Researchers at Canada's University of Alberta have discovered a phenomenon that could, in future, help the breeding of chickens specially adapted for either meat or egg production.

The study found that broiler chickens have the ability to choose whether to use nutrients for themselves or to funnel them for egg production. The findings shed light on the phenomenon of "reproductive attitude", helping farmers better manage birds' body weight during puberty the egg-laying period that comes later. "The trouble with this is that these 'martyr birds' may eventually suffer from burnout when they don't balance their own needs well enough," said researcher Dr Rob Renema.