KIE: Jeremy Rifkin has filed a lawsuit to block U.S. Department of Agriculture (USDA) experiments involving the transfer of human growth hormone genes into sheep and pigs, which he rejects on environmental, economic, and ethical grounds. His real target is the Department's animal breeding program; his ultimate aim is "to establish the principle that there should be no crossing of species barriers in animals." USDA officials have not yet responded to the lawsuit but they intend to continue the experiments, which they consider crucial to the progress of research, until told to stop.