Commercial hatchery processing may affect susceptibility to stress in laying hens

Area of Science:

• Animal Welfare Science
• Poultry Science
• Behavioral Endocrinology

Background:

• Early life stress during commercial hatchery processing can impact the long-term coping abilities of laying hen chicks.
• Understanding these effects is crucial for improving poultry welfare standards.

Purpose of the Study:

• To compare the long-term consequences of commercial hatchery processing versus calm hatching conditions on laying hen chick stress responses.
• To investigate the effects of early life stress on physiological and behavioral coping mechanisms.

Main Methods:

• Comparison of commercial hatchery chicks (HC) and chicks hatched under calm conditions (CC).
• Exposure to stressors (transport, novel environment, regrouping) after 36 days of rearing.
• Assessment of tonic immobility, corticosterone levels, and peripheral body temperature (comb temperature).

Main Results:

• Tonic immobility was reduced in CC chicks post-transport.
• Comb temperature was higher in HC chicks post-regrouping, indicating stress-induced hyperthermia.
• HC chicks exhibited a stronger autonomic response to acute stress (comb temperature drop after blood sampling).

Conclusions:

• Commercial hatchery processing may have long-term negative effects on laying hen coping abilities.
• Calm hatching conditions appear to enhance resilience to later stressful experiences.
• Early life stress impacts physiological stress responses and coping mechanisms in poultry.