Cooking a delicious Thanksgiving turkey is as easy as pumpkin pie compared with breeding one, the Agriculture Department says.
Not only does the turkey have a brief egg-producing period, it makes the hormone prolactin, which causes anti-egg-producing behavior.While meat-type chickens can produce more than 280 eggs over the course of an entire year, the turkey only lays about 90 eggs during its 25-week egg-producing period.
In addition, turkeys can't start breeding until they are 30 weeks old. Meat-type chickens usually begin egg production in their 23rd week.
John Proudman, a poultry physiologist with the Agricultural Research Service's Germplasm and Gamete Physiology Laboratory in Beltsville, Md., said interfering with a bird's production of prolactin might spur the turkey to produce more eggs.
High levels of prolactin cause "broodiness," which means the turkeys sit on their eggs with the intent to hatch them, instead of producing more.
But if researchers could lower levels of prolactin, turkeys would spend most the day away from the nest, mixing with other birds, Proudman said.
To demonstrate his theory, Proudman injected active turkeys with prolactin. He said they became broody and stopped producing eggs.
Proudman estimates that if reduced levels of prolactin could increase egg production in hens by 10 percent, the industry would bring in an additional $30 million a year.
U.S. turkey growers raise about 4 million breeder hens annually. Those hens spawn 308 million turkey chicks, of which 292 million make it to market.
Proudman collaborated with Eric Wong of Virginia Polytechnic Institute and State University in Blacksburg, Va., and Mohamed El Halawani of the University of Minnesota to synthesize a gene that suppresses prolactin production. They are now trying to breed turkeys that would have the gene.