Effects of Embryonic Norepinephrine on Juvenile and Mature Quail Behaviors

Poultry breeding flocks experience stress from numerous sources including feed restrictions, confinement, social aggression, changing environments, transport, and stockperson turnover. Maternal diet and stress can increase catecholamine levels, including norepinephrine (NE), and alter tyrosine metabolism. Elevated NE levels impact the embryo and lead to altered survival behaviors in the developed offspring. In order to determine the effects of NE on feeding and social behaviors, activity level, and fear response, Japanese quail (Coturnix japonica) embryos were injected with 10 μL of 0.01M or 0.05M of NE or saline at ED1 (n = 130) and incubated with intact controls (n = 80). Weekly behavioral scan samples (AM and PM) were taken from wk 4 (juvenile) to wk 11 (sexually mature) with rehoming between wk 6 and 7 samplings. Body weights were taken every other wk and organ weights were taken at wk 11. Tonic Immobility (TI) tests were conducted at 2, 5, and 9 wks. Results showed a greater incidence of eating behavior in birds that received 0.01M or 0.05M of NE compared to control birds, with eating frequency increasing over time in older NE-treated birds (P = 0.019 wk 5, 0.005 wk 10, 0.017 wk 11). Younger birds that received 0.01M of NE spent more time drinking compared to birds that received 0.05M of NE or controls (P = 0.013 wk 5, 0.016 wk 6). Birds that received 0.05M of NE foraged more frequently compared to birds that received 0.01M of NE (P = 0.002 wk 6, 0.046 wk 8, 0.002 wk 10, 0.009 wk 11). Following rehoming, NE-treated birds exhibited an increase in inactivity compared to control birds (P = 0.007, wk 7). Birds that received 0.01M of NE weighed significantly less than saline birds (P =0 .008 wk 3, 0.010 wk 5, 0.006 wk 7, 0.006 wk 9). Relative heart, liver, and spleen weights did not significantly differ (P = 0.412, 0.561, 0.293, respectively). We observed no difference in TI inductions (P= 0.637 wk 2, 0.475 wk 5, 0.349 wk 9) or duration (P = 0.108 wk 2, 0.426 wk 5, 0.730 wk 9). Our data show that NE injections during early embryonic development have lasting impacts on feeding and drinking behaviors, activity levels, and weight. These results suggest that maternal and environmental stress, including rehoming, impact both production and behavior with implications for poultry management.