Demonstrations and a threatened strike by the nation's farmers will not force the Carter administration to yield to farmers' demands for guaranteed profits, Agriculture Secretary Bob Bergland said yesterday.

"If we're going to guarantee parity as some have requested for, say hogs, we would have to invent a very complicated federal bureaucracy to replace the public market system. I don't think the people are ready for that," Bergland said on "Face the Nation" (CBS WTOP).

"Parity" is the price calculated to give the farmer a fair return in relationship to farming expenses. Many farmers, angered by low prices and hurt by bad weather, have begun to define a "fair return" as a guaranteed profit.

Bergland said the administration believes that "to provide a federal guarantee of the cost of production is about as far as the federal government should go" in supporting farm prices.

Asked if increased farmer militancy might force the administration to abandon its present position on farm support prices, Bergland said: "That's unlikely."

His comments came one day after farmers rallied in Washington, D.C., and in 30 state capitals to protest what they say are unacceptably low prices for their products. In a demonstration in Oklahoma City, a farmers hanged Bergland in effigy.

The ad-hoc American Agriculture Movement, which is leading the protest, has called on farmers to go on strike Wednesday by not selling or planting crops until their demands are met.

Bergland said such a strike would have a "substantial economic impact . . . if all of the 2 million or so commercial farmers joined in."

"Farming is the biggest business in the United States," he said.

Regardless of the issues in the dispute, consumers probably will have to pay more for food if the farmers are to be helped, Bergland said.

"The best thing the consumer has going is a strong, productive, healthy agriculture, and it's hurting - in places, it's hurting bad," he said. "On some farms, it's a disaster. The consumer is not going to be well-fed at a reasonable price if agriculture is driven into bankruptcy. Farmers have to derive an income from some place. That's a fact," Bergland said.

"How is it that you sound so sympothetic to the farmer, but you're the one who gets (hanged) in effigy?" the secretary was asked.

"(That's) because they don't know me," Bergland said.