Genetic improvement in layers for egg production and quality

摘要

During the last few decades commercial layer flocks have shown significant improvements in terms of egg production and egg quality. The final goal of all breeding companies is to maximise the number of saleable eggs per hens housed taking into accountother aspects like health and welfare. For example, breeding companies mention that yearly genetic progress in total number of eggs produced at 80 weeks are between two and three eggs and for shell strength between 25g and lOOg.