LAUSR

In Brazil beef cattle production is one of the most important activities in the agricultural sector and has an important impact on environmental and resources consumption. In this study assessed greenhouses gases (GHG) impacts from on farms representative productive system and the possible improvements of the production chain. Primary data from animal production index and feeding were collected from 17 farms, which covers 300.000 animals and 220.000 hectares. Emissions of methane, nitrous oxide and carbon dioxide were made using intergovernmental panel on climate change (IPCC) guidelines for national inventories. The GHG inventory included emissions from animals, feeds and operations for animal operation from “cradle to farm gate”. Emissions of each farm were converted to carbon dioxide equivalent (CO2eq) and divided by carcass production. Regression analysis between carbon dioxide equivalent and productive index was run to identify possible hotspot of GHG emissions. A large variation between farms were observed. The GHG yield ranged from 8.63 kg to 50.88 CO2eq kg carcass-1. The productive index age of slaughtering (P < 0.0001), average daily gain (P < 0.0001) and productivity (P = 0.058) per area were positive correlated to GHG yield. While no correlation was found with stocking rate (P = 0.21). Improvements of the production chain could be realized by accurate animal management strategies that reduce the age of slaughtering (feeding and genetic improvements) and gain individual or per area using strategic animal supplementation and pasture management, in order to obtains reduction of GHG emissions of beef cattle.