Cows were housed individually in tie-stalls bedded
with wood shavings, fed the experimental diets as a
TMR once daily at 0800 h, and had free access to water.
Feed was offered at 105 to 110% of actual feed
intake of the previous day. The amounts of feed offered
and refused were recorded daily during sample collection
periods. Samples of feed ingredients and orts were
collected daily during sample collection periods and
composited by period for feed ingredients and by period
and cow for orts. The DM concentration of barley silage
was determined, by drying samples in a forced-air oven
at 55°C for 48 h, twice weekly, and as-fed proportions
of feed ingredients were adjusted if necessary. Cows
were weighed after the morning milking but before the
feeding on 2 consecutive days immediately before the
start of the experiment. Cows were milked twice daily
at 0400 and 1500 h. Milk was sampled from both a.m.
and p.m. milkings on d 18, 19, and 20 of each period
of the study.