Environmental assessment of ‘Boi 7-7-7’ beef cattle production protocol: greenhouse emissions

Beef cattle in Brazil are mainly raised in intensive systems of production. This implies in large greenhouse gas emissions (GHG). The boi 7-7-7 is a conceit which consists that the animal gain 7 @ (arrobas, one arroba is 15 kg carcass) in each phase, cow-calf, rearing and finishing in 24 months. To achieve this goal is required a good genetic and corporal score of the cow, pastureland well managed and supplementation in the rearing phase and a diet rich in grain in the finishing phase. Economic benefits of this protocol were showed and may be resulting in environmental gains. We aimed to assess the environmental impact of the boi 7-7-7 compared to the conventional beef cattle production system (CPS). To calculate the carbon footprint the model described by Cardoso et al. (2016) was used. Animal performance inputs like animals weights, feed characteristics, weight gain, etc. were obtained from Roth (2012), Moretti et al. (2014) and Vellini et al. (2014) that subsidize the concept of boi 7-7-7. The scenery 2 of Cardoso et al. (2016) was used as the conventional beef cattle production system because they calculated carbon footprint (CF) and land use based in the "average Brazilian system of production". The model simulates emissions from all important sources of methane (CH₄), nitrous oxide (N₂O), and carbon dioxide (CO₂) emitted in a beef cattle production system of whole cycle. The emissions source include enteric fermentation, manure, cropland used in feed production, fuel combustion, electricity, machinery and fertilizer usage. The total CH₄, N₂O and CO₂ emissions from boi 7-7-7 production scenery increased 11.67%, 354% and 678%, respectively, compared to that CPS. The carcass production was 42.07% higher than the CPS. The calculated CF's were 31.8 and 37.9 kg CO₂e kg^-1 carcass for boi 7-7-7 and CPS, respectively. One head emitted from the birth to slaughter 12166 and 14491 kg CO₂e, respectively, for boi 7-7-7 and conventional system. Due the increase in the productivity a reduction of 17% in the GHG emissions intensity was observed when adopted the boi 7-7-7 protocol. Implement the Boi 7-7-7 beef cattle production protocol is an opportunity to mitigate environmental pollution once the gain in productivity surpassed the increase in the GHG emissions.