One of the most hotly contested issues in modern agriculture revolves around the proposed use of a genetically engineered hormone to increase milk production by dairy cows. Known both as bovine growth hormone (bGH) and bovine somatotrophin (bST), the hormone would be injected into individual dairy cattle. Proponents of bST maintain that the growth hormone treatment offers dairy producers a safe method for increasing the efficiency of their operations, while opponents counter that the new technology poses risks to cows, humans and the dairy industry. The U.S. Food and Drug Administration is currently reviewing the safety and effectiveness of bST, and is expected to decide soon whether to permit the commercial use of the hormone. Experts at UC Davis reflect the spectrum of viewpoints on bST. For contrasting opinions, media should contact William Liebhardt, director of the UC Davis-based UC Sustainable Agriculture Research and Education Program, at (916) 752-2379 or Bennie Osburn, professor and associate dean for research at the UC Davis School of Veterinary Medicine, (916) 752-6865. For a complete list of sources on bST, media should contact Patricia Bailey, News Service, 752-9843.