Energy corrected milk (ECM) yield was calculated using the following equation (NRC,2001): ECM (kg/d) = milk yield (kg/d) × {[0.3887 × milk fat (%)] + [0.2356 × milk protein − urea (%)] + [0.1653 × milk lactose(%)]}/3.1338 MJ/kg. Residual feed intake (RFI) used to examine feeding efficiency was calculated on a daily basis as: RFI(kg DM/d) = DMI (kg DM/d) − predicted DMI (which was calculated according to the NRC (2001) equation: predicted DMI(kg/d) = (FCM*0.372 + BW0.75*0.0968*(1 − e(0.192*(week in lactation+3.67)). The animal performance and digestibility study wascarried out according to the guidelines and under the supervision of the Agricultural Research Organization Animal Care Committee.