Improve Pasture or Feed Grain? Greenhouse Gas Emissions, Profitability, and Resource Use for Nelore Beef Cattle in Brazil’s Cerrado and Amazon Biomes

Abstract

Economic development, international food and feed demand, and government policies have converted Brazil’s natural ecosystems into agricultural land. The Integrated Farm System Model (IFSM) was evaluated using production, economic, and weather data collected on two cooperating farms in the Legal Amazon and Cerrado biomes in the Midwest state of Mato Grosso, Brazil. Three sustainable agricultural intensification strategies, namely grain supplementation, pasture re-seeding, and pasture fertilization were simulated in IFSM with double the beef cattle stocking density compared to extensive grazing. Livestock dry matter consumption simulated in IFSM was similar for pasture grazing estimates and actual feed consumed by beef cattle on the two collaborating farms. Grain supplementation best balanced beef production and profitability with lower carbon footprint compared to extensive grazing, followed by pasture fertilization and pasture re-seeding. However, pasture re-seeding and fertilization had greater use of water and energy and more nitrogen losses. Human edible livestock feed use was greatest for grain supplementation compared to other modeled systems. While grain supplementation appears more favorable economically and environmentally, greater use of human edible livestock feed may compete with future human food needs. Pasture intensification had greater human edible feed conversion efficiency, but its greater natural resource use may be challenging.

Biological and economic responses to increasing nitrogen rates in Mombaça guinea grass pastures

“…The recent work of Molossi et al . 40 , at some extent, corroborates our results. The authors, comparing farm-level profitability between extensive systems and systems with pasture N fertilization, found annual net returns of US$ 22.86 ha −1 and US$ 65.69 ha −1 , respectively, for a Cerrado representative farm, and of US$ 24.28 ha −1 and US$ 66.75 ha −1 , respectively, for an Amazon representative farm.…”

“…According to Molossi et al . 40 , the use of 100 kg ha −1 of N on Brachiaria pasture in the Brazilian Cerrado resulted in additional 82 kg carcass weight ha −1 , which could feed 2.35 more people per hectare, considering the global projection for annual per capita consumption of meat of 35.1 kg person −1 in 2028, than extensive systems (with no fertilization). In the same way, our results suggest that increasing N rates from 100 kg ha −1 to 200 or 300 kg ha −1 could potentially feed 5.3 or 2.7 more people, respectively, per hectare.…”

Closing the Gap: Sustainable Intensification Implications of Increased Corn Yields and Quality for Second-Crop (safrinha) in Mato Grosso, Brazil

“…SI of Brazil's beef systems involve transition from extensive grazing for almost 4 years to reducing time to slaughter using (1) semi-intensive feedlots (1.2 years) or (2) grain supplementation in pasture (1.7 to 2.4 years) [67]. Whole-farm modeling of pasture grain supplementation compared to extensive grazing demonstrated lower carbon footprint in southern Brazil [68] along with greater beef productivity and profits as well as lower greenhouse gas emissions and less energy and nitrogen use in Mato Grosso's Cerrado [69]. Feedlots were found in the Amazon and Cerrado biomes in Mato Grosso (MT), Pará, and Rondônia states to be associated with lower on-property deforestation [67].…”

“…For example with corn silage, increasing dry matter digestibility by 6.9% is associated with an increase in 0.20 kg/day live weight (0.17 kg/day carcass weight) gain in beef [71]. Assuming 126 day average finishing time in Brazil beef feedlots [72] and 430 kg live weight at slaughter [69,72], our 5.38% increase in corn silage digestibility from the low to high group (Table 4) suggests a marginal increase of 19.6 kg live weight (16.7 kg carcass weight) over 126 days of feedlot finishing. Assuming feeding rates (kg/head/day) estimated for semi-intensive feedlot corn silage (7.83) and corn grain (2.84) and pasture supplementation corn grain (1.42) used in Mato Grosso (MT) [73] and 126 feeding days for semi-intensive feedlots [72] and 237 feeding days for pasture supplementation [67], required feed for each finished head of beef can be estimated.…”

“…This is 88% of the total number of beef cattle slaughtered in Brazil in 2020 [74]. Grain supplementation (GS) in Cerrado pasture has been modeled to reduce carbon footprint by 3.01 kg CO 2 equivalent (eq)/kg body weight produced compared to extensive beef grazing [69]. Assuming Brazil can increase pasture-based grain supplementation for 26,143,647 of its cattle, this corresponds to a greenhouse gas emissions reduction of 33,837,722 metric tons of CO 2 eq.…”