A discrepancy in the rearing environments of young and adult laying hens
The environment in which animals develop is critical for optimal lifetime behaviour, health and welfare. Free-range laying hens are reared inside but receive access to an outdoor 'range' as adults. This discrepancy in environments between young and adult life stages may reduce the adaptability of adult hens to the outdoor ranging environment. This may have behavioural, health and welfare consequences for the birds.
Measuring the effects of enrichments
We conducted a study where we exposed 1400 laying hen chicks to different types of 'enrichments'. The enrichments were objects they had never seen before such as balls, buckets, ropes, strings, containers, plastic pipes, pet toys and children's toys. We also included specialised cube-shaped perching structures with select opaque panels. The enrichments were changed weekly over 16 weeks of rearing.
When they became adults, we measured their individual range use via radio-frequency identification technology that measured daily time spent out on the range area. We took periodic health and welfare measures on all birds through until the later period of laying production. We also measured behavioural and physiological responses to an environmental stressor and conducted behavioural tests of fearfulness.
From playing to roaming
Our research has shown that rearing environments can affect lifetime behaviour, health and welfare of free-range laying hens. Providing an enriched rearing environment increases outside range use and improves some health and welfare measures.
In addition, birds coped better with an environmental stressor after having been reared in an enriched environment.
This research contributes to our understanding of individual bird behaviour, health and welfare in free-range systems and rearing enrichments may be a strategy for optimising free-range production systems within Australia.