Researchers at the Ontario university have developed pigs that they say are healthier, slightly cheaper to produce, and potentially less harmful to the environment than conventional pigs.
Cecil W. Forsberg, PhD, professor emeritus in the Department of Molecular and Cellular Biology at the University of Guelph, is one of the researchers who developed the transgenic animals, known as Enviropigs. The animals contain a mouse parotid secretory protein promoter gene sequence and an Escherichia coli phytase gene, university information states.
"The social and ethical question is whether one additional gene and part of a promoter from another species really changes the pig—and in terms of the overall genome of the pig, that is very minimal," Dr. Forsberg said. "The other interesting thing is that, as far as the similarity of genes between mammals, they're all very similar. So in that sense, you're not introducing something that is very different from what's already there."
While conventional pigs require the addition of phytase to their rations to enhance digestion of phytic acid in cereal grains, the Enviropigs are modified to produce phytase in their saliva, Dr. Forsberg said.
"The Enviropig is able to metabolize the phytate, and, therefore, is able to satisfy its phosphorus requirement without the addition of phytase or supplemental phosphorus," he said.
The university began seeking approval from U.S. regulators in 2007 and Canadian regulators in spring 2009. While Dr. Forsberg said it seems the application has stalled in the U.S. during FDA deliberations regarding genetically engineered salmon, the university and Environment Canada have worked out conditions for production, and the university is seeking approvals from Health Canada and the Canadian Food Inspection Agency.
As a result, the university can produce the pigs but not sell them for human or animal consumption, and Dr. Forsberg said the pigs will not be moved from university facilities until they are approved for both.
University data indicate the pigs grow and reproduce without the supplements at least as efficiently as naturally occurring counterparts that receive the supplements, Dr. Forsberg said. While pork producers can save money on phytase and phosphorus, he thinks they will benefit even more by producing healthier pigs.
In addition, Dr. Forsberg said, the Enviropig name refers to the additional benefit of reduced phosphorus concentration in fecal material, which can leech into nearby bodies of water and promote algal growth. Weanling and growing pigs of up to 60 kilograms, or about 132 pounds, will produce manure with 50 to 60 percent less phosphorus, while older pigs will produce manure with about 30 percent less, he said.
Dr. Forsberg expects that consideration of AquaBounty's genetically engineered salmon is helping regulators determine which issues are important for consideration in genetically engineered foods, and he said it has been useful to read public comments during that process.
"And issues that the public has raised probably will spin into other analytical aspects that will be required, which may not have been apparent to the FDA scientists," Dr. Forsberg said.
The researchers are giving people an option, Dr. Forsberg said, noting that the pigs could be particularly useful in countries with large human and animal populations. He said the university has had numerous inquiries from Chinese swine production companies.
"I think the major determinants probably will be societal issues," Dr. Forsberg said of the Enviropigs. "That's all I see with the transgenic salmon from the science I have seen and the public response. It really is a societal determination."
Source: American Veterinary Medical Association