ENOSBURG -- Sharon Zecchinelli raises a couple of pigs, lambs, turkeys and two dozen chickens in her back yard.

The 50-year-old chef-turned-farmer says she knows more about her animals' health than she knows about her children's.

To her, a federal government plan to require farmers and ranchers to register their animals in a national database goes too far. She remains skeptical about it, despite a recent announcement by the U.S. Department of Agriculture that participation in the National Animal Identification System, or NAIS, will be voluntary, not mandatory as originally contemplated.

"I raise animals for my own use. NAIS, or a program like that, would be good for the factory farms, which is where the food is being spoiled. ... We know our animals, and we know their health," Zecchinelli said.

The premise registration and animal identification idea, which is aimed at tracking animals to help prevent the spread of mad cow disease, avian flu and other diseases, has divided the nation's livestock farmers. Some see it as necessary for disease prevention, others say it would be onerous and an unwarranted intrusion by government.

Rick Parizo, a dairy and hog farmer in Milton, said he supports premise registration but not the tracking of every animal. "I'll sell my animals first before I let them come through and tag every single animal," he said.

To date, about 23 percent of ranches, farms, feed lots and other livestock facilities have registered their premises with the Agriculture Department.

Maine, Massachusetts, Texas and Vermont have decided not to require premise registration, while Indiana and Wisconsin have mandatory programs. Michigan will require premise registration for cattle starting in March.

"We've got very few people that want to have anything to do with animal ID," said Chuck Kiker, president of R-CALF USA, a western group that represents the interests of about 18,000 ranchers and cattlemen.

Kiker, a rancher in Beaumont, Texas, said he's pleased the Agriculture Agency backed off from the mandatory program.

"It's kind of refreshing to know that if so many people are against it, it can get beaten down," he said.

Some say the registration program would have unintended side effects.

"We do not need the government forcing this discriminatory program on producers who will gain nothing from it, but will lose their ability to produce locally grown wholesome food for their customers," said Richard Bean, president of the Virginia Independent Consumers and Farmers Association. "This program has the potential to destroy the sustainable agriculture and local food movement at the very moment that consumers are clamoring for our products."

Pork producers and the Holstein Association want a mandatory tracking system.

"We believe the program should be mandatory, because if it's not mandatory, it's not really going to work," said Dave Warner, a spokesman for the National Pork Producers Council. "It only takes one infected pig to possibly shut down our export markets and possibly spread the disease and affect the whole industry."

After widespread criticism, the USDA withdrew plans for mandatory tracking.

"Producers were really hung up on the mandatory versus voluntary issue," said Bruce Knight, undersecretary for marketing and regulation. "It was very clear to me that we needed to earn the trust of farmers." A voluntary program "would get us moving in the implementation of an animal ID program," he said.

The department's goal is to have 70 percent to 95 percent of ranches, farms and other operations with livestock registered by January 2009.

"We do believe we're going to have a high level of participation," said Ben Kaczmarski, a spokesman for the Agriculture Department, who said that in some cases, premise registration will become a prerequisite to doing business.

That's what worries Zecchinelli. She fears it will become more difficult for farmers who don't comply to get services or sell their animals.

"If you don't participate, you aren't going to be able to buy spring lambs or chickens without them being tagged, and you won't be able to sell them to your neighbors without becoming a criminal," she said.