The effects of acute transportation stress on the adrenal gland of the domestic chicken (Gallus domesticus)

Abstract

An experiment was conducted to examine the effects of two types of cages and acute transportation stress on selected physiological and biochemical parameters of the adrenal gland of the chicken (Gallus domesticus). The experiment was conducted during the period from December 2010 to February 2011. The twelve chickens were divided into three groups (C1, T1, and T2). The chickens were caged in two types of cage: one was a standard wire-bottomed aluminum cage (95×60×70cm), and the other was a small plastic cage (68×48×20cm). In the C1 group, chickens were caged in standard wire-bottomed aluminum cage for 30min, with 2 chickens per cage and no transportation. In the T1 group, chickens were caged in standard wire-bottomed aluminum cage and transported for 30min, with 2 or 3 chickens per cage. In the T2 group, chickens were caged in small plastic cage and transported for 30min, with 3 chickens per cage. The cages were loaded onto open trucks and transported for 30min (T1 and T2). The plasma corticosterone (CORT) levels of transported chickens were significantly higher than those of controls (P<0.05); these results confirm that acute transportation has a strong stressful effect. Under these conditions, the highest plasma levels of CORT were found in the T2 group; however, these values were not significantly different to those of the T1 group. Western blot analysis of Phospho-Ser^<40> tyrosine hydroxylase and tyrosine hydroxylase in the adrenal gland did not show any significant differences between control and transported chickens. Thus, these results indicate that acute (30min) transportation stress in chicken induced a significant rise in plasma CORT, but the two different types of cages had no significant effect on plasma CORT levels in chicken during transportation at lower (between 4 to 5℃) temperature.