In cage-free egg production systems, concerns have been raised over hen mortality rates. High mortality is an obvious indicator of poor welfare, and problems should be addressed without delay. It is important to note, however, that mortality can vary substantially between hen flocks, and that some cage-free systems have healthy flocks that do not suffer substantial death losses. These systems can serve as models for the rest of the industry, since mortality is not inherent to any particular system, but a consequence of how well the system is managed.
The Humane Society of the United States, "Understanding Mortality Rates of Laying Hens in Cage-Free Egg Production Systems" (2010). Farm Animals, Agribusiness, and Food Production. Paper 3.