Mapping quantitative trait loci affecting feather pecking behavior and stress response in laying hens

Area of Science:

• Animal Genetics
• Animal Behavior
• Poultry Science

Background:

• European Union legislation is increasing for animal housing due to welfare concerns.
• Feather pecking (FP) in large group housing is a significant welfare issue in laying hens.
• Corticosterone (CORT) response to restraint is a potential indicator of stress linked to FP.

Purpose of the Study:

• To identify quantitative trait loci (QTL) associated with feather pecking behavior.
• To identify QTL associated with corticosterone (CORT) response to manual restraint (stress response).
• To understand the genetic basis of stress and feather pecking in laying hens.

Main Methods:

• An F2 intercross population of 630 laying hens was created from two commercial lines with differing FP tendencies.
• Behavioral traits (gentle FP, severe FP, aggressive pecking, toe pecking) and CORT response to restraint were measured.
• QTL analysis was performed using regression interval mapping on 180 microsatellite markers.

Main Results:

• Suggestive QTL for gentle FP were found on GGA10 (6 wk) and GGA1, GGA2 (30 wk).
• A significant QTL for severe FP was detected on GGA2 (30 wk).
• Suggestive QTL for CORT response were identified on GGA18 and GGA5 (with a potential maternal effect).

Conclusions:

• This study identified several suggestive and significant QTL associated with feather pecking and stress response in laying hens.
• These genetic markers can aid in breeding programs to reduce feather pecking and improve hen welfare.
• Further research can explore the identified QTL for precise gene identification and functional validation.