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Virginia Cooperative Extension - Knowledge for the CommonWealth

Thinking ahead about sexed semen

Dairy Pipeline: April 2002

Bennet Cassell
Extension Dairy Scientist
Genetics and Management
(540) 231-4762

I recently participated in a seminar on sexed semen, and learned quite a bit from Dr. George Siedel of Colorado State University about the current status of this technology. There is a procedure that works, though not without problems, and it is in the hands of a private developer. You may see semen bearing X or Y chromosomes on the market in the not so distant future. When (not if) that happens, be sure to verify that the product is produced by the right process. There are several questions about sexed semen that deserve attention. The present technology processes semen very slowly, meaning that the first "low dose" sexed semen to be marketed will contain many fewer live sperm than unsexed semen. Dr. Siedel's work has shown that, in the hands of careful, experienced, well-trained inseminators, low dose semen can be used effectively. The critical question is can those conditions be duplicated on your farm? Another question involves genetic merit of the bulls that produced the sexed semen. The equipment is quite expensive, it only works with freshly collected semen, and must be located very close to the site of semen collection. Further, semen on some bulls seems to sort more successfully than other bulls. Don't expect the early products to come from well-known, genetically superior, progeny tested AI bulls. The question for a potential buyer is, do I want calves sired by this bull, even if they are all heifers? A last question involves cost. Sexed semen will be sold for what the market will bear, but production costs of $50 or more per low dose unit ABOVE the base price of unsexed semen on the same bull should not be a surprise to buyers. While it is important to recognize the risks associated with emerging technologies, early adopters also reap the biggest financial benefits. Keep your eye on sexed semen. It will eventually be a reality.

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