Last Christmas was one farmer Greg Lear would rather forget. “Yeah, some merry Christmas,” he said of the December 19th call from his farm manager with news that all the sows, or breeding females, were throwing up and many had diarrhea. The sows survived, but within 96 hours “we probably had 500 little pigs that were dead,” said Lear. As fate would have it, the Spencer, Iowa, farm he helps run was next in line to be hit by a virus that’s killed several million piglets across the country in the last 12 months. Rising pork prices have more than...