Chicks from a high and low feather pecking line of laying hens differ in apomorphine sensitivity.

Proactive rodents show a larger behavioral response to apomorphine (APO) than reactive copers, suggesting a more sensitive DA system in proactive individuals. Previously, chicks from a high feather pecking (HFP) and low feather pecking line (LFP) have been suggested to display a proactive and reactive coping strategy, respectively. Therefore, at approximately 4 weeks of age, the behavior of 48 LFP and 48 HFP chicks in response to an APO injection was studied using an open field.

The control of feather pecking by serotonin.

Feather-pecking behavior in laying hens (Callus gallus) may be considered a behavioral pathology, comparable to human psychopathological disorders. Scientific knowledge on the causation of such disorders strongly suggests involvement of the serotonergic (5-hydroxytryptamine; 5-HT) system in feather pecking. Previously, chicks from a high-feather-pecking (HFP) line were found to display lower 5-HT turnover levels than chicks from a low-feather-pecking (LFP) line (in response to acute stress; Y.

Adrenocortical reactivity and central serotonin and dopamine turnover in young chicks from a high and low feather-pecking line of laying hens.

Feather pecking in domestic fowl is a behavioral abnormality that consists of mild or injurious pecking at feathers of conspecifics. Previously, it was shown that chicks from a high feather-pecking (HFP) and low feather-pecking (LFP) line of laying hens already differ in their propensity to feather peck at 14 and 28 days of age. As a first step in investigating a possible relationship between the development of feather pecking and physiological and neurobiological characteristics of laying hens, two subsequent experiments were carried out.