Back in June, the Agriculture and Horticulture Development Board (AHDB) reported the results of a survey of cattle breeding companies, which suggests UK dairy farmers are world-leading when it comes to the uptake of sexed semen.

In the 12 months to April 2024, a total of 86% of all dairy semen was sexed, compared to 76% in the previous 12 months.

There is no doubt the technology has helped deliver massive efficiency gains, allowing farmers to breed replacements from their most productive cows. It has also helped minimise the number of low-value, dairy-bred males.

But the switch to sexed semen has brought some challenges, simply by the fact it has led to a surplus of replacement dairy heifers. It has been easy for farms to expand in numbers. Given extremely tight land availability in NI, stocking rates go up, which inevitably means more cows must be kept inside. Farmers are being pushed into higher cost-production systems and working even longer hours for minimal financial gain.

Reassess

Perhaps then there is a need to reassess what proportion of the herd should actually be bred with sexed semen and whether farmers are over-compensating for lower conception rates. In that context, analysis of data by the Irish Cattle Breeding Federation is relevant – previous studies in 2013, 2018 and 2019 showed pregnancy rate for sexed semen was 84% of that from conventional semen.

However, the latest work in 2023 indicates a relative pregnancy rate of 92%. When good practice is observed, there is no need to breed half the herd to sexed semen.

TB

There is another factor leading to more intensive systems of production, and that is the record rate of bovine TB on farms in NI. As well as having to retain replacement stock, there is that fear it could turn into a major outbreak, resulting in a significant proportion of the herd being lost.

As a result, voluntary culling of older stock is often not as robust as it should be.