A medicine manufacturer will gain full control of animal pharmaceutical company Merial, but the Gainesville plant will see little change.

The French drug company Sanofi-Aventis, which shares 50 percent ownership of Merial with New Jersey’s research pharmaceutical Merck & Co., announced Thursday that it will buy the rest of the shares after Merck and health care company Schering-Plough complete their merger.

Merial has an animal pharmaceutical research and distribution center in Athens and its avian vaccine center in Gainesville.

The plant employs 250 workers and remains the leader in the avian market, said Dennis Freeman, Gainesville’s director of industrial operations.

"Merial creates all types of animal vaccines, but this plant focuses on poultry," he said. About 90 percent of poultry nationwide are treated by vaccines made in Gainesville.

"We’ve recruited top research production scientists and marketing associates, becoming a key domestic supplier of vaccines and are now marketing internationally," he said.

The business move should have no effect on the Gainesville workers, officials said.

"It’ll be business continuing as usual," said Cheryl Ripka, manager of site services. "Nobody will really realize any difference."

Merial Select began business in 1971 as Select labs, a company started by "local poultry men here in Gainesville," Freeman said, including James Evans, Homer Wilson and Max Ward.

It first offered vaccines for Marek’s disease, a poultry virus, in Georgia and gained a federal license in 1980.

Merial’s North American headquarters moved to Duluth in 2000. The company has manufacturing sites in Maryland and North Carolina to raise poultry, and most are vaccinated while still an embryo.

The company now produces veterinary medicines such as Heartgard for heartworms and Frontline for fleas and ticks.