vaccination
to slaughter (P < 0.0001) were observed. The ADG
of vaccinated pigs and intact boars was not significantly
different throughout the study, except from first to second
vaccination (boars greater; P = 0.0059) and second
vaccination to slaughter (vaccinates greater; P = 0.0390).
Feed conversion ratio of barrows was 11 and 8% greater
compared with vaccinated pigs (P = 0.0005) and boars
(P = 0.0062) from first to second vaccination but was
23 to 26% lower compared with vaccinated pigs (P <
0.0001) and intact boars (P < 0.0001) from first vaccination
to slaughter and 7 to 9.5% lower from the second
vaccination to slaughter (P = 0.0029 and P = 0.0003 for
vaccinates and intact boars, respectively). At slaughter,
the belly fat androstenone concentration of all vaccinated
pigs and 64% of intact boars was below 200 ng/g. Belly
fat skatole concentration was below 20 ng/g in samples
from all groups. In conclusion, vaccination against GnRF
using the GnRF analog-diphtheria toxoid conjugate tested
did not induce adverse clinical effects, proved effective,
and compared with physical castration, resulted in greater
BW at slaughter and improved ADG and