Mixed crop-livestock farming systems: a sustainable way to produce beef? Commercial farms results, questions and perspectives.

Mixed crop-livestock (MC-L) farming has gained broad consensus as an economically and environmentally sustainable farming system. Working on a Charolais-area suckler cattle farms network, we subdivided the 66 farms of a constant sample, for 2 years (2010 and 2011), into four groups: (i) 'specialized conventional livestock farms' (100% grassland-based farms (GF), n=7); (ii) 'integrated conventional crop-livestock farms' (specialized farms that only market animal products but that grow cereal crops on-farm for animal feed, n=31); (iii) 'mixed conventional crop-livestock farms' (farms that sell beef and cereal crops to market, n=21); and (iv) organic farms (n=7). We analyse the differences in structure and in drivers of technical, economic and environmental performances. The figures for all the farms over 2 years (2010 and 2011) were pooled into a single sample for each group. The farms that sell crops alongside beef miss out on potential economies of scale. These farms are bigger than specialized beef farms (with or without on-farm feed crops) and all types of farms show comparable economic performances. The big MC-L farms make heavier and consequently less efficient use of inputs. This use of less efficient inputs also weakens their environmental performances. This subpopulation of suckler cattle farms appears unable to translate a MC-L strategy into economies of scope. Organic farms most efficiently exploit the diversity of herd feed resources, thus positioning organic agriculture as a prototype MC-L system meeting the core principles of agroecology.