One of two cloned calves born last week died this afternoon. The genetically-engineered banteng calves — an endangered ox — were the product of a collaboration among Sioux Center-based Trans Ova Genetics, the San Diego Zoo and a Massachusetts company. Eric Woolson, a spokesman for Trans Ova, says the first calf continues to gain weight and is active, but the second calf had been in guarded condition since birth and took a turn for the worse today. Woolson says two vets decided early this afternoon to euthanize the calf. Woolson says it’s too early to speculate on the cause of the calf’s demise. Woolson says the Zoological Society of San Diego will conduct the post mortem, and it’ll be a couple of weeks before results are know. D-N-A from a banteng calf that died in 1990 was inserted into a cow’s eggs, and then implanted in a cow at Trans Ova facilities. Benteng are wild ox native to Java, an island in the Pacific Ocean that’s part of Indonesia.