Effects of herbage allowance and animal factors on intake by grazing dairy cows

摘要

Sources of variation in herbage organic matter intake (HOMI) by grazing dairy cows are not well quantified. These two trials studied the effects of Herbage Allowance (HA) and cows characteristics upon HOMI. In trial 1 (1988) two herbage allowances (HA) (Low and Medium, 19 and 26 kg OM/cow/d) were compared in a continuous design using two groups of five cows. In trial 2 (1989), three HA (Low, Medium and High, 19, 29 and 46 kg OM/cow/d) were compared in a 3x3 latin square design using three groups of five cows. Twenty five mid-lactating cows (six primiparous per trial) were used. Fat corrected milk (FCM) at turnout in April (Mpt) ranged between 17 to 35 kg and body live weight (LW) ranged between 510 to 680 kg.