Behavioral Adaptation of Floor-Reared White Leghorn Pullets to Different Cage Densities and Cage Shapes During the Initial Settling-in Period

Two groups of White Leghorn pullets, reared in floor pens, were observed for changes in behavioral traits when housed in cages. Data in Experiment 1 were obtained during Days 1 to 5 posthousing from 40 pullets kept in eight 40.7-cm wide × 45.7-cm deep cages with either four or six birds/cage and in Experiment 2 during Days 1 to 5 and Day 7 posthousing from 24 pullets housed four/cage in three 30.5-cm wide × 45.7-cm deep cages (deep cages), and three 45.7-cm wide × 30.5-cm deep cages (shallow cages). In Experiment 1, pullets housed four/cage spent significantly (P<.05) fewer periods standing and crouching, but more periods preening, feeding, and performing comfort movements, than those housed six/cage. There was a significant group size × days posthousing interaction for standing and drinking. Standing was most frequent in the four-hen cages on Day 1 and then declined, whereas periods of standing increased in six-bird cages. Drinking behaviors were significantly different only on Day 1; six birds per cage had the lowest level. In Experiment 2, pullets in deep cages spent significantly more periods standing and moving and fewer periods crouching. Crouching frequencies declined from Day 1 to Day 7 posthousing for birds in both deep and shallow cages. Although there were significant cage shape × days posthousing interactions for all behavior observed, the interactions appeared to be associated with erratic day-to-day differences between hens in deep and shallow cages.