Super Animals The supermouse was created in the laboratory by Ralph Binster of the University of Pennsylvania veterinary school in 1983. He fused the human growth-hormone gene with a mouse gene to produce a mouse that grew twice as big as normal. It also passed on the growth trait to subsequent generations. Federal researchers at the USDA lab in Beltsville, Maryland, are attempting to do the same thing with sheep and pigs. Ohio University scientists are implanting genes in mice and rabbits and plan to try pigs. Colorado State University is working with cattle. Animals produced by these and other experiments would grow up faster on less feed, produce more meat and less fat, and suffer fewer illnesses, according to bioscientists.