Why Dairy Farmers Should Consider Increasing the Use of Sexed Semen

There’s a compelling case for dairy farmers to increase the use of sexed semen in their herds, especially in light of recent trends in replacement rates and the number of dairy females born this year.

As of April 1st, the number of calves registered from the dairy herd is over 16,000 lower than at the same time last year—a decline of around 1.4% (see Table 1). More concerning is the drop in dairy female calf registrations, which are down by over 38,000 compared to the same period in 2024. That’s a reduction of more than 11.5%, which is expected to result in fewer replacement heifers available in 2027.

Table 1. Birth Registration Statistics

Additionally, the number of first-calved heifers recorded by April 1st is about 25,000 fewer than in 2024, representing a 9% drop. This combination (i.e. a sharp decline in both dairy female calves and first-calved heifers), suggests that the market for dairy heifers is likely to be strong over the next few years.

Given that pregnancy rates with sexed semen are only about 10% lower than with conventional semen, the impact on herd fertility is minimal. Plus, having heifer calves born together during the first round of AI simplifies rearing and reduces costs.

Although dairy bull calves are currently making good prices, dairy farmers should be cautious about focusing on these short-term gains. The long-term benefits of producing enough dairy heifer calves early in the calving season far outweigh the value of male calves.

As outlined in our recent Dairy Breeding Guidelines, farmers are strongly encouraged to consider the use of sexed semen. To maximise results, follow these key recommendations:

  • Use a minimum of two high-EBI sexed semen straws for each replacement dairy female required.
  • Prioritise insemination during the first three weeks of the breeding season to increase the chances of success.
  • Target the most suitable animals, including maiden heifers, younger cows (in their 1st to 4th lactation), and those that calved early (January/February).
  • Ensure optimal timing for AI—ideally between 14 to 20 hours after the onset of standing heat.