A menagerie of other genetically modified animals is in the works, promising what biotech backers say will be advantages like cheaper and more nutritious food. Borrowing genes from various creatures and implanting them in others, scientists are creating fast-growing trout and catfish, oysters that can withstand viruses and an "enviropig," whose feces are less harmful to the environment because they contain less phosphorus.

Pig farmers — and people who drive by pig farms — will soon be able to breathe more easily. Researchers at the University of Guelph have come up with a genetically engineered pig whose manure is not only sweeter-smelling but contains fewer pollutants than that of conventional hogs.

The three animals produced so far have been dubbed ''enviropigs.''

The smell is going to be there, regrettably," said Cecil Forsberg, a microbiologist who helped create the transgenic pig that will go by the trade name Enviropig. "That's task No. 2.