Assessing the sustainability of a combined extensive/intensive beef production system: the case of French suckler cow-calf farms integrated with Italian beef fattening herds

This study aimed to analyse the sustainability of the beef system based on the integration between pasture-based suckler cow-calf farms in France (Massif Central) and cereal-based fattening farms of northern Italy. Two indicators were considered: carbon footprint (kg CO2-eq/kg body weight, BW, sold), and the human-edible feed conversion ratio computed as the ratio between the energy content in human-edible feedstuffs and the energy content of human-edible animal products (HeFCR). The reference unit was the batch (i.e. a group of stock calves homogenous for origin, finishing period and fattening farm). We considered 73 Charolais young bulls batches (4882 heads), born in France (Massif Central), sold to northern Italy beef herds at 405±13 kg BW after a 1.16±0.13 kg/d weight gain and slaughtered at 729±23 kg BW, after a 1.52±0.09 kg/d weight gain during fattening. Mean carbon footprint of overall beef production system averaged 13.0±0.6 CO2-eq/ kg BW, and the French suckler cow-calf phase accounted for 65% of global emissions. Conversely, the French suckler cow-calf phase was more efficient than the Italian beef finishing phase in terms of food supply for the human consumption, as the HeFCR averaged 2.9±0.4 and 4.6±0.8 MJ/MJ in the French and Italian phases, respectively. Therefore, our results suggest that the evaluation of global sustainability of mountain livestock systems would require the use of different indicators and approaches.