Agent Based Modeling to improve cage-free housing systems: What does the hen see?

Cage-free housing systems are changing constantly. Prior to May 2017, the term cage-free was not defined and establishing metrics for the laying hen industry and consumers were challenging. Cage-free is now defined: â¿¿Cage-free eggs are laid by hens that are able to roam vertically and horizontally in indoor houses, and have access to fresh food and water. Cage-free systems vary from farm-to-farm, and can include multi-tier aviaries. They must allow hens to exhibit natural behaviors and include enrichments such as scratch areas, perches and nests. Hens must have access to litter, protection from predators and be able to move in a barn in a manner that promotes bird welfare.â¿? (United Egg Producers, 2017). Cage-free housing has continued to evolve in the past 10 years as researchers have investigated different aspects of the housing system and bird behavior, such as nesting designs, substrates for dustbathing, perch designs, and even outcomes associated with stressors (Merrill and Nicol, 2005; Struelens et al., 2005, 2008; Scholz et al., 2010). However, all of these investigations are performed in an isolated environment instead of evaluating the entire system, and not taking into account the birdâ¿¿s biology and behavior. Housing systems have been designed taking to take into consideration human vision and labor, without regard for the henâ¿¿s visual system or how hensâ¿¿ perception of their environment influence how they use their environment. This is a critical gap that needs to be addressed so that an optimal cage-free housing system can be developed.