Natural News.com says that in response, USDA told Tyson to stop using the antibiotic-free label. The company has sued over its right to keep using it.

The controversy over Tyson's antibiotic-free label began in summer of 2007, when the company began a massive advertising campaign to tout its chicken as "raised without antibiotics." Already, Tyson has spent tens of millions of dollars this year to date in continuing this campaign.

After Tyson began labeling its chicken antibiotic-free, the USDA warned the company that such labels were not truthful, because Tyson regularly treats its birds' feed with bacteria-killing ionophores. Tyson argued that ionophores are antimicrobials rather than antibiotics, but the USDA reiterated its policy that "ionophores are antibiotics."

Because ionophores are not used to treat human disease, however, the poultry company suggested a compromise, accepted by the USDA in December, whereby Tyson would use a label reading "raised without antibiotics that impact antibiotic resistance in humans."

Tyson's competitors Perdue Farms Inc., Sanderson Farms Inc. and Foster Farms sued, under the banner of the Truthful Labeling Coalition. In May 2008, a federal judge ruled in their favor and told Tyson to stop using the label.

Natural News.com says that not long after, on June 3, USDA inspectors discovered that in addition to using ionophores, Tyson was regularly injecting its chicken eggs with gentamicin, an antibiotic that has been used for more than 30 years in the United States to treat urinary tract and blood infections. The drug is also stockpiled by the federal government as a treatment for biological agents such as plague.

"The use of this particular antibiotic was not disclosed to us," said USDA spokesperson Amanda Eamich.

The agency told Tyson that based on the new discovery, it would no longer consider the antibiotic-free label "truthful and accurate." It gave the company 15 days to remove the label from all its products, although that deadline was eventually extended to July 9.

But Tyson objected again, claiming that because the antibiotics are injected two to three days before the chickens hatched, the birds can truthfully be said to be "raised without antibiotics." USDA rules on how to label the raising of birds do not address anything that happens before the second day of life, the company said.

Tyson's response to Natural News.com story:

Tyson did initiate a Raised Without Antibiotics chicken program in 2007, and did so with what was believed to be appropriate government approvals. However, political pressure and legal action from competitors led to uncertainty and controversy over product labeling regulations and advertising claims. As a result, the company voluntarily chose to discontinue the program in the summer of 2008.

Tyson Foods says that contrary to the Natural News report, there is no pending litigation by the company against USDA and it is no longer producing chicken under a "Raised Without Antibiotics" label.

Like most companies in the poultry industry, including some involved organic chicken production, eggs are vaccinated before the birds hatch in order to prevent a virus known as Marek’s disease. A small amount of antibiotic is included in the vaccine to prevent cross-contamination between eggs during the vaccination process. According to USDA standards, chickens from eggs vaccinated in this manner can still qualify as organic, which is considered the gold standard for raising claims.

In it's defence, the company says that any use of antibiotics in its chicken production is under the direction of a veterinarian.