Research Note: Effects of Floor Space Allowance and Group Size on Fear Response of White Leghorns

Abstract

Three experiments were conducted in litter-floor pens to study fear response of White Leghorn layers as affected by floor space allowance and group size. In Experiment 1, 37 birds were housed at a floor space allowance of. 18 or. 13 m2/bird. In Experiment 2, 50 or 36 birds were housed at a constant floor space allowance of. 14 m2/bird. The following treatments were used in Experiment 3:51 or 37 birds per pen at.13 m2/bird; and 37 birds per pen at .19 m2/bird. The study period was from 20 to 52 wk of age in each experiment. Duration of the induced tonic immobility, measured at 52 wk of age, was used as a criterion of fearfulness.Decreasing floor space allowance per bird or increasing group size per pen had no significant effect on fearfulness. Also, the effects of floor space allowance and group size on fear response were not additive under the conditions of this study.