Modeling enteric methane emission from beef cattle in Brazil: a proposed equation performed by principal component analysis and mixed modeling multiple regression.

Brazil has the largest commercial beef cattle herd in the world but does not have its own model to predict methane (CH4 ) emission. The aim of this study was to create the first empirical enteric CH4 emission equation from variables that describe the animal diet using a meta-analytical data from Brazilian scientific publications (n = 50, published from 2003 to 2012).