Cattle ranchers sue meatpackers, charge they depressed market.

Cattle ranchers have filed lawsuits against meatpacking giants ConAgra Foods Inc. and Cargill Inc., alleging the companies have used contracts and ownership of livestock to depress the market.

The ranchers claim the companies violate the Packers and Stockyards Act of 1921 by engaging in monopolistic practices.

The cattlemen also asked for an injunction to stop the packing companies from owning cattle or contracting for them in advance. Some sellers contend that as packers control more of the livestock supply, they bid less aggressively on the remaining cattle. USDA studies have concluded that the impact of captive sales on market prices is not enough to warrant government intervention.