A comparison of the behaviour of domestic chicks reared with or without a hen in enriched pens

Abstract

Studies on the behaviour of domestic chicks raised by a hen suggest that the hen has a major influence on the development of pecking preferences in the chicks. The absence of a hen for commercially reared chicks could therefore be crucial for the development of feather pecking. In the present study, it was tested experimentally whether the presence of a hen has a significant effect on the incidence of feather pecks in laying hen chicks (white ‘Lohman Selected Leghorn’ hybrids). Groups of eight chicks were reared with a hen (five groups) or without a hen (seven groups) in enriched pens over the first 8 weeks after hatching. There was a synchronization in the behaviour of the hen and the chicks both with respect to the activity performed (resting, exploring, feeding, preening) and the pen area used at a given moment. Chicks raised by a hen spent significantly more time feeding, less time standing and less time on the perches than chicks housed without a hen. Flight responses were significantly more frequent in chicks reared without a hen. There was no significant difference in the rate of feather pecking interactions between chicks reared with and without a hen. In both rearing conditions, the chicks already started to peck at the feathers of conspecifics in the first week of life. It is concluded that the presence of a hen does not prevent the chicks from directing pecks at the feathers of conspecifics and that factors other than the absence of a hen must be crucial for the occurrence of serious problems with feather pecking in commercial housing systems for laying hen chicks.