Corticosterone stress response of Greater rhea (Rhea americana) during short-term road transport

LECHE A.; DELLA COSTA, N. S.; HANSEN C.; NAVARRO, J. L.; MARIN R. H.; MARTELLA M. B.

POULTRY SCIENCE

POULTRY SCIENCE ASSOC INC

Año: 2012

0032-5791

The effect of transport stress on blood corticosterone levels in captive Greater Rheas was investigated. Twelve adult individuals (7 males; 5 females) were loaded in pairs inside wooden crates and transported along a paved road for 30-min. Blood samples were taken before the individuals were introduced into de crate (baseline value) and immediately after they were unloaded (30-min after capture). To assess whether corticosterone levels were affected by the blood sampling procedure per se, another 6 (non-transport) control birds (3 males; 3 females) were also captured and sampled at the same times as their transported counterparts. Plasma corticosterone concentrations were measured using a commercially available corticosterone 125I radio-immunoassay kit. Baseline corticosterone levels were similar in the control and transported birds (9.0 ± 1.6 and 10.4 ± 0.8 ng/mL, respectively). Transportation induced a highly significant (P < 0.001) more than 40-fold increase in the corticosterone levels (433.6 ± 35.4 ng/mL), that was about 5-times higher (P < 0.001) than in their non-transported counterparts (88.4 ± 14.8 ng/mL). The present findings suggest that Greater rhea is a highly sensitive species to stressful manipulations. Both blood samplings and transportation induced highly significant adrenocortical responses. Considering that transportation is one of the unavoidable common practices in the management of Greater rheas and, as shown in the present study, that it induces a significant 40-fold corticosterone stress response, efforts should focus on helping to generate management transport standards for optimization of the welfare of this ratite.