The first stilbestrol feeding experiment with beef cattle was conducted 10 years ago (1953) at Iowa State University. Since then nearly every state university, many foreign countries and several feed manufacturers have conducted stilbestrol research. In these studies essentially all cattle feeding conditions have been explored. Information from more than 100 cattle experiments is used in this review to answer many of the questions posed at different times by different individuals regarding stilbestrol feeding.

Some questions were answered in 1954 in Iowa State Pamphlet 215, "Questions and Answers About Adding Stilbestrol to Feeds for Growing and Fattening Beef Cattle." Since then stilbestrol usage has spread throughout the cattle feeding industry. This use of stilbestrol feeds has continued. More questions are being asked. The more recent questions reflect the impact of stilbestrol use upon all segments of the beef industry.

Stilbestrol is incorporated into cattle feeds for purposes of increasing liveweight gains and lowering the feed cost of gains. The incorporation process consists of mixing specially compounded stilbestrol premixes into cattle supplemental feeds. Feed manufacturers produce these supplemental feeds in accordance with state and federal regulations. Each bag or batch of supplemental feed carries a label stating the amount of stilbestrol in the supplement and directions for use.