Two animal trials were carried out at the same private pig
farm. In each trial, twenty four piglets (Large White × Duroc),
from four litters were transferred after weaning (35 days) to
flat decks and were randomly allocated to 4 groups with 6
animals each (3 male and 3 female). Two piglets from
different litters (1 male and 1 female), with the same body
weight were housed in every box (experimental unit). The
litter origin was taken into account, avoiding that piglets from
the same litter were allocated in the same treatment. There