Exports of U.S. beef to South Korea have dropped sharply this year on the whole, but a noticeable rise in shipments has been seen since April despite a confirmed case of mad cow disease in California that month.

The U.S. Meat Export Federation says some 51-thousand tons of U.S. beef were exported to South Korea this year as of late May, down 24 percent from 67-thousand tons during the same period last year.

However, U.S. beef exports to Korea rose in April and May by six-point-six and five-point-seven percent respectively, despite a sharp fall in the first three months of 2012 year-on-year.

The announcement of the mad cow case at a California dairy farm on April 24th caused significant controversy over U.S. beef imports in Korea, but trade data show the incident has had no major effect.