency respectively for organic dairy cattle and poultry broilers, (iii) and a lower competition between feed and food use for organic cattle dairy. These results are key to accurately model global organic systems and to assess their potential contribution to global food security