Embryo Transfer Background information
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American Milking Devon Cattle Association's Background Information in conjunction with a member survey on Embryo Transfer (ET) policies and procedures. By Drew Conroy, AMDCA PresidentJune 29, 2007 Many breed associations similar in size to our have struggled with this very issue. My comments below are not meant to be persuasive, but rather provide some background information on the use of Embryo Transfer and both positive attributes and areas of concern. Personally, I would like to see us allow Embryo Transfer, but do it in a way that ensures the embryos are what they are supposed to be. For a more comprehensive overview of the technology, I would recommend reading Training Manual for Embryo Transfer in Cattle, by George E. Seidel, Jr. and Sarah Moore Seidel, of the Animal Reproduction Laboratory, Colorado State University, Fort Collins, CO 80523, USA. Published by the Food and Agriculture Organization of the United Nations, as FAO ANIMAL PRODUCTION AND HEALTH PAPER 77, which can be viewed at http://www.fao.org/docrep/004/t0117e/t0117e00.htm Thoughts from: Don Bixby, of the American Livestock Breeds Conservancy would not recommend that we disallow this practice. In fact, he stated, "If we are allowing Artificial Insemination, there is a much greater chance of concentrating the gene pool, through the fact that we have not drawn many bulls, and the semen is readily accessible to many members due to its low cost. Phil Sponenberg explained, "Embryo transfer is 'value neutral ' really, but can have a VERY bad downside in rare breeds of narrowing genetic variation on the female side of the equation. So, it is best if recipients are not purebred cows. And, likely it is best to limit the numbers produced by an individual cow in any one year. Id do the same on the bull side, too, though. " Don Bixby has nothing against strong policies restricting its use, but he warned that this is not easy to do or get consensus on a policy within a breed association. The North American Devon Cattle Association has already interpreted our one year moratorium as a ban on ET, and perceived our survey of the membership to be in some way construed to be "small in our thinking". Interesting reading and the author's misinformation and opinions are quite malicious for an association trying to lure AMDCA members to join their association. see: http://www.northamericandevon.com/info.html#AMDA. It is one of the highlighted items, on June 14", the fourth item down from the top. Advantages of Embryo Transfer Technology for a breed such as the American Milking Devon:
Concerns in using Embryo Transfer include:
Recommendations, if members decide to support Embryo Transfer.
Given the above information, it would seem that at a minimum the association should likely require an embryo recovery certificate, which may also include:
There is also a need for similar testing for embryos as required by bulls for diseases prior to drawing semen, there is a similar need for health testing of cows used as donors, according to National Association of Animal Breeder standards. This will ensure that the embryos meet the requirements for international sale and shipping, plus provide an assurance of health of the embryos to the buyers. Summary In the case of small populations every animal counts and there can be a benefit realized from Embryo Transfer, but it is not the cure fora small population, as genetic diversity is important as well as animal numbers. There is the possibility of imposing restrictions on the number of calves from each cow that could be registered, as a way to minimize the possible effect that one cow has on the population, but again, this limitation would be similar to limiting the number of offspring allowed from a bull who has been drawn and used for artificial insemination, which the association has not ever addressed. One of the problems with selection of traits such as for milk production within a breed, is that the real value of the breed may lie in other characteristics that might be lost if there is increased specialty selection. At this time we have no verifiable production information on milk production or progeny tests on bulls, so selection will not likely be as intensive as it might be in other breeds. In any case, embryo transfer would allow possible inferior animals (for certain traits) to be propagated at a rapid pace, possibly displacing other more genetically superior animals for the same traits. Finally, the other challenge is that breeders with the best intentions may not get a cow that flushes well, despite the cost and efforts to do so. References: Phone Interview with Don Bixby, DVM, Technical Program Manager, American Livestock Breeds Conservancy (ALBC), Pittsboro, North Carolina, Monday June 11, 2007 Phone Interview with Marjorie Bender, Research and Technical Director, American Livestock Breeds Conservancy (ALBC), Pittsboro, North Carolina, Monday, June 11, 2007 Phone Interview with Jeannette Beranger, ALBC Research and Technical Program Manager American Livestock Breeds Conservancy (ALBC), Pittsboro, North Carolina, Monday, June 11, 2007 Email Message from D. Phillip Sponenberg, DVM, PhD, Professor of Pathology and Genetics Department of Biomedical Sciences, Virginia?Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA., June 20, 2007. George E. Seidel, Jr. and Sarah Moore Seidel, of the Animal Reproduction Laboratory, Colorado State University, Fort Collins, CO 80523, USA. Training Manual for Embryo Transfer in Cattle. FAO ANIMAL PRODUCTION AND HEALTH PAPER 77, Viewed on the Internet June 13 2007 at: http://www.fao.org/docrep/004/t0117e/t0117e00.htm |
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