In recent years the concern with methane (CH4) emission by enteric fermentation has become indispensable for dairy production systems. The aim of this study was to evaluate CH4 emissions from pure Holstein (HOL) and 1/2Jersey 1/2HIn recent years the concern with methane (CH4) emission by enteric fermentation has become indispensable for dairy production systems. The aim of this study was to evaluate CH4 emissions from pure Holstein (HOL) and 1/2Jersey1/2Holstein (JH) high producing lactating cows grazing two different forages