Sexed semen in the Irish dairy industry
With twice as much sexed semen available for the 2023 breeding season as in 2022, highlighting the rapid increase in uptake on dairy farms, Stephen Butler, Principal Research Officer in Reproductive Physiology, highlights some of the research work ongoing in sexed semen in Teagasc Moorepark.
The use of sexed semen allows the calf sex to be determined with ~90% reliability. This allows dairy farmers to generate the required number of replacement heifers for their herd, while reducing the number of male dairy calves.
Genetic gain in the dairy herd can be accelerated by selecting heifers and cows in the top half of the herd for EBI to be eligible for insemination with sexed semen at the start of the breeding season. All remaining dams should be bred using high DBI beef semen, producing a saleable beef-cross calf.
There are obvious management benefits to be gained from having all replacement heifers born in the first few weeks of the calving season, whether they are being reared at home or being sent to a contract rearer. All subsequent births will be beef-cross calves.
One consequence of using sexed semen on all the highest EBI dams will be a marked reduction in the number of male dairy calves derived from high EBI dams. Presently, a very small number of these high-EBI male dairy calves are selected to become future AI bulls. The ‘loss’ of these rare but genetically superior calves could reduce long-term genetic gain in the national herd.
Research in Teagasc Moorepark is examining the potential role of in vitro embryo production to accelerate genetic gain in the face of the declining number of male dairy calves. The procedure involves harvesting eggs from elite genetic merit donors, fertilising these eggs in a lab using semen from elite genetic merit sires, and allowing the resulting embryo to develop for seven days.
The embryos are transferred into a recipient heifer or cow that has been synchronised to be on day seven of the cycle. The potential to produce the embryos using sex-sorted semen is also being investigated. With these approaches, it is possible for a single dam to produce up to 20 calves per year, and the sex of these calves can be predetermined.
Moorepark Dairy Open Day
The results of the latest research will be presented at the Teagasc Moorepark Dairy Open Day. In the below video, Dr. Stephen Moore, Teagasc Research Officer, provides an insight into what to expect at the Breeding and Reproduction Village at Moorepark '23, which takes place on Tuesday, July 4th. A major focus will be on how to better integrate the dairy and beef industries.
Along with the results of the research outlined above, an update on the EBI developments to improve sustainability, the benefits and opportunities of sexed semen – along with key beef breeding tools – will be presented.
The Breeding and Reproduction Village at the event will include:
- EBI (Carbon, Beef, Health) and the Next Generation Herd;
- DairyBeef500, Dairy-Beef Trilogy: DBI, Sire Advice and CBV;
- Optimising sexed semen use.
This article was adapted from the May/June issue of Today's Farm.