INSTITUTO DE DIVERSIDAD Y ECOLOGIA ANIMAL
Unidad Ejecutora - UE
Influence of the rearing system on yolk corticosterone concentration in captive Greater Rheas (Rhea americana).
BUSSO J.M.; MARTELLA, M.B.; MARIN R.H.; NAVARRO, J.L.; DELLA COSTA, N.; HANSEN C.
WILEY-LISS, DIV JOHN WILEY & SONS INC
Lugar: New York; Año: 2016 vol. 35 p. 246 - 246
Many environmental conditions elevate plasma corticosterone in laying birds, leading to elevated hormone accumulation inthe egg. We investigated whether maternal yolk corticosterone levels in Greater Rheas differ between fresh eggs collectedfrom an intensive (IRS) and a semi-extensive (SRS) rearing system. After HPLC validation, yolk corticosterone wasmeasured using a corticosterone 125I radio-immunoassay kit. Results (mean SE) showed that eggs collected from the IRSexhibited a significantly higher corticosterone concentration than eggs from SRS (89.88 8.93 vs. 45.41 5.48 ng/g yolk,respectively). Our findings suggest that rearing conditions under an intensive scheme (e.g., small pens with bare ground, nodirect foraging and handling) might be perceived as more stressful for Greater Rhea females than semi-extensive rearingconditions (e.g., low animal density distributed in extensive areas and direct foraging), which would result in the transfer ofhigher yolk corticosterone levels. A better understanding of environmental conditions and female traits that affect yolkcorticosterone deposition provides a background for future studies concerning the roles of maternal corticosterone onoffspring development.