Space use at night and social relationship between roosting partners in a large flock of laying hens

Abstract

1. Laying hens in two aviary flocks of 1250 females and 12 males were investigated to determine if hens used the same roosting site more often than expected by chance and whether hens that roost next to each other for two consecutive nights (close groups) had fewer agonistic interactions than hens roosting far away from each other (distant groups) when put into a new environment in groups of 4 birds. 2. Hens showed a significant preference for using the same roosting site on consecutive nights. There was no difference between close groups and distant groups in agonistic interactions. However, in close but not distant groups, a low or high level of interaction on day 1 predicted a low or high level on day 2 that might reflect established relationships in the close groups. 3. It was concluded that hens prefer the same roosting site in the short term but further research is needed to investigate whether hens roosting next to each other recognise roosting partners or not.

Genome-wide association study of aggressive behaviour in chicken

“…It’s believed that, the problems associated with aggressiveness in broiler breeder males are genetic factors that produce differences in both general aggressiveness and sexual aggressiveness 6 . However, both genetic and environmental factors, including diet 7 , lighting conditions 8 , feeding methods, group size 9 , sex-mixed in a large flock of laying hens 10 , gender, and age, could modulate chicken aggressive behaviour. In chicken, an aggression-related heritability estimate value of 0.57 has been reported earlier by Siegel; in which selection trial of two-way was used to produce the next generation, and the selection is made with respect to only one parent for the selected trait from twice the ratio of change per generation to the average differential of selection 11 .…”