DICKINSON (AP) - Researchers have been testing radio identification tags on cattle, to see which frequencies work best.

"Other research centers and agencies are studying different frequencies, and we are in the position as one of the leads at this point," said Mick Riesinger, a livestock and biosecurity specialist at the North Dakota State University Dickinson Research Center.

The animal ID system is aimed at protecting against the spread of disease.

Larry Schnell, an owner of the Stockmen's Livestock Exchange in Dickinson, said the program, though not mandatory, is not popular with cattle producers.

"It's a pain and fairly expensive - and the cost is all on the producer," Schnell said. "It's just another job they have to do."

Riesinger tells ranchers that the goal is to track only the origin of the animal.

"All we're doing is tracking the animal ID for animal health," Riesinger said.

The low frequency ID tag does not register far, with a reading distance from 3 inches to 3 feet, he said.

"For low frequency tags, the animals have to be moved individually and restrained to get a 100 percent reading," Riesinger said. "The high frequency allows you to read at a distance from 6 feet to 20 feet away."

The high frequency tags were tested on animals in 10 different lots, with anywhere from two to 62 animals in each lot.

"We averaged .338 seconds per lot per reading," Riesinger said.

The tags used now are prototypes that are big and awkward, he said.

"What we were trying to do is take that tag and build it up to being a smaller tag," Riesinger said.