Service time


Observe heifers / cows at least three times daily for at least 15 minutes especially in between milking and feeding times.

Many cows may show very short periods of standing heat. Evening heat detection is essential. Record standing heats accurately to verify regular oestrus cycle length. Cows or heifers with abnormal cycle length will be less fertile.

Other signs of oestrus e.g. mounting, chin resting, vocalisation can be less reliable signs of heat. Less valuable semen can be used to serve these animals, even using two inseminations 24 hours apart. This is not advised for sexed semen.
Heat detection aids are very important e.g. kamars, tailpaint or MooMonitor+.


During this period you should ensure stress free handling to ensure best results, service should be carried out 14-20 hours after the onset of standing oestrus. Heat synchronisation programmes should only be used in conjunction with good heat detection and not based on fixed time AI.

Heifers and cows should be restrained so that they cannot move forwards and backwards or sideways. A proper service area and crush are essential. Quietly move animals to the service crush in pairs or small groups. Animals on their own become frightened and stressed.


Because sexed semen is a premium product, only inseminate heifers that have been identified in standing oestrus. Heifers do have a small cervix which can make it difficult to pass the AI gun through.

It is important that semen deposition is in the uterine body and NOT in the cervix or either of the horns.

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