Oklahoma State University
This fact sheet discusses heat detection aids for the best outcome when using artificial insemination for dairy and beef cattle. The most limiting factor in artificial insemination programs is the proper detection of cows or heifers in estrus. Estrus, or "heat," is that period of time that occurs every 18 to 24 days in sexually mature, non-pregnant female cattle when they are receptive to mounting activity by bulls or other cows. In beef cattle or dairy operations where artificial insemination is the means of breeding the females, the herdsman must recognize and interpret a cow's heat signals.