Grazing supplementation and crop diversification benefits for southern Brazil beef: A case study

Profitability and environmental benefits of beef cattle raised on natural pasture or combined with soybean in tropical biomes need to be better evaluated. The objective of this research was to simulate and evaluate three common pastured beef grazing systems in southern Brazil, estimating profitability and the environmental impacts of carbon footprint (CF) measured as kg of CO2 equivalent per kg of body weight produced (BWP), water footprint (kg of water used/kg of BWP) and energy footprint (MJ of energy used/kg of BWP) using the Integrated Farm System Model version 4.2. Simulations were run for Angus beef cattle raised on natural pasture (NP), natural pasture with low levels of grain supplementation (NPS), and NPS combined with soybean production (NPSC). Net animal weight produced (kg/ha/year) increased 7.9% for NPS and NPSC when compared with the NP system. Natural pasture production costs per hectare were lower (US$ 114) than that of NPS (US$ 126) and NPSC (US$ 233), while NP had a net return per hectare only 2% greater than NPS. Even though the gross income from animal sales was 5% higher in NPS than NP, the elevated cost of purchased feeds reduced net return per hectare. While costs were higher for NPSC, diversifying with soybean production, a high value commodity for cash sale, was profitable resulting in 44% and 47% greater net return per hectare than NP and NPS, respectively. Natural pasture with low supplementation (NPS) decreased CF by 2% when compared with NP due to faster weight gain from supplementation despite higher emissions from feed production. Furthermore, CF was also 6% lower for natural pasture combined with soybeans (NPSC) compared with NPS. However, the energy and water footprints and erosion increased with the greater use of both purchased feed and inputs required for feed and cash crop production. It can be challenging to increase beef cattle productivity and diversification to lower GHG emissions while minimizing water and energy use and soil erosion.