Effects of storage time on hatchability of artificially incubated Greater Rhea (Rhea americana) eggs

Abstract

1. A study was conducted to determine the effects of the length of the storage period on the hatchability of artificially incubated Greater Rhea eggs. Hatchability was evaluated in eggs gathered daily from a captive population and in eggs collected less frequently from a semi-captive population.

2. Eggs form both sites were either immediately incubated after being collected or were stored for 1 to 9 d prior to incubation.

3. The maximum number of days for which an egg could be stored without depressing hatchability (with respect to non-stored eggs) was longer in the eggs collected daily.

4. Eggs collected daily and stored for 4 d or more showed total hatchability (28%) and fertile hatchability (43%) which was approximately 30% lower than non-stored eggs or eggs stored for 3 d or less. In the semi-captive population, the total and fertile hatchability of non-stored eggs and of eggs stored for one day were 40% greater than of eggs stored for 2 to 9 d (20 and 34%, respectively).

5. The period for which Greater Rhea eggs could be stored without depressing hatchability varied depending on the frequency of egg collection: non-daily egg collection reduces the possible period of storage.

Acknowledgements

We are grateful to the Córdoba Zoo and Repsol/YPF for allowing us to conduct part of this research on their properties. We thank J.M. Busso and G.M.M. Giacone for helping us with the English. The authors were supported by the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and the Universidad Nacional de Córdoba. This work was funded by grants to Dra. M.B.M. from the Agencia Córdoba Ciencia S.E. (formerly Consejo de Investigaciones Científicas y Tecnológicas de la Provincia de Córdoba), the Secretaría de Ciencia y Técnica de la Universidad Nacional de Córdoba, and CONICET.