The same 120 piglets (63 females and 57 males) as described in  were used for this study. In addition to the ACTH stimulation test, previously described, each animal was injected in the neck muscles with LPS at 8 weeks (E. coli serotype 055:B5, Sigma-Aldrich, Saint Quentin Fallavier, FR) at a dose of 15 μg/kg body weight. Injections occurred from 10:00-11:00 AM to avoid nycthemeral variations. Blood samples were collected before the injection (t=0) and 1 h (t=+1), 4 h (t=+4) and 24 h (t=+24) after injection with the same protocol as described in .