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 Highlight:
Insemination
Artificial insemination in the African elephant "Sabi" at
the Vienna Zoo - a tour behind the scenes
Hildebrandt TB, Göritz F, Fritsch G, Rohleder M, Schwarzenberger F, Schwammer H, Mohlin F, Tropeano A, Mitchell T, Hermes R.
The first successful artificial insemination (AI) in an African elephant
in Europe has been accomplished at the Vienna Zoo in 1999. While scientists,
the management of the Vienna Zoo and the Zoos' visitors were able to experience
the birth of the elephant baby ABU on 25.04.2001, international interest
increases in this new technique of modern reproduction management of elephants
in captivity. To meet the growing demand for background information, different
stages in the planning, the organisation and the safe and successful artificial
insemination of "Sabi" will be shortly summarised here. (www.zoovienna.at)
The most important elements of an AI program were 1. the ultrasound examination
and identification of suitable artificial breeding candidates, 2. the
prediction of the ovulation by ultrasonographic and endocrine oestrous
monitoring for the accurate timing of inseminations, 3. the collection,
assessment, processing and transportation of semen from a previously evaluated
potential breeder from the Colchester Zoo, UK and 4. the non-surgical
deposition of semen deep into the female genital tract.
- Selection of "Sabi" as candidate for AI
Fundamental to the planning of an AI was the identification of "Sabi"
as a suitable candidate for an artificial breeding attempt. The initial
transrectal ultrasound examination of "Sabi" by Drs. Hildebrandt
and Göritz from the Institute of Zoo and Wildlife research
(IZW) in December 1998 evaluated "Sabis'" reproductive health
status and put her individual characteristics on test. The state of
development and activity of the internal genital organs vestibule, vagina,
cervix, uterus and ovaries was first assessed by this ultrasound examination.
The evaluation of "Sabis'" reproductive soundness and an accidentally
documented imminent ovulation by ultrasound, retrospectively confirmed
by hormone analysis, made her an ideal candidate for an AI program which
was set up for March 1999.
- Prediction of Ovulation
Monitoring the oestrous cycle required weekly blood and faecal samples
which were analysed at the veterinary faculty of the Vienna university
and at the IZW in Berlin. Especially the blood sampling from the ear
or hind leg was part of the weekly routine and was taken on a fixed
day at a certain time. The hormone analysis of progesterone metabolite
concentrations in the faeces and blood gave basic information on "Sabis"
oestrous cycle length. During the follicular phase of the oestrous cycle
progesterone concentration is at baseline, indicating the development
of follicles on the ovaries at this stage of the cycle. The development,
maturation and ovulation of a Graafian follicle and subsequent development
of a corpus luteum marks the end of the 5 - 7 week follicular phase.
The Corpus luteum which derives from ovulation in association with accessory
corpora lutea is responsible for the synthesis of progesterone and the
steep increase of progesterone concentration in the serum or faeces
after ovulation. However, the determination of ovulation by faecal or
serum progestrone analysis is retrospective and therefore not appropriate
for an ovulation prediction and precise insemination timing.
The only method to predict the ovulation in elephants precisely, besides
a serum hormone analysis of the luteinising hormone (LH), not yet available
in Europe, was a daily ultrasound examination and evaluation of the ovaries.
Therefore, Dr. Hermes and Fritsch from the IZW performed serial ultrasound
examinations since mid-February 1999 to precondition the AI candidate
and more importantly to monitor the follicular development on the ovary
for accurate prediction of ovulation. Misinterpretation of a cystic structure
near "Sabis'" right ovary during the time of suspected ovulation
led to an incorrect reading of the ovarian dynamic during the first AI
attempt in March 1999. Taking the identified cystic structure under close
consideration, the second monitoring of a follicular phase in July 1999
resulted in an exact prediction of ovulation and subsequently to a successful
insemination.
