and born in the same origin farm within 48 hours. During
the first 3 days after birth, crossfostering took place in
order to equalise experimental litters to 10 piglets.
From each litter, six male and two female piglets were
chosen. Of these, two males were physically castrated
at 5 days after birth (PM), two males were vaccinated
with Improvac® (Pfizer Animal Health) by subcutaneous
injection in the neck at 74 and 145 days of age
(IM), and the other two males were left entire (EM) in
addition to the two females (EF). The six male piglets
from each litter were randomly assigned to the treatment
groups.