OREGON STATE UNIVERSITY

Newly found gene helps growers identify sex of turkey poults

08/29/1997

CORVALLIS - Oregon State University scientists have discovered a sex-linked gene in turkeys that may save millions of dollars in production costs by enabling growers to easily determine the sex of the birds immediately after they hatch.

"The gene retards development of feathers," said Tom Savage, OSU poultry science researcher and discoverer of the gene. "The expression of the gene in hatchlings ranges from sparse growth of feathers to complete absence of any feather development for the first few days of life."

The key to using the gene for sexual identification is that offspring showing the gene's effect are always the opposite sex of the parent bird transmitting the gene.

"This means that if the parent turkey carrying the gene is female, only the male offspring will exhibit the inhibited feathering trait and vice versa," said Savage.

"The advantage to using the gene on a large scale in turkey production is that the sex of progeny can be determined quickly and easily simply by observing the condition of the chick's feathers," he said.

Savage worked with doctoral student, E.I. Zakrzewska to develop a method of using the gene for sex identification with turkey hatchlings. Their study was recently published in the "Journal of Heredity."

Separating turkey chicks into male and female groups as soon as possible after hatching is important because each sex responds differently to feed components. Males are more efficient users of protein and grow faster than females.

"These days it's called a precision farming technique," said Savage. "Producers want to use feed as efficiently as they can and separating the birds by sex as soon as possible allows producers to provide the exact feed formula that each sex needs for optimal growth and economic performance."

The feather-inhibiting gene in turkeys is extremely rare. Savage first encountered it when an Oregon turkey producer brought him a female turkey that had failed to develop any feathers even though the bird was several months old.

"After mating the bird, the trait appeared in the offspring and I realized it was gene-caused and that the gene might be developed for use by growers," Savage said.

A similar process called feather-sexing has been used with broiler chickens for many years, according to Savage. But, feather-sexing turkey poults has not been possible until the discovery of the inhibited feathering gene.

Prior to the development of this technique, Savage explained, growers relied on a time consuming sex test for turkey chicks that required a technician trained to identify hard-to-detect sex traits.

"The cost to the growers for this service averages about two cents per poult, which doesn't sound like very much," said Savage. "But, when you consider that the U.S. turkey industry produced 300 million poults last year it's obvious that the cost of sexing all those hatchlings gets very high."

Savage has made the gene available to the turkey industry in the form of turkey semen that can be introduced into breeding stock.

"There has been commercial interest in the gene and one of the major U.S. producers is experimenting with it now," he said.