All cows were offered 3 kg per day of the same standard concentrate during milking in addition to the different mixed rations fed ad libitum. Production of CH4 was measured for four d in open-circuit respiration chambers in four periods during lactation: at 48, 125, 164, and 212 d in milk (DIM), and feed intake and milk yield were recorded at the same time. DIM did not affect DM intake (DMI)