Giraldo Giraldo, John Jairo2012-07-052012-07-0520081794-4449http://hdl.handle.net/10567/495In the dairy cattle the detection of cows in state of zeal has become one of the most important factors that diminish the reproductive efficiency. Although diverse complementary methods exist to improve the detection of those cows, the synchronization of ovulations and systematic insemination of all of the animals which state of zeal has not been detected, has become a viable and easy alternative of implementing with that from which a fertility rate from 35 to 40% can be obtained. In meat herds, artificial insemination has not been used as a tool for the genetic improvement, due to the difficulty in detecting the animals in zeal, and this is due to the geography of the pasture grounds and to the technical capacity of the personnel in charge of detecting animals in zeal, and of inseminating them. The implementation of programs for synchronizing ovulations and systematic insemination allows the elimination of the zeal detection process in breeding herds and concentrate the efforts on the artificial insemination task in a short time, allowing this task to be made by the veterinarian or a qualified technician and achieving a fertility rate from 40 to 50%. The combination of programs of ovulation resynchronizations with the precocious detection of empty animals, allows the systematic insemination of the empty animals without detecting zeal in the returns and to achieve a fertility rate from 55 to 75%, in two insemination rounds. In summary, the resynchronization ovulation and systematic insemination programs allow the elimination of the zeal detection in dairy cattle and beef cows, and also helps to maintain a level of viable fertility.esProstaglandinasCorporación Universitaria LasallistaHormona liberadora de gonadotropina (GNRH)Sincronización de celosProstaglandinas ovsynchInseminación artificialGanado lecheroGanado lechero - ReproducciónArticle