Persistent effect of broody hens on behaviour of chickens.

We reported previously that behavioral development of chicks was promoted remarkably by the presence of a broody hen. Here we report that these effects at an early age persist after maturity. A total of 60 female chicks were randomly assigned to one of two treatment groups: six pens with five chicks (brooded group) each were reared by a broody hen and six pens with five chicks (non-brooded group) each were provided with an infrared heating lamp. We evaluated the persistent effects of broody hens by measures of behavior, physical condition and production at 9, 16, 35 and 55 weeks of age. The numbers of threatening, aggressive pecking, fighting and severe feather pecking behaviors were higher in non-brooded than in brooded chickens (all P < 0.05). Egg production was lower in brooded than in non-brooded chickens (P < 0.05), while the number of brooding chickens was higher in the brooded than in the non-brooded group (P < 0.05). In conclusion, the presence of broody hens at an early stage of chicks' lives has a persistent effect on behavior. Although brooded chickens showed more brooding and lower egg production than non-brooded chickens, feather pecking and aggressive interaction were decreased in brooded hens.