The Food and Drug Administration will not say when it will announce the new safeguards that it promised four months ago to protect the U.S. animal feed supply from mad cow disease, a spokeswoman said on Friday.

The livestock industry has intense interest in the rules, with speculation rising every couple of weeks that an announcement was at hand. A new wave of rumors swept the commodity markets before FDA again said the rules were not ready for release.

In late January, FDA said it would swiftly publish detailed rules to carry out a series of new safeguards to protect the food and feed supply from the brain-wasting disease. The first U.S. mad cow case was found in a Washington state cow in December.

The FDA’s Center for Veterinary Medicine said there was no announcement planned on Friday.

“No announcement today,” said Rae Jones, a spokeswoman for FDA’s Center for Veterinary Medicine, and “no time frame for when announcement will be made.”

Earlier in the day, two food industry officials, who spoke on condition of anonymity, said the FDA could announce its proposed rules as early as Friday. They said the FDA may first publish regulations for the food supply, then issue the feed rules later.

A USDA official indicated to congressional staff on Thursday that FDA action was imminent, according to a Senate aide who attended the briefing.

Commodity traders at the Chicago Board of Trade were eagerly awaiting what regulations the FDA will propose. Soybean and soymeal futures were mostly lower as traders’ expressed disappointment that FDA wouldn’t make an announcement on Friday.

An FDA rule tightening the use of meat and bone meal in U.S. feed would boost soymeal demand.

“It’s probably a little disappointing to some soy bulls, but its impact on plant protein usage won’t be huge, said Jerry Gidel, analyst for North America Risk Management. “However, it’s getting a lot of attention because of the tight supplies.”

The FDA said on Jan. 26 it would ban animal blood in cattle feed, as well as ensure that dietary supplements and cosmetics are kept free of materials from cattle too sick or hurt to walk.

The FDA said it would also ban brain, skull and spinal material from cattle 30 months or older in FDA-regulated food and cosmetics. The measure reflects a similar U.S. Agriculture Department rule imposed on the meat industry in January.

Animal feed mills will be required to use separate equipment and facilities when processing materials prohibited in cattle feed.

The brain-wasting disease is believed to be spread when the remains of infected animals are used to make feed for other cattle.