Understanding maternal behaviour in poultry
The identification of genes associated with broodiness could help select hens for egg production.
Poultry farmers have selected for improved reproduction for at least 2000 years, not least in an effort to increase egg production. Cessation of egg laying due to maternal behaviour, colloquially known as broodiness, is a major impediment and remains a problem for farmers in many parts of the world. Evolution of sophisticated agriculture allowed the separation of maternal behaviour from reproduction. In particular, the adoption of artificial incubation in Egypt 3000 years ago led to lines of chickens like the white leghorn, known for the absence of maternal behaviour.
By comparing white leghorns with silkie chickens, which have very strong maternal behaviour, it has been possible to identify loci on chromosomes 1, 8 and at the selective sweep on chromosome 5 that underlie selection against maternal behaviour and for egg laying persistency. This has increased understandings of maternal behaviour in poultry and is a basis for improving systems where maternal behaviour still reduces egg laying.
Basheer A, et al. (2015) Genetic loci inherited from hens lacking maternal behaviour both inhibit and paradoxically promote this behaviour. Genet Sel Evol.; 47:100. http://gsejournal.biomedcentral.com/articles/10.1186/s12711-015-0180-y