Are there ethical questions for the pigs?

Researchers think they may soon be able to grow human organs in pigs for use in organ transplants. Professor Hiromitsu Nakauchi, director of the Center for stem cell biology and regenerative medicine at the University of Tokyo in Japan told The Telegraph, that this is the ultimate and recent research proves it’s possible.

The researchers injected stem cells from rats into the embryos of mice that had been genetically altered so they could not produce their own organs, creating mice that had rat organs.
Researchers believe this could work in growing human organs in pigs as well. According to researchers the purpose is to help with the shortage of available organs for transplant patients. Again, The Telegraph:

Professor Nakauchi, who presented the study at the annual conference of the European Society of Human Genetics, used a type of adult stem cell known as induced pluripotent stem cells, which can be taken from a sample of tissue such as the skin and encouraged to grow into any type of cell found in the body.

Pigs have already been used to generate human blood by injecting blood stem cells from humans into pig fetuses. This could be a far-off cure for diabetics who often need pancreas transplants and a more realistic cure for kidney patients who have more lead time when they are in need of a transplant. This way they would receive a personalized organ. While the idea of helping with the diabetes epidemic and kidney failure couldn't be more positive, I can't help but to feel awful for the pigs that have to endure such treatment. Though there is no easy answer.