Submitted to: International Society of Applied Ethology
Publication Type: Abstract Only
Publication Acceptance Date: June 10, 2000
Publication Date: June 10, 2000
Citation: CHENG, H., DILLWORTH, G.A., MUIR, W.M. GENETIC SELECTION-INDUCED ALTERATIONS IN EXPRESSION OF CATECHOLAMINE AND SEROTONIN IN CHICKENS. INTERNATIONAL SOCIETY OF APPLIED ETHOLOGY. 2000. P. 15. Technical Abstract: Alterations in endocrine hormones, such as catecholamine, are involved in controlling domestic behaviors in rodents and other mammalian species. The present study was designed to investigate effects of genetic selection on the expression of chickens' catecholamine and serotonin and how alterations in concentrations of these hormones relate to behavioral adaptations. Two genetic lines of chickens at age 20 weeks, the 7th generation after 23 years selection, were randomly assigned to individual cages; one line was highly cannibalistic (MBB) while the other was sedate and passive (KGB). Blood concentrations of catecholamine and serotonin were measured in these lines using HPLC assay (N = 24). Our data revealed that the chickens of the MBB line had higher concentrations of dopamine and epinephrine as compared to KGB chickens, 0.19 vs. 0.06 ng/ml (P<0.01) and 0.59 vs. 0.30 ng/ml (P<0.01), respectively. The concentration of norepinephrine was not significantly different between the lines but the ratio of epinephrine to norepinephrine was higher in the chickens of MBB line (72% vs. 34%, P<0.01). The concentration of serotonin was also significantly increased in the MBB line (1.43 vs.1.18 mg/ml, P<0.01). The lower baseline of these hormones in KGB chickens is consistent with data from previous studies that showed chickens of the KGB line had better adaptation than the MBB chickens in response to social, handling and environmental stress. This study indicated genetic selection for domestic behavior alters regulation of chickens' endocrine hormones, which may play an important role in improvement of bird's behavioral adaptability and well-being.