Interpretive Summary: Keel bone damage affects behavioral and physiological responses related to stress and fear in two strains of laying hens

By: Haidong Wei, Yanru Feng, Susu Ding, Haoyang Nian, Hanlin Yu, Qian Zhao, Jun Bao, Runxiang Zhang

Keel bone damage (KBD) impairs production performance, welfare, and health in laying hens. This study aimed to compare the incidence of KBD and investigate the effects of KBD on stress and fear in two strains of laying hens. The results showed that commercial Hy-line Brown laying hens had high egg production and low incidence of KBD compared with Lindian chickens, a Chinese native breed. Besides, Lindian chickens had higher blood serotonin content and fear responses to human approach test and novel object test than Hy-line Brown laying hens. In addition, laying hens with keel bone fractures had elevated concentrations of blood corticosterone, interleukin-1β, and interleukin-6, and had a longer duration of tonic immobility and latency to approach a novel object, as well as reduced blood serotonin content compared with laying hens with normal and deviated keel bone. Overall, keel bone fractures caused stress and fear responses, impairing hen welfare; and behavioral and physiological responses in relation to stress and fear differed between strains of hens.

Read the full article on the Journal of Animal Science.