Choice of nest types by hens of three lines of broiler breeders

1. Choice of three different nest types by hens of broiler breeder lines was investigated: metal nests (26 x 29 x 33-45 cm, w x d x h) with inclined rubber mats, metal nests of the same size with litter, and larger wooden nests (30 x 40 x 38) with litter. Three lines were studied: line B (324 females + 36 males), line P (315 + 36), and line WM (306 + 32). Each line was housed in a pen 23.3 x 3.9 m (90.7 m2); half the area was concrete floor with litter, and the other half raised plastic slats, on which stood 84 nests, 28 of each type, in two-tier blocks. 2. Ninety-five per cent of eggs were laid in nests, with significant variation between types: 63% metal littered, 30% wooden littered, and 2.3% metal with inclined rubber mats. Choice between types was similar in the three lines. Hens of line B laid 66% of nest eggs in lower nests, P laid 57% and WM laid 64%. 3. The other 5.1% of eggs were laid on the floor: 1.2% on the litter and 3.9% on the slats in front of the nests. It is suggested that some subordinate hens were excluded from nests, and therefore laid on the floor.