Abstract

Collaborative efforts between zoos and aquariums have resulted in successful propagation in several captive cetacean species. Assay of blood progesterone (P4) can be used to monitor estrous cycles, determine the time of ovulation, help diagnose luteal insufficiency, and otherwise assist in the reproductive efforts in these species.^1,2 Blood P4 and other hormone results can be affected by sample handling conditions such as the type of blood tube used for collection and the length of time before centrifugation of the sample.^3,4 In this study, P4 results >0.2 ng/mL obtained from fifteen paired Pacific white-sided dolphin (Lagenorhynchus obliquidens) or beluga whale (Delphinapterus leucas) blood samples placed in different blood collection tubes were compared. Each blood sample was obtained by voluntary presentation during routine venipuncture or as part of a medical procedure and was divided into a gel-clot tube and a plain red-top tube. The paired samples were kept at room temperature until centrifugation at time points between 30 min and 15 h before being sent to an outside laboratory for P4 assay by chemiluminescence. Data were evaluated with a two-way ANOVA, using time until centrifugation (30 min, 1 h, >1 h) and tube type (RTT, STT) as discrete variables. Progesterone concentration was the dependent variable. There was a significant difference found for time (p=0.011), but not for tube type or the time*tube type interaction. Post-hoc multiple comparisons testing revealed a significant difference in P4 data between the 1 h and >1 h time variables (p=0.0114).

Acknowledgements

The authors wish to thank all of the technicians and trainers that assisted with sample collection and processing for this project and John G. Shedd Aquarium for financial support of this project.

* Presenting author

Literature Cited

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