Pullets undergo rapid physical and behavioral development during rearing. Their skeletal structure, muscle tone, and behavioral repertoire develop in response to their rearing environment. Pullets reared in barren, low-stimulation environments show welfare deficits — particularly higher rates of keel bone fractures and floor laying — that persist throughout lay.
Pullets reared with perches use perches as adults. Pullets reared with nest boxes use nest boxes reliably at the onset of lay. Dust bathing substrate in rearing leads to better dust bathing behavior in lay. The rearing environment is an investment in adult behavioral welfare with measurable, lasting effects.
Osteoporosis and keel bone fractures are leading welfare problems in laying hens. Pullets given adequate exercise — space, perches at different heights, movement-encouraging environments — develop stronger bones and better proprioception. Rearing in multi-tier aviary systems produces stronger, better-coordinated hens.
Infrared beak treatment at 1 day of age (replacing hot blade trimming) reduces the risk of cannibalism and feather pecking later in life. While the procedure causes acute discomfort, it is less painful and has no long-term welfare impacts compared to hot blade trimming. Beak treatment welfare remains a priority concern for high-welfare production systems.
Establishing stable social hierarchies during rearing reduces aggression during lay, particularly at flock transitions (moving from rearing to laying facility). Managing flock size, mixing practices, and environmental complexity during rearing reduces feather pecking and improves social welfare outcomes.
Third-party welfare certification schemes (Freedom Food/RSPCA Assured, Certified Humane) now include pullet rearing standards. Auditors check rearing environment, mortality rates, beak treatment practices, and behavioral indicators. Alignment of rearing and laying welfare standards is a growing focus of industry and advocacy collaboration.