EFFECTS OF CAGE POPULATION ON THE PRODUCTIVE PERFORMANCE OF LAYERS

Two commercial layer strains (3,456 hens total) were used to examine t he effects of bird population on productive performance. Four cage pop ulation sizes (6, 8, 12, and 24 birds per cage) were compared. All cag es were 35.7 cm deep and varied in width (61.2, 81.6, 122.4, and 244.8 cm). Floor space per bird was 364.1 cm(2) and feeder space per bird w as 10.2 cm in each cage configuration. Egg production and egg quality were measured from 20 to 72 wk of age. Strain differences were detecte d in hen-day egg production, egg mass, feed consumption, cracked egg p ercentage, Grade A eggs, Grade B eggs, peewee eggs, and large egg yiel d. There were no interactions between strain and cage population size. Cage population had no influence on hen-day egg production, mortality , feed conversion, egg size (peewee, small, medium, large, extra large ), egg mass, lost eggs (by meat or blood spots), and percentage Grade B eggs. Percentage Grade A eggs, cracked egg percentage, and feed cons umption were significantly influenced by cage population size. Hens ho used at eight birds per cage had a greater percentage of Grade A eggs and a lower percentage of cracked eggs than those at other populations . Feed consumption was significantly greater for hens housed at 12 and 24 birds per cage compared with those at 6 and 8 birds per cage, resp ectively.