Effect of feeding Leucaena with or without polyethylene glycol on rumen methane production and degradability using in vitro gas production technique - Guerrini, Vitor Bonatto; Soltan, Yosra Ahmed; Abdalla, Adibe Luiz; Louvandini, Helder (Simpósio Internacional de Iniciação Científica da Universidade de São Paulo - SIICUSP, 2011)