Regional-scale trade-offs among beef production, emissions and land use impacts: A cattle diet composition perspective

CONTEXT

Although playing a role in global food security, beef production systems cause concerns due to pressure on land for feed production and greenhouse gas emissions.

OBJECTIVE

We aimed at quantifying the trade-offs associated with different beef cattle diet compositions, considering beef meat production, greenhouse gas emissions, and land use impacts. In addition, we evaluated the influence of dry periods and grazing improvement for trade-off mitigation.

METHODS

We developed a model linking beef cattle diet composition to land use impact indicators (feed import requirements and feed-food competition indicators), beef production (proxied by total weight gain [WG]), and animal emissions in a year. We applied the model to the grassland-based beef cattle region of Bourbonnais, France, with a three-step analysis: (i) we explored the model outputs over a joint range of cereal and grass intake; (ii) we investigated the sensitivity of each feed type intake on the outputs; (iii) we simulated scenarios representing situations affecting cattle diet: dry seasons (−20% average crop and grass yield, grazing time, cattle growth rate and less cattle grass intake compensated by an equivalent increase of other feed types), grazing improvement (increasing grass yield by 20% and its digestibility and gross energy content by 5%) and mixed (combining the previous scenarios).

RESULTS AND CONCLUSIONS

Analysis (i) showed that more digestible diets conciliate production with emission reduction; however, they also cause undesired feed imports and feed-food competition. Analysis (ii) showed that, although present in the diet in relatively small quantities, oil protein crops as feed have high impact on model variables and outputs. In analysis (iii), compared to baseline, dry seasons decreases slightly in WG and emissions but increases feed-food competition (human-edible feed +149 g/kg WG) with extra feed importations; Grazing improvement increases WG (+6.02%) and decreases emissions (−3.03%), human-edible feed per WG (−37 g/kg WG) and food-competing land per WG (−5.7$\times$10⁻⁵ ha/kg WG) with no additional impact on feed imports; mixed scenario, increases total WG (+1.22%); decreases emissions (−3.25%) with less feed-food competition and less importation than baseline scenario.

SIGNIFICANCE

Beef cattle diet composition, linked to land-use based management practices, is an effective tool to handle the trade-offs at the regional scale. Improving pasture quality alleviates the trade-offs by increasing production, reducing emission, feed-food competition and feed imports. Improving resilience of grasslands to droughts alleviates the negative impacts of dietary changes during dry periods.