Conception rates in general last year seemed to be poor with colder weather and challenging conditions in spring, and sexed semen conception rates in particular took a hit.

Although conception rates were poor last year due to the impact of the weather on grass growth and feed availability, rates with sexed semen have improved over the years. However, it might still be a product that needs further refining.

The usage of sexed semen has increased by 50% in only two years. It is one of the key measures dairy farmers can use to increase their genetic gain by intensively selecting which cows are to be the dams of future replacements.

An Irish Cattle and Breeding Federation (ICBF) analysis of field data over five years shows that the relative performance of sexed semen compared to conventional semen is 92%.

However, sexed semen will not suit every herd in the country. Many herds may have poor fertility or a cohort of older cows that would not suit putting a sexed straw to.

In order to achieve good conception rates with sexed semen, it has to be inseminated into a suitable cow at the right time of their heat.

Sexed semen reduces the reliance on conventional dairy semen, which also allows herds to increase the usage of high beef merit bulls on dairy females, leading to higher commercial beef value (CBV) on the ground.

This is beneficial for both the dairy and beef farmer as it increases profits for the dairy farmer while the beef farmer is left with a calf with a reduced age to slaughter, and less inputs in its lifetime.

To ensure successful conception rates with the product, the correct females need to be selected in the herd, typically cows or heifers with their third or fourth lactation to ensure genetic gain and that the straw holds.

Using sexed semen on heifers will lead to breeding replacements from your heifers, leaving you with the quickest rate of genetic gain.

Heifers are in a lot of ways a 'clean slate' in terms of health and calving related issues and they are the most fertile in the herd according to the ICBF.

When selecting cows for sexed semen, ensure that they are calved at least 60 days by the start of the breeding season and have a body condition score of 3 or over.

Make sure these cows have had no health issues in the past number of years from difficult calvings, metabolic issues, or mastitis, and are free from any postpartum disorders or uterine disease.

It is also crucial to ensure that the cows selected have a record of always going in calf after one serve and have a calving interval close to 365 days.

These cows should be identified as regularly cycling, as well through pre-breeding checks in the lead-up to the mating start date.

Also make sure that the cows you are selecting are of a high genetic merit and go towards what you are aiming to breed.

The selection of cows for breeding is just as important as selecting bulls, as the genetic potential of an animal initially comes from the average of both sire and dam figures.

The timing of insemination is paramount to the successful conception of sexed semen and it should ideally be used in the first three weeks of the breeding season or within the first 10 days, if possible.

Timing of artificial insemination (AI) is more critical for sexed semen compared to conventional and, for maximum success, AI with sexed semen should take place 14-20 hours after the onset of heat.

The problem with this is that, for farmers without collars or heat detection devices, it can be very difficult to pin-point the first onset of heat.

When farmers AI twice a day, most dams will be at the optimum time for sexed semen either in the morning or evening.

The handling of sexed semen straws is crucial to its success, as once the straws are thawed, they have to be used in a matter of minutes.

The recommendation is to organise sexed straws into one goblet for easy access and to only thaw two straws at a time.

Straws should be thawed at 35-37℃ for 45 seconds and then loaded into a pre-warmed AI gun, which should be kept warm for the duration of AI.

Deposit the semen in the uterine body and make sure the inseminations are completed within five minutes to maximise the performance of sexed semen usage.