In saline areas livestock are often offered food and water with high sodium contents and there is evidence for major effects of the sodium content of feeds on their palatability, ingestive behaviour and the performance of ruminants (Youssef et al 1993). The aim in this experiment was to examine whether calves could be conditioned to accept high sodium feeds by early experience.

Sixteen dairy Friesian heifer calves, aged 7 days, were allocated to receive their ad libitum concentrate feed with or without 27g added Na/calf/day, up to weaning at 6 weeks. The daily concentrate and water intakes were recorded for each calf until weaning time. The behaviour of calves was also observed for 12 hours per week at 8 min-intervals throughout the weaning period. At 6 months of age, calves were offered silage with added sodium, to give 0.1, 0.3, 0.5, 0.7, 0.8, 1.1, 1.3 and 1.5% sodium content in the DM. The daily silage intake for each calf was recorded for 2 weeks, beside observing the ingestive behaviour of calves for 24 hours at 3 min - intervals.