Improvement on the efficiency of doses per conception by using a semen extender in timed artificial insemination

•Extender in timed artificial insemination reduced the number of doses per conception.•Extender not influencing in vitro embryo production and fertilization rate.•The total and progressive motility post-thawing did not differ between the groups.•Semen straws of a single bull were evaluated both groups in all the techniques.•Extender allowed for the more efficient use of semen reducing the cost per pregnancy.