Laying performance and fear response of White Leghorns as influenced by floor space allowance and group size.
Three experiments were conducted with White Leghorn pullets housed in litter-floored pens to determine the effects of floor space allowance and group size on laying performance and fear response. In Experiment 1, 17 birds were housed at a floor space allowance of .40 or .29 m2/bird. In Experiment 2, 22 or 16 birds were housed at a floor space allowance of .31 m2/bird. The following treatments were used in Experiment 3:1) 26 birds per pen at .19m2/bird, 2) 36 birds per pen at .19 m2/bird, and 3) 26 birds per pen at .26 m2/bird. The test 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, increasing group size per pen or a combination of the two had no significant effect on final body weight, hen-day egg production, feed efficiency, egg weight, albumen height, or fearfulness of the bird. Decreasing floor space per bird while holding the number of birds per pen constant significantly (P less than .05) increased mortality. Birds given less floor space consumed significantly (P less than .05) more feed than birds given more floor space in Experiment 1. This study indicates that the birds' hen-day egg production, feed efficiency, and fearfulness are not significantly (P greater than .05) influenced by floor space allowance or group size and that effects of floor space allowance and those of group size are not additive.
Lee
K
K
Department of Agriculture, University of Arkansas, Pine Bluff 71601.
D000704:Analysis of Variance; D000818:Animals; D001835:Body Weight; D002645:Chickens / Q000502:physiology*; D004435:Eating; D004528:Egg Shell / Q000648:ultrastructure; D004531:Eggs; D005239:Fear; D005260:Female; D006799:Housing, Animal; D010058:Oviposition