Abstract

Predicting ovulations as precise as possible is crucial for the success and efficiency of artificial insemination procedures. In Tursiops truncatus aduncus ovulations have been successfully predicted using ultrasonography.^1,2 In Tursiops truncatus a luteinizing hormone (LH) assay technique used in canines and adapted to Tursiops truncatus has shown good potential for pinpointing ovulations.³ In Orcinus orca peak urine oestrogen conjugates concentrations have been used successfully to predict ovulations.⁶ Altrenogest treatment has been used with success to synchronize ovulations, however time from altrenogest withdrawal to ovulation was more varied as is desirable for efficient artificial insemination procedures.^4,5

In the Dolfinarium Harderwijk 4 females were treated with altrenogest 12 mg per animal (per os SID) for 35 days. Subsequently LH urine concentration was measured as described previously.³ Concurrently ovaries were monitored using ultrasound as described previously¹ Progesterone concentration was measured in serum using a sandwich chemiluminescent immunoassay (Diagnostic Product Corporation, Los Angeles USA, Immulite 2000).

All four animals were inseminated resulting in one pregnancy. Two of the remaining three non pregnant animals were inseminated again when their next ovulations were expected, resulting in another pregnancy. Two animals left not pregnant were given another altrenogest treatment and consequently inseminated but failed to cycle.

Four ovulations have occurred based on temporary or permanent rise (in case of pregnancy) of progesterone levels. Of these four ovulations three were correctly identified using ultrasound and three were predictable using the LH assay. Pregnancies were confirmed after 3 months by ultrasound.

Altrenogest treatment successfully synchronized 3 out of 4 females in May. Altrenogest treatment failed to synchronize two females in September. Resolution and usefulness of the ultrasound images heavily depended upon the thickness of the blubber layer overlying the ovaries.

This work would not have been possible without the support of the management of The Mirage and Grévin et Compagnie, the hard work and advice of the staffs of both institutions and Dr. Dennis Arn. It was truly a team effort.

References

1.  Brook FM. 2001. Ultrasonographic imaging of the reproductive organs of the female bottlenose dolphin, Tursiops truncatus aduncus. Reproduction 121, 419-428 Kinoshita et al. 2004. Artificial insemination in the indo-pacific bottlenose dolphin (Tursiops truncatus aduncus); Proceedings International Association of Aquatic Animal Medicine, 71-73.

2.  Muraco, et al. 2004. Qualitative analysis of a luteinizing hormone (LH) assay in the bottlenose dolphin (Tursiops truncatus). Proceedings International Association of Aquatic Animal Medicine, 59-61.

3.  Robeck TR. 2000 Advances in the understanding and manipulation of bottlenose dolphin reproduction in Report from the Bottlenose Dolphin Breeding Workshop Duffield DA and Robeck TR (Eds.) American Zoological Association Marine Mammal Taxon Advisory Group, Silver Spring, MD, 109-132.

4.  Robeck TR, et al. 2000. Preliminary investigations into ovulation manipulation techniques in delphinids. in Proceedings of the American Association of Zoo Veterinarians and International Association for Aquatic Animal Medicine, 222-225.

5.  Robeck TR, et al. 2004. Reproductive physiology and development of artificial insemination technology in killer whales (Orcinus orca) Biology of Reproduction 71, 650-660.