California and Arizona orange growers, despite the drop in the frostbitten Florida crop, are feeding millions of their navel oranges to farm animals to keep prices at the supermarket from dropping.

Market-limiting rules administered by growers' representives and sanctioned by federal law have kept about half the West's bumper crop of 1.6 million tons of navel oranges out of consumers' reach, a Consumers Union representative in San Francisco said.

On a drag strip in Famoso, Calif., rotting oranges are piled up several feet high after being rejected by a juice factory that had more oranges than it needed. Many of the oranges that cannot be sold are being dumped into cow pastures, "where the animals stomp around and eat maybe 10 or 20 percent of them," said one maverick San Joaquin Valley grower, Carl (Skip) Pescosolido.

Pescosolido said the commission controlling sales moved to fine him after he gave to some charity groups 1 million pounds of oranges he was not permitted to sell. "It's fear of the unknown," said Pescosolido, who controls about 2 1/2 percent of the area's navel orange market. "Most of the people here have never operated with any other system."

An Agriculture Department official and the manager of the Navel Orange Administration Committee both said the controls on orange sales were needed to protect small growers already in debt because of high production costs. Fruit and vegetable deputy head Donald S. Kuryloski of the USDA's agricultural marketing service said only 10 percent of the damaged Florida crops would have gone on supermarket shelves anyway, so Florida had little bearing on the California situation.

"We have doubted the consumption of oranges, and yet we're selling at the same price 10 years ago," said Billy Peightal, the committee manager. Most committee members are selected by the major orange growers and operate a system, created in the 1930s, of weekly limits on orange sales. Unlike other fruits, which are difficult to control because they must be sold as soon as they ripen, oranges can be left on the tree for months and picked in keeping with the committee's quotas.

"There are no notices or comment by the general public allowed," said Harry Snyder, director of the Consumers Union western office in San Francisco. "It's the OPEC of oranges."

While Florida crops have suffered from cold snaps, California and Arizona growers have reaped their largest harvest in history. Some western growers have complained that unseasonal rains produced smaller and less marketable oranges than usual, but Snyder and others dispute that. "It's just bull," said Snyder. "They taste just the same," said John Clark, a food and fruit and vegetable marketing specialist for the Agriculture Department here.

Many growers with more oranges to sell than permitted have sold the excess to juice factories, but such firms are now loaded both by the California excess crop and oranges picked quickly in Florida to save as many as possible after the recent freeze there. California navel oranges began to be harvested in November and December.They can remain on the trees until as late as June, but much of the late crop will go for animal feed.

A spot check of supermarkets in the Los Angeles and Washington areas found navel oranges selling at prices which grocers said were average or somewhat above average.

Peightal, manager of the committee that administers the marketing controls, said big growers like Pescosolido did not appreciate the problems of the majority of producers. "The average grower has less than 40 acres," he said.

The market control rules stem from Depression-era legislation that allowed cooperatives -- dominated by the huge Sunkist organization -- to ignore antitrust laws. Sunkist-affiliated growers' share of the market has declined from 75 to about 50 percent, Snyder said, but they still dominate the committee and insist on the artificial boost to prices.

Pescosolido said he thought concern for small growers was misplaced because only a minority of growers depended on their farms for their livelihood. "For some it's a hobby, for some a tax shelter," he said.

Pescosolido, a co-owner of the Exeter Orange Co. in a little town between Fresno and Bakersfield, said he has filed what is called a 15A petition asking the Agriculture Department to free him from the marketing controls. The request, which is expected to end up in the courts, will provide no immediate end to the system. A request by California lemon growers to be freed of similar controls is into its third year with no resolution in sight.