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NOVEMBER/DECEMBER 2004 |
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And that's just the beginning. According to Steve Mower, Marketing Director of Cyagra, Inc., the Elizabethtown, Pennsylvania, company that has done it, the limits of cloning are about the same as the limits of one's own imagination. Right now, cloning is an expensive way to obtain replacement calves, but a multinational race is on to bring it within reach of both commercial and pedigree breeders. A Texas Longhorn breeder decided to clone an animal with seven-foot, seven-inch horns. The young clones are already on the ground and developing horns worth staying away from. Mower says that variations from the cloned foundation cow are expected to be small, possibly up to a five-inch difference in the length of the horns. These small differences are related to slight variations in the calves' birth weights, affected by the surrogate mother cow and not to the cloning process, Mower said. An Italian lab has produced a cloned colt of an Austrian Haflinger horse. An Idaho cloned mule is thriving, and while horse cloning is not as far along as dairy and beef clones, the prospect will almost certainly add a new element of excitement to horse racing when every horse in a race is a genetically identical clone of a single champion. Has there ever been a 16-way tie in a horse race?
Some producers who are not yet ready to invest in cloning are establishing cell lines on their best animals to assure that the genetics of those animals are preserved for future use. That investment could turn out to be far better than even the most explosive days of a bull market on the stock exchange. In the language of the scientist, the dairy genome is still being untangled. In layman's terms that means there's still a lot of detail work to be done. The information being uncovered will allow scientists to sort out the specific genes of a dairy animal for higher production as well as resistance to mastitis and other diseases. Because genes of any living organism can be placed into any other organism, the characteristics that can be placed in an animal are almost unlimited. So when a single animal receives this type of cross-species genetic manipulation it becomes a "transgenic." The transgenic animal then becomes the donor that can be cloned to build entire herds with that specific genetic characteristic. Cyagra has been producing cloned calves at its EmTran embryo transfer facility in Pennsylvania since 2001. The clones are an extension of an embryo transfer service that in the past has exported genetically superior dairy cow embryos around the world. Animals grown from those embryos have greatly increased milk production in British and Dutch Frisian herds. Mower explained that Cyagra is concentrating on non-transgenic cloning of cattle, pigs, sheep, goats, and horses. After the clone embryo is produced and successfully implanted into a donor female, and a healthy calf is born, he said it is exciting for the Cyagra staff to deliver a superior animal to the owner of that cell line. But right now there appears to be no rush to cover the world with superior cloned animals. Mower said that in the U.S., the Food and Drug Administration (FDA) has requested cloners not to market milk, meat, or semen from cloned livestock while they further evaluate the food and animal safety of cloning. The FDA concerns are mainly about the non-livestock aspects of the process such as transgentic or cloned fish and insects. Approval to go ahead with production livestock cloning is anticipated in the near future. Cloning is the logical scientific reproductive technology to follow the genetic advancements that have already been made since World War II, first with artificial insemination and more recently embryo transfer. North American dairymen first heard about the new artificial insemination technology in the mid-30s. It came out of Denmark, and it sounded impossible. It took a few more years before computers helped sort out the best bull genetics to make fullest use of A.I. potential. Embryo transfer came next and seemed equally astonishing. Embryo splitting and pre-implant sexing are now accepted practices. Cloning is a huge step ahead because it is non-sexual reproduction. The fibroblast gene cells used in cloning can come from a bull, steer, or cow. A small skin sample is enough for a million clones, Mower said. Collecting skin samples to establish the cell line has become a well established routine, according to Mower. But care must be taken so no human genes get into the sample. He grins as he stresses the importance of sanitation and rubber gloves for the person taking the sample from an animal. After all, what farm wife anywhere would want to accidentally get another copy of her husband?
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