June 5, 2007
Ark. Researchers Use Tubes to Study Cows
FAYETTEVILLE, Ark. -- Guessing about the contents of a cow's stomach is a thing of the past for University of Arkansas researchers - all they have to do is reach in and take a sample. The university's Animal Science Department has surgically implanted 4-inch-wide tubes, called cannulas, in the sides of 12 cows.
The cannulas allow the scientists to get a real-time look at a bovine's stomach contents in a study of the effect of grazing on nutrient run off into river watersheds.
On a recent visit, Professor Ken Coffey pulls out the plug of a cannula with an audible pop and reaches a fist into the cow to reveal the stomach contents. The cow stands placidly near a fence.
"See, this is what this cow's been eating just now," says Coffey, his hand filled with a green mulch that was once grass on the ground.
Coffey says he is accustomed to the public's curiosity and doesn't mind questions about the cows.
"Part of our role is to educate, and answering questions is part of that role," he says. "We've had kids come in from Rogers schools. Some put on a plastic sleeve and put their hands inside the cows."
The cannula lets researchers study how the cows use food during digestion. The stomach contents can be pulled out and examined, giving researchers clues as to how efficiently the cows are processing different types of feed, Coffey says.
The animals are anesthetized and the operation is typically performed by a veterinarian, says Shane Gadberry, an assistant professor of beef cattle nutrition with the University's Cooperative Extension Program in Little Rock.
"You're going to see (cannulas) utilized in a lot of university settings - Oklahoma State University, Kansas State University, University of Nebraska," he says.
The cannulas are implanted when the cows are young, between 600 and 700 pounds. Researchers sew the stomach lining to the cow's skin, providing an airtight seal with the cow's body. The seal must be tight because, if stomach acid leaks into the cow's body, the cow will die, Coffey says.
Repeated exposure to people makes the cows with cannulas well-suited for the experiment. They are more tame than other cows, making them easier to move from field to field and less disturbed by human contact, Coffey says.
Information from: The Morning News, http://www.nwaonline.net/