The overall purpose of this thesis is to understand the impact of management on commercial egg layers, whether that be environmental-related, health-related, or other possible stressors within the pullet and post-peak phases. Furthermore, the study seeks to examine what effects to performance and production these impacts may induce within a commercial layer in differing phases, specifically the pullet and post-peak phases. Chapter two explores into coccidiosis within the pullet phase, which induced by a commercial vaccine, can provide stress to a pullet, lowering protection against infection, and seriously compromising its growth and development into peak lay. Chapter three explores into the post-peak phase, a transition from a caged system of production to cage-free system of production was selected. incorporating multiple differing environmental stimuli that can induce stress. If commercial layers prove to possess the capabilities to adapt to these impacts in multiple phases, the possibility of extended production is possible.