For decades, attempts to breed elephants using artificial insemination (AI) have failed despite considerable efforts and the use of various approaches. However, recent advances in equipment technology and endocrine-monitoring techniques have resulted in 12 elephants conceiving by AI within a 4-year period (1998)(1999)(2000)(2001)(2002). The successful AI technique employs a unique endoscope-guided catheter and transrectal ultrasound to deliver semen into the anterior vagina or cervix, and uses the ''double LH surge'' (i.e., identifying the anovulatory LH (anLH) surge that predictably occurs 3 weeks before the ovulatory LH (ovLH) surge to time insemination. This study describes the 6-year collaboration between the National Zoological Park (NZP) and the Institute for Zoo Biology and Wildlife Research (IZW), Berlin, Germany, that led to the refinement of this AI technique and subsequent production of an Asian elephant calf. The NZP female was the first elephant to be inseminated using the new AI approach, and was the fifth to conceive. A total of six AI trials were conducted beginning in 1995, and conception occurred in 2000. Semen was collected by manual rectal stimulation from several bulls in North America. Sperm quality among the bulls was variable and was thus a limiting factor for AI. For the successful AI, semen quality was good to excellent (75-90% motile sperm), and sperm was deposited into the anterior vagina on the day before and the day of the ovLH surge. Based on transrectal ultrasound, ovulation occurred the day after the ovLH surge. Pregnancy was monitored by serum and urinary progestagen, and serum prolactin analyses in samples collected weekly. Fetal development was assessed at 12, 20, and 28 weeks of gestation using transrectal ultrasound. Elevated testosterone measured in the maternal circulation after 36 weeks of gestation reliably predicted the calf was a male. Parturition was induced by administration of 40 IU oxytocin 3 days after serum progestagens dropped to undetectable baseline levels. We conclude that AI has potential as a supplement to natural breeding, and will be invaluable for improving the genetic management of elephants, provided that problems associated with inadequate numbers of trained personnel and semen donors are resolved.
Circulating patterns of progesterone and luteinizing hormone (LH) in the elephant have been well characterized, and routine monitoring of these hormones is now viewed as a valuable tool for making informed decisions about the reproductive management of elephants in captivity. Currently, LH monitoring in elephants is done with radio-immunoassays (RIAs); unfortunately, the use of radioactive materials in RIAs limits their application to institutions with laboratory facilities equipped for the storage and disposal of radioactive waste. Enzyme-immunoassays (EIAs) offer an inexpensive and more zoo-friendly alternative to RIA. This work reports on an EIA capable of quantifying circulating LH in African elephants. The EIA employs a biotin label and microtiter plates coated with goat anti-mouse gamma globulin. LH surges in African elephants (n=3) increased fivefold over baseline concentrations (1.0070.1 ng/ml vs. 0.270.1 ng/ml) and occurred 19.370.2 days apart. Ovulatory LH surges were associated with an increase in serum progestogens from 4.870.4 ng/ml to 11.770.4 ng/ml. The ability to quantify reproductive hormones in elephants via EIA is an important step in the process of making endocrine monitoring more accessible to zoos housing these species.
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