UTRECHT, The Netherlands (Reuters) - Dutch researchers are trying to grow pork meat in a laboratory with the goal of feeding millions without the need to raise and slaughter animals. ... But it will take years before meat grown in labs and eventually factories reaches supermarket shelves. And so far, Roelen and his team have managed to grow only thin layers of cells that bear no resemblance to pork chops. Under the process, researchers first isolate muscle stem cells, which have the ability to grow and multiply into muscle cells. Then they stimulate the cells to develop, give them nutrients...