Birds were housed in 36 digestibility cages (6 replicates/treatment),
consisting of a wire bottom with a plastic tray for excreta collection,
a feed trough in front and a drinking cup at the back side.
The trial
was carried out according to the EU-reference method (Bourdillon et al., 1990) and consisted of preperiod of 8 d to adapt to the respective study diets (d 16 to 24) and a 4-d balance period (d 24 to 28).