RESUMO
The main objective of the implementation of Artificial Insemination (AI) in cattle is to produce a sustained genetic progress in the herd. Although AI is an old reproductive biotechnology, its widespread implementation is very recent and is mainly due to the use of protocols that allows the AI without heat detection, commonly called fixedtime artificial insemination (FTAI). The development of FTAI protocols also allowed the application of AI in larger, extensively managed, herds and especially in suckled cows ins tead of just reducing the breeding programs to the heifers. FTAI treatments are widely used in South America, with about 2,500,000 cows inseminated in the last season in Argentina and about 6,500,000 in Brazil. This manuscript aims to present and describe several treatments available and some of the factors that may affect pregnancy rates.