Turkeys: The Good, The Bad, and The Fertile

Turkey breeders will be able to single out fertile toms using a technique that examines the swimming ability of a tom's sperm, an Agricultural Research Service scientist reports.

To measure turkey sperm movement, poultry physiologist Ann Donoghue modified a test that Oregon State University scientists originally developed for chickens. The test objectively measures what's called sperm motility--how well sperm from each male can swim into a solution at body temperature. The test mimics the environment the sperm encounter in the hen's reproductive tract.

Essentially 100 percent of the nearly 300 million turkeys produced annually in the United States for consumption are the result of artificial insemination. With advances in genetic selection, adult turkey toms can weigh up to 85 pounds. A hen, however, weighs only around 20 pounds when she begins to lay eggs. This size difference requires breeders to rely solely on artificial insemination for reproduction in their turkey flocks.

For artificial insemination of turkey hens, sperm are generally pooled from up to 10 to 15 males. So it's critical to know which males have the most viable sperm.

Information from these tests can be used to identify males that are very fertile. Likewise, the test can be used to identify "losers." In the past, most if not all semen evaluation tests have been much more effective at picking losers rather than winners. This test does both.

The potential to pick toms based on a test that correlates sperm motility with fertilizing potential could alter the way breeder toms are managed throughout the United States, Donoghue reports. By sorting out infertile toms, she estimates turkey breeders could save $5 million annually.

An in-depth story on this research appears in the July issue of Agricultural Research magazine. The story is also on the World Wide Web at:

http://www.ars.usda.gov/is/AR/archive/jul98/toms0798.htm

Scientific contact: Ann M. Donoghue is at the Germplasm and Gamete Physiology Laboratory, Bldg. 262, BARC-EAST, Beltsville, MD 20705; phone (301) 504-8580, fax (301) 504-8546, annie@ggpl.arsusda.gov.