The motivation of hens to lay eggs on the floor in non-cage systems has a heritable background

Abstract

Summary Large scale egg production in cages has been practiced worldwide for many years. However, recently consumer preferences have been shifting towards eggs produced in non-cage environments. In the March 2015 issue of Poultry Science a series of papers were presented from a comparative study of three production systems: conventional cages, enriched cages and aviary systems. Among the many issues reported we paid attention to floor eggs that is of no interest in cages but plays a role in enriched cages and in particular in aviary systems. The researchers called on attention to the cost of collecting floor eggs in the aviary systems and to the fact that floor eggs were more contaminated. In the Scandinavian Selection and Crossbreeding Experiment (SSCE) in 1980, birds were kept both in cages as well as in aviary systems for 5 generations. In this presentation we demonstrate that the frequency of floor eggs over 5 generations was reduced to 55% compared to the control line, and this was statistical significant. Although not being able to estimate the heritability it can be stated that some degree of heritability exists. In the meantime an electronically controlled nest has been developed. This would make it much easier for breeders to monitor individual egg laying behaviour of laying hens kept in aviary/floor management without the laborious work when using trap nests. By doing this, a more exact estimation of the genetic basis of laying floor eggs would be possible.