they were assigned
in groups of 12–13 to 1 of 8 pens (four per breed × 2 diets) to ensure
uniformity in age and body weight among pens. The pens included an
area with a roof, concrete floor and straw (bedded area) in front of the
feed bunk (which allowed all animals to eat at the same time) and an
external area of soil away from the feed bunk. The bulls were provided
with a continuous supply of freshwater, and they had permanent access
to mineral salt blocks. After a 14-day adaptation period, the two adjacent
feedlot pens within each breed were randomly assigned to one of
two feeding treatments. The treatments were a traditional diet comprised
of a concentrate mix and wheat straw offered separately (T),
or a total mixed ration made of the same concentrate mix partially replaced
with maize silage, and wheat straw (TMR)