Culling of cattle in a beef operation usually implies removing those that cannot meet or maintain performance and economic criteria for the herd. Other reasons may include physical or temperament problems in animals, as well as judicious culling during periods of environmental hardship or economic necessity. The judicious removal of nonperforming females is also important to maintain or improve herd fertility. However, the assumption that cull cows are necessarily infertile may not always be correct; recent surveys indicate that ~43% of cull cows in the USA are pregnant at the time of culling. All “open” females are not necessarily infertile. Identification of appropriate candidates for culling is critical and should be an important component of pregnancy testing.