81 surgically castrated male growing finishing pigs (PIC genetic) with an average initial body weight of 45.4 ± 2.5 kg were
used untilthe slaughter weight of 114.4 ± 4.2 kg. Pigs were housed in nine identically constructed gas-tight sealed chambers.
Each chamber contained three pens with a surface area of 3.55m2
(2.43m× 1.46m).