Feed intake and production in dairy breeds dependent on the ration.

Abstract

In 2 lactations and the dry period, with a changeover between lactations, Dutch Black Pied (DBP), Holstein-Friesian (HF) and DBP/HF crosses with 50% and 75% HF were offered roughage to appetite and 570 or 2310 kg concentrates per lactation. Energy intakes in the 2 lactations were 21 and 27% lower and roughage intakes 22 and 17% higher for cows given low-concentrates vs. high-concentrates; there was no carryover effect from lactation into the dry period when all cows received the same amount of concentrates. HF cows had higher roughage intakes than DBP by 4-5% but differences were only significant in late lactation. HF cows gave 10.1 and 7.2% (594 and 407 kg) more milk and 7.7 and 3.7% more milk energy than DBP cows in the 2 lactations resp.; this contrasts with a yield superiority of HF cows by 15% (974 kg) in the preceding lactation when concentrates were given according to milk yield. Milk yield was 20% (1250 kg) higher with high- than with low-concentrate; a carryover effect was noted at the beginning of the 2nd lactation. Efficiency of energy conversion to milk yield was significantly affected by ration at the beginning of lactation. Breed x ration interaction effects were not significant for intake or milk yield. (Abstract retrieved from CAB Abstracts by CABI’s permission)