With winter breeding right around the corner, farmers are busy preparing and picking their bull teams to ensure they have a successful 2026.

As well as this, a lot of farmers will be weighing up their options in terms of using artificial insemination (AI) and sexed semen.

Sexed semen has soared in popularity over the last number of years, with the adaption of technology such as heat detection collars allowing the insemination method to boost the dairy herds genetic gain.

Sexed semen also has the ability to improve farm finances, while reducing the volume of low value dairy bull calves.

However, the method takes that bit more work and precession, so doing your homework first is crucial to ensure you are aware of the most cost-effective strategies to follow when integrating sexed semen into the dairy herd.

Sexed semen

Sexed semen is known to have a lower conception rate to conventional, which can turn some farmers off using it.

However, on-farm data has shown a year-on-year improvement in conception rates when using sexed semen, which is a welcome development considering sexed straws now cost up to €50/straw.

This improvement is however largely due to farmers carefully following the correct protocols, learning from experience, and adapting to advancing technology.

One problem with sexed semen is some farmers have grown overly reliant on the method.

This can result in problems in achieving their target amount of replacements, which is evident through the 350,000 sexed semen straws used this year, and the dwindling dairy heifer numbers.

When using sexed semen, your breeding programme for replacements will be relatively the same as it would under conventional.

You will still be choosing a large enough team of bulls that have the ability to improve the areas of the herd in which you want to improve.

You will however need to be breeding within the top 50% of the herd to strive for genetic gain, typically breeding cows should have;

Parity one to four;
Over 50 days in milk on day of AI;
Body condition score (BCS) of over three;
Ensure they are cycling regularly;
Ensure they have no postpartum disorders or uterine disease.

Management

Handling of sexed semen straws is one of the main areas that can result in poor conception rates.

Once your straws are thawed, they will rapidly loose their success rate, so thawing a maximum of two at a time and using them within minutes is highly recommended.

These straws need to be thawed at a temperature of 35-37℃ for a duration of 45 seconds.

From here, load them into a a pre-warmed AI gun and deposit the semen in the uterine body, making sure the insemination is completed within five minutes.

Mistimed breeding is another major reason sexed semen can fail in terms of conception, as sexed semen has a much narrower breeding window than conventional AI does.

Ideally, sexed semen should be used within the first 10 days of breeding, or at a maximum within the first three weeks of the breeding season.

Cows should be AI'd with sexed semen 14-20 hours after the onset of heat, for example;

Onset of heat between 1:00a.m and 7:00a.m: AI at 9:00p.m. that night;
Onset of heat between 1:00p.m. and 7:00p.m.: AI at 9:00a.m. next morning;
Onset of heat between 4:00p.m. and 10:00p.m.: AI at 12 noon the next day;
Onset of heat between 7:00p.m. and 1:00a.m: AI at 3:00p.m. the next day;
Onset of heat between 10:00p.m. and 4:00a.m: AI at 6:00p.m. the next day;

Breeding within this window can be hard to achieve if the herd is not equipped with heat detection technology, such as collars.

Some farmers try to overcome this challenge through the use of fixed time AI, however this can be a costly system.

By serving the herd twice a day with the correct management practices for sexed semen, your success rates should be respectable.