- Semen collection, assessment, processing and transport
A potential male breeding candidate suitable for an AI program was identified
in the Colchester Zoo, UK. Similar to "Sabi", the reproductive
health status of the 18 year old male "Tembo" had to be evaluated
prior to the start of the project. During two visits to the Colchester
Zoo in January and February 1999 multiple ultrasound examinations and
semen collections by Drs. Hildebrandt and Hermes assessed "Tembos"
breeding potentials. The ejaculation in elephants is triggered by a manual
rectal massage of the pelvic part of the urethra and the accessory sex
glands located in that region. The collected ejaculatory fractions were
immediately examined for motility, progressive motility, concentration,
acrosome integrity and morphology of the spermatozoa. Excellent spermatological
results from these preliminary semen collections (e.g. 85 - 90% semen
motility) recommended "Tembo" as a reliable semen donor and
potential yet not proven breeder.
Main organising obstacle during the AI, apart from the prediction of ovulation,
was the still limited ability to preserve elephant semen over a longer
period of time. Different from domestic species such as cattle, where
semen can be collected, cryopreserved, transported and thawed at any given
day, elephant semen has to be collected, cooled, transported and inseminated
at the same day. During both AI trials in "Sabi" three inseminations
were scheduled on three successive days. Therefore, semen needed to be
collected from "Tembo" also on three successive days. "Tembos"
collected semen sample was assessed, extended with a specific nutritional
solution and transported from Colchester, UK to Vienna, Austria at 4°
C in a special thermo-regulated cooling container daily by the IZW team.
To underline the aspect of the insemination of a female never mated before,
Virgin-Airlines was in part carrier of the precious shipment. Herr Lienhart
form the Vienna Zoo was responsible for the outstanding co-ordination
of flights during both AI trials.
- Artificial insemination
The most important factor to the successful insemination was the tolerance
of the AI candidate herself, "Sabi". The non-surgical insemination
technique, which had been developed and patented at the IZW, required
1/2 - 2 hours steady standing on four specially made AI stands. The
fact that the insemination procedure was tolerated by "Sabi"
unchained and non-sedated, rewarded long term training efforts of both
the animal and the elephant handlers. This teamwork enabled "Sabi"
to support the insemination process by reflectory contractions of the
uterus at the moment of semen deposition, transporting the semen actively
deep into her genital tract. For the semen deposition in nulliparous
elephants close to the cervix a distance of 1.5 - 1.8 m from the genital
tract opening had to be covered. A specially designed balloon catheter
was first inserted into the vestibule and guided over the pelvic rim.
A video-chip-endoscope, placed in the lumen of the balloon catheter
by Dr. Göritz, visualised the hymenal structure and vaginal os.
This tiny vaginal os, which is exclusively observed in nulliparous females,
represented the greatest anatomical obstacle to overcome during the
AI in the nulliparous female. Through this 0.5 cm wide vaginal os, 1.3
m from the genital opening an insemination catheter 0.3 cm in diameter
was inserted into the vagina and placed close the cervical opening.
Simultaneous transrectal ultrasound by Dr. Hildebrandt verified the
exact positioning of the insemination catheter, before the warmed semen
was injected slowly. Olfactory stimulation of "Sabi" following
the insemination was achieved by urine, faeces and non-usable semen
factions from "Tembo". The first two artificial fathered African
elephant babies Amali (March 2000) and Ajani (August 2000) were born
at Indianapolis
Zoo.
Photography November 2000
The first two artificial fathered African elephant babies Amali (March
2000) and Ajani (August 2000) at the Indianapolis Zoo show what the Vienna
Zoo is awaiting after the birth of first European artificial fathered
elephant baby.
Latest news: AI-Baby born
On April 25th 2001 at Vienna
Zoo the little elephant bull "ABU" was born, weighing 110
kg at birth. He's exploring his new home with great empathy (Photo: Tiergarten
Schönbrunn, Wien).
 
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