In the relatively recent past different devices were developed to monitor estrus. Examples are those that record increased cow activity alone (pedometers), or a combination of the latter with a reduction in intake and rumen motility.
Traditionally, the methods used to detect estrus in dairy cows include visual observation, tail painting, tail chalking, rump-based pressure and scratch-off patches. In high-producing cows, the duration and intensity of estrus behavior is considerably lower than that in dairy cows of a few decades ago.
Using sex-sorted semen has become a common reproductive practice in the dairy industry. However, it has been shown that using sex-sorted semen reduces fertility which can be caused by the sorting process of the sperm altering the fertilizing capacity and viability of spermatozoa and/or the lower number of spermatozoa per straw.