THE 1930S
Research on moving hens to indoor living showed many benefits. While expensive, specialized henhouses resulted in much healthier birds. Hens weren’t exposed to predators and the elements. And indoor housing also helped to prevent parasite infestations and reduce the spread of diseases from outside carriers, including rodents and even humans. Better feeding practices also improved hen health and egg productivity.
These changes reduced hen mortality to 18% a year. But problems remained, including sanitation, waste control and the pecking order.