As we approach the breeding season, there has been a lot of interest in using sexed semen.
In this video, Dr Stephen Butler, Teagasc Moorepark gives an overview of how to maximise the success of using sexed semen in this year’s breeding season.
“First the bulls. Pick the highest EBI bulls that are available, these are going to give you long-term genetic gain in your herd. Secondly, use a team of at least 5 bulls. Some bulls a big reduction in fertility after sorting, but we have no way of knowing in advance who those bulls are.”
“In terms of the females, heifers are the first choice because these are the highest fertility animals in the herd and generally the highest EBI animals in the herd. Heifers should have reached the target live weight and be in good body condition. You should know that these animals are cycling before the breeding season commences.”
“You’ll also need to use sexed semen on cows, and you should target the best fertility cows in the herd.”
Rules of thumb for selecting cows:
Cows should be in parity 1 to 4;
At least at 50 days at milk on the day of A.I;
Have a body condition score of 3 or more;
Cycling regularly and free of postpartum disorders and uterine disease.
When should we use sexed semen?
First 3 weeks of the breeding season;
Within the first 10 days, if possible.
Timing of AI
14 to 20 hours after onset of heat.
Fixed time AI
Costly, but mitigates risk;
Facilitates targeted usage of sexed semen on mating start date.
Straw handling on day of AI
Organise sexed straws into one goblet;
Thaw 2 sexed semen straws at a time;
Thaw straws at 35 to 37 degrees for 45 seconds;
Load straws into pre-warmed AI guns;
Deposit semen in the uterine body;
Complete insemination within 5 minutes.
Video source: Teagasc YouTube