TOKYO, Dec. 12 (UPI) -- Japanese officials said a butter shortage threatening traditional Christmas sponge cakes was caused by cows being worn out by the hot summer.
Some stores are limiting butter purchases to one pack per customer and they have been posting "We have butter" signs whenever supplies are replenished.
Christmas cakes -- sponge cakes filled with whipped cream and strawberries -- have became a year-end staple in Japan, boosting demand for butter toward the end of the year.
The Ministry of Agriculture, Forest and Fisheries said the shortage was a result of cows being too exhausted by Japan's hot summer to meet their milk quotas. Farmers have also reduced production in recent years due to a falling demand, and the number of active dairy cows at the country's farms has dropped from 2.11 million in 1985 to the current total of 1.4 million.
Some Japanese bakeries said they have started using margarine instead of butter in the hopes customers would prefer the different product to inflated cake prices.