Japan eased the ban in 2006 but only for meat from cattle 20 months or younger. Japanese officials argued that the incidence of the disease was higher in older animals.

Aside from the reduction in exports, ranchers have also been grappling over the last half-dozen years or so with rising feed prices as ethanol producers drove up the price of corn, and with drought that has parched grazing land and deprived their animals of water. The recession and changing consumer tastes contributed to the woes. While the industry has had boom and bust cycles lasting on average four to five years, the current decline is firmly entrenched.

“Previous cycles of production and prices going back 100 years related to the particular workings of the beef industry and were usually self-correcting,” said Derrell Peel, professor of agricultural economics at Oklahoma State University. “But the current cycle is largely due to external factors and that is really why we are at this historic low.”

Cameron Bruett, the spokesman for one of the largest beef processors, JBS, welcomed Japan’s decision, saying it would help increase business certainty and reduce complexity for the company’s beef production, which operates in Brazil, Argentina, Canada and the United States. “While the declining herd remains a challenge for the industry, any time you increase access to additional consumers, that benefits the whole supply chain,” Mr. Bruett said.

JBS has eight processing facilities in the United States and Canada. While another major producer, Cargill, announced plans two weeks ago to close a plant in Texas, one of 10 it has in the United States, Mr. Bruett said JBS had no closure plans.