Wm. Kirk Suedmeyer, DVM
The African elephant (Loxodonta africana) is an endangered species with a poor history of successful breeding in captivity. Recent advances in artificial insemination provide hope for maintaining this species in captivity.4 The manual collection of semen in this species compared to electroejaculation negates the use of anesthetics, is generally more acceptable by elephant managers, and in at least a few instances has been demonstrated to be of higher quality than with electroejaculation methods (Loskutoff, personal communication).
An in-house study was undertaken to indirectly evaluate a physiologic “stressful” event (manual semen collection from an elephant in an elephant restraint device or ERD) through the pre-and post-collection evaluation of serum hydrocortisone levels. Corticoid levels are routinely correlated with stress in numerous species of animals.1,2,5,6 Complete blood counts (CBC) and select biochemical profiles were evaluated for any underlying disease process. Over the course of 1 year, 25 pre- and post-semen collection blood samples were collected and analyzed.
The elephant, a 22-year-old African bull elephant, was conditioned to enter the ERD on a routine basis. Once stationary, cargo straps were placed to prevent injury to the legs and hydraulically operated sides were closed to restrain the elephant. Ultrasonic evaluation of the reproductive tract3 had been performed prior to routine manual semen collection.
Blood was obtained from the saphenous vein immediately after the animal was restrained. The collection of semen was subsequently performed, and once completed (on an average of 20–40 minutes) blood was again obtained from the saphenous vein, placed in a serum separator tube, and processed routinely for analysis. Semen samples were cultured for aerobic and anaerobic bacteria and screened for viral particles with electron microscopy.
Serum hydrocortisone values were evaluated using a commercially available immunoassay (Dade IAC-TRI immunoassay, DPC Coat A-count cortisol kit). Results of serum hydrocortisone levels demonstrated a significant disparity initially but over time, pre- and post-collection samples correlated very closely. The CBC and serum chemistry results did not differ significantly over the course of the evaluation. No correlation with semen collection time was observed. Bacterial cultures of semen were negative. No viral particles were observed.
Over time, serum hydrocortisone levels demonstrated similar levels pre- and post-semen-collection. Reasons for this are unknown but may reflect accommodation to the procedure, diurnal or seasonal variations, changes in reproductive status, or other unknown influences. Longterm effects on semen quality are unknown. However, it has been noted with increasing frequency that the volume of sample has decreased with in-house manual semen collection. No other underlying cause of disease has been observed and no clinical illness has been observed. Further investigation of apparent accommodation by the elephant is necessary before additional conclusions can be made.
The first successful artificial insemination of an African elephant with extended semen was performed 3 years ago at the Indianapolis Zoo, with semen obtained from the Kansas City Zoo’s African bull elephant. As of this writing, the Kansas City Zoo has confirmed a natural pregnancy in one of its six African cow elephants. The due date is September, 2001.
The author would like to thank the Kansas City Zoological Park elephant care staff, Dr. Dennis Schmitt, and all of the people striving to succeed in saving the elephant from extinction.
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6. Robbins MM, Czekala NM. A preliminary investigation of urinary testosterone and cortisol levels in wild male mountain gorillas. Am J Primatol. 1997;43:51–64.