age-related scale). The four experimental trials (replicates)
consisted of two summer trials – trials 1 and 3 – in 1999
and 2000, and two winter trials – trials 2 and 4 – in 2000
and 2001. Each pen contained 5 pigs selected according to
treatment, initial weight, pen replicate, litter, and sex,
resulting in 160 Duroc · Danish Landrace · Large White
(DLY) crossbred pigs. Of these only 152 pigs were included
in the statistical analyses, as 8 animals were discarded during
production and slaughtering. Two were discarded due
to sickness and death and 6 due to wrong experimental
treatment. Of these 6 pigs, 4 were discarded due to mixing
pigs from two treatments in a pen after weighing during
the final production period and 2 due to wrong experimental
treatment during the slaughter process. Each trial consisted
of two pen replicates per treatment, and contained
3 castrates and 2 females in one pen and 2 castrates and 3
females in the other pen.
The relative levels of concentrate feeding refer to a scale