Doctors in the USA have transplanted a pig's heart into a man. It is the first time this has happened. The doctors are from the University of Maryland Medical Center. They say David Bennett, 57, is doing well after his operation. Mr Bennett was very ill. The doctors said giving him the pig's heart was the only chance of keeping him alive. Bennett spoke to doctors the day before the operation. He said: "It was either die or do this transplant. I want to live. I know it's a shot in the dark, but it's my last choice." The pig's heart came from a genetically-modified pig. Scientists changed the genes of the pig so its heart would be more suitable for a transplant into a human.

The transplant operation took seven hours. Doctors received special permission from U.S. authorities for the experimental surgery. Without it, Mr Bennett would have died. Scientists have been researching pig-organ transplants for years. They believe Mr Bennett's transplant means more transplants could take place in the future. They said this could bring the world, "one step closer to solving the organ shortage crisis". Surgeon Dr Bartley Griffith said: "We are also optimistic that this first-in-the-world surgery will provide an important new option for patients in the future." Mr Bennett hopes his transplant will allow him to live longer. He said: "I look forward to getting out of bed after I recover."