AI is used far less commonly in beef herds compared to the dairy industry. Reasons for this include perceived costs compared to a stock bull, difficulty with heat detection whilst out at grass and lack of handling facilities to get cows in to serve them.
However there are major benefits, which include increased genetic gain, breeding heifers specifically for replacements (good maternal traits rather than terminal sire traits) and improved calving ease.
There are two ways to overcome the heat detection issue:
- Use a teaser bull: A young bull (ideally <12 months) has an operation performed to remove a portion of the epididymis (the storage and transport tube for sperm). He still has his testicles so will show mounting behaviour; a chin ball marker is then used to identify cows that he has mounted.
- Synchronising groups of cattle for fixed time AI (FTAI): Progesterone device protocols (e.g. CIDR-synch) are the most successful in beef cows and heifers. This usually involves two visits from us followed by a pre-booked visit from the AI technician and we usually achieve >50% pregnancy rate to the first service.
We currently have a special fixed price of £25 per cow (plus the visit charge) which includes the cost of the drugs. Please speak to one of our vets for the most appropriate protocol for your farm.
Practical Tips For Top AI Results
We are quick to blame cows for poor fertility rates but we don’t often review AI techniques. Correct timing of insemination is important; the am/pm rule is still helpful but it is old advice, first demonstrated in 1943! Only 50% of Holstein cows will show standing to be mounted (STBM) therefore it is important to optimise heat detection, insemination technique and semen quality. 94% of ovulations are 16–40 hours after onset of heat; the recommendation for sexed semen is to AI 14–20 hours after observed heat.
- Check your flask! Shouldn’t lose >1cm liquid nitrogen per week
- Thawing technique: 35–37°C for minimum 45 seconds
- Insert straw into a pre-warmed gun
- AI cow within 10 minutes; thaw one straw at a time
- Semen should be placed in the body of the uterus not in the horns
