I have to admit, embryo transfers are a pretty creative idea. Take your very best, one-in-a-million dam , breed her, harvest her embryos to be carried by a lesser quality “surrogate” and repeat the process in a few weeks to maximize the offspring from that dam and utilize less desireable dams without passing on their genetics. Part really neat and part horrific sci-fi.
Do I need to repeat my waiver? Here it is just in case – I’m not a vet, none of this information is from any work I have done. I’m just passing on what I’ve found from published work. The predominance of the information on Embryo Transfer is from Dr. Jane Vaughan, directly lifted from either publications or her website, CRIAgenesis. So you could probably just click on the hyperlink and get the same information, just straight from the source, and without all the unnecessary filler that is , unfortunately, my only original contribution to this post. Even the picture (above left) of alpaca embryos, is from her website and I give full credit here.
Embryo transfer is in active use in Australia and New Zealand. It was pioneered by Dr. David Hopkins in 1986. The initial technique for alpacas was tested at Benleigh Alpaca Stud. Dr. Jane Vaughan, of CRIAgenesis, is an associate of Dr. Hopkins and defines ET as follows: :
“Embryo transfer (ET) is the process by which embryos are harvested from valuable female alpacas or llamas and transferred into less valuable females for incubation and nurturing. Each donor female is mated naturally by a male, which (a) induces her to release an egg into the oviduct and (b) deposits sperm in the female reproductive tract. The union of the egg and sperm (fertilisation) in the oviduct results in the development of an embryo, which can be harvested from the uterus about a week after mating. Donor females are lightly sedated and flushed non-surgically. Embryos are transferred into reproductively-sound recipient females of lesser genetic merit. The donor female can be mated and flushed in subsequent weeks to allow more embryo collections and transfers. Embryo transfer exploits the complementary genetic merits of elite male and female camelids and has the potential for major impact in genetic improvement and multiplication of the national herd. “
Dr. Vaughan has reported successful cria births as follows:
”Results to date in females that have not been superovulated:
231 donor females have been flushed and 164 embryos recovered (71 %).
164 embryos transferred into recipient females resulted in 96 pregnancies (58 %).
These results in females that have not been superovulated compare very favourably with other international laboratories that perform embryo transfer (von Baer et al. 2003: 58 pregnancies from 130 transferred embryos [45 %]).
Artificial breeding research is continuing in Australian camelids, with the development of multiple ovulation and embryo transfer (superovulation or MOET), embryo freezing and artificial insemination. These technologies will allow more flexibility in disseminating improved genotypes throughout the national herd.”
Superovulation is the growth stimulation of several follicles at a time through multiple doses of FSH (follicle stimulating hormone) over a period of time. Then ovulation is induced. The donor and recipient females’ reproductive status are synchronized through the use of GnRH (gonadotropin-releasing hormone).
The main advantage of ET is that it allows equal selective pressure on both the dam and herdsire side without decreasing production. However, the average cost per procedure is high and a relatively large percentage of the animal value in Australia. Also, the obvious dangers to the narrowing of the genetic pool must be considered along with the possible long term effects on the donor female, which are unknown at this time.
ET in the U.S. remains experimental and obscure. In 2001, Taylor Llamas worked with the LSU Ag Center Embryo Biotechnology Laboratory to transfer two alpaca embryos into two llama donor moms, resulting in the successful birth of alpaca crias. However, the LSU’s interest in this project was mainly to test out the technique for the purpose of using ET to save endangered species by using donor moms. Paul Taylor of Taylor Llamas, on the other hand, has spent over a decade researching ET and the possibility of freezing camelid embryos, both in his own lab in the US, and also in Chile and Argentina.
The viability of transporting frozen embryos for transport and sale has been a topic of research abroad. Protocols for this type of transport have been presented to the International Embryo Transfer Society (IETS). Current claims state that it is feasible to ship camelid embryos abroad, though the inability to register the resulting crias in the Alpaca Registry negates any U.S. interest in pursuing the validity of this technology.