It was supposed to be a day for passing farm legislation in the House yesterday, but it went the other way: the Agriculture Committee laid an egg and the dairy cow escaped from the fiscal barn.

As a result, the law authorizing farm support programs was to expire at midnight and an administration effort to prevent a temporary $1-million-a-day increase in dairy price supports was derailed for the time being.

Chaos in the legislative barnyard ensued in two ways, first when the Agriculture Committee was unable to win approval of a rule setting terms for debate of its new four-year farm bill on the floor. The committee had hoped to finish action by early next week.

Then an effort to hurry along a stopgap measure to stall the midnight increase in dairy price supports was stymied when Rep. David R. Obey (D-Wis.), representing the nation's largest milk-producing state, objected to the emergency approach.

Department of Agriculture officials estimated that the failure of Congress to approve the proposed scaling down of the dairy program will cost taxpayers an extra $1 million a day in government purchases of surplus milk products until the law is changed.

Expiration of the current law at midnight automatically sent dairy price supports to $13.56 per hundredweight, as required by a 1949 authorizing act. The Senate-passed farm bill, backed by the White House, would hold dairy supports at $13.10.

Obey's objections sent Agriculture Committee leaders scurrying, and by late yesterday afternoon they won Rules Committee approval to go to the floor today with the proposal to keep dairy supports at the $13.10 level.

Agriculture Chairman Kika De La Garza (D-Tex.) said he will try to call the dairy price support delay to a floor vote today while he makes another effort to win a rule for the general farm bill.

Earlier yesterday, De La Garza failed to get a rule for the bill after Rules Committee members expressed dissatisfaction with proposed procedures for handling floor amendments to the measure.

"The Agriculture Committee didn't have its act together," said Rules Chairman Richard Bolling (D-Mo.). "The bill has a range of problems, but it was impossible to structure a rule that would have been fair to all under the procedures proposed by Agriculture."

De La Garza said that Bolling had instructed him "to get all my ducks in a row, but I've got ducks flying off in all directions." He said he may attempt to go before the rules panel again today with a new plan.

The Agriculture Committee had proposed a series of amendments to its bill that, according to De La Garza, would have reduced potential outlays by close to $1 billion and brought it within limits set by the first budget resolution.