cortisol
was greater in CAS males than in NC males (Figure
1) after treatment. A time × age interaction (P < 0.001)
was associated with serum cortisol; overall serum cortisol
was greater in the 9- and 12-d-old pigs than in the
3-d-old pigs (P < 0.01). Serum cortisol also tended (P <
0.07) to be greater in the 9- and 12-d-old pigs than in
the 6-d-old pigs. However, an interaction of age and
treatment was not observed for serum cortisol, as cortisol
dramatically increased in all CAS pigs regardless
of age by 0.5 h postcastration. At 24 h after castration,
serum cortisol concentrations returned to baseline in
both treatment groups regardless of age; however, at
48 h after castration, cortisol concentrations were increased
(P < 0.04) compared with baseline concentrations
in all age groups except the 3-d-old pigs.