At ReproVet Ireland, we offer Dairy Cow Synchronisation and Fixed-Time Insemination services to optimize your herd’s reproductive efficiency. Implementing synchronisation protocols, especially when using sexed semen, can enhance conception rates, improve your 6 week calving rate, and schedule your breeding workload. Modern fixed-time insemination synchronisation programs, eliminate the need for heat detection and allow a high number of early-season inseminations, increasing your submission rate.
Recent work published by Teagasc has emphasised the importance of timing of artificial insemination (AI) when using sexed semen, with studies indicating that inseminating cows 22 hours after the second GnRH injection yields better results.
Recommended Dairy Cow Synchronisation Protocol
| Day | Protocol Step |
|---|---|
| 0 | Scan cow, insert Progesterone (CIDR/PRID) device and administer GnRH injection |
| 7 | Administer Prostaglandin (PGF2α) injection |
| 8 | Remove CIDR/PRID device and administer second Prostaglandin (PGF2α) |
| 9 | Administer GnRH injection 36 hours after PGF2α |
| 10 | Perform fixed-time AI 16-22 hours after the second GnRH injection |
ReproVet’s top tips for selecting cows for sexed semen:
Selecting the appropriate cows for sexed semen in an Irish spring-calving, grass-based dairy herd is crucial for maximising conception rates:
- Target Young Cows:
- Focus on cows in their first to fourth lactation, that are calved more than 50 days, with a BCS of ≥3.00, and are cycling regularly. Ensure they are free from any postpartum disorders (lameness, displaced abomasum, rumen acidosis, milk fever, ketosis, retained foetal membranes) and uterine diseases (metritis, endometritis, cystic ovarian disease, irregular heats).First calvers are not always suitable for sexed semen – they are often the animals under most stress in a herd.
- Prioritise High EBI, fertile cows:
- Select cows with a high Economic Breeding Index (EBI) to enhance genetic gain. Using sexed semen on these animals ensures more rapid genetic gain.
- Use a Team of High-EBI Bulls:
- Reduce the risks associated with individual bull fertility, by using sexed semen from a diverse team of high-EBI bulls (preferably five or more. This enhances genetic diversity and reduces reliance on the fertility performance of a single sire.