Slim Chickens: New Technique
To Measure Leptin Activity
Chicken meat is already lean, but
Agricultural Research Service scientists
have made a key genetic discovery that could help produce chickens with even
Chris Ashwell of the agency's Growth Biology Laboratory in Beltsville,
Maryland, recently discovered the presence of a protein called leptin in
chickens. Leptin has long been associated with obesity but until now had been
found only in mammals such as pigs, cows, mice, and humans. As a result,
Ashwell and colleagues Mark Richards and John McMurtry developed a technique to
study the hormonal activity of leptin in chickens.
Maximizing meat and improving production efficiency are major goals for
scientists studying chickens. That's because breeding broiler chickens for
growth has resulted in increased fat depositionand reduced reproductive
efficiencyin the birds. "What this means is that obesity is becoming
a problem in broiler chickens," Ashwell says.
Ashwell and his team hope to use their technique to find a way to regulate the
leptin levels in chickens and reduce the birds' appetites. This would make it
easier to manage broiler production and still provide consumers with quality
meat, Ashwell explains.
"Commercial industries may eventually use the technique to select birds
for feeding behavior that does not affect the growth of young birds," he
The technique, perfected by Richards and Ashwell, uses a method called
capillary electrophoresis to distinguish and quantify genetic material unique
to leptin. The process takes only 8 minutes. The team won an award from Beckman
Coulter, Inc., for achievements in capillary electrophoresis with this
Leptin, which regulates appetite and energy expenditure, can lead to extreme
obesity, diabetes, and infertility in mammals if the gene for leptin production
is defective. Leptin is found in fat tissue of mammals and chickens, but in
chickens it's also found in the liver.
"Two areas of importance to producers and consumers are increased chick
production and improved animal well-being," says Ashwell. Chicks with a
smaller appetite may provide a solution to these concerns."By
Sarah Tarshis, formerly with ARS.
This research is part of Animal Production Systems, an ARS National Program
(#102) described on the World Wide Web at