The importance of bull pre breeding examinations
We understand that ensuring your cows are in calf is vital to ensure business can continue successfully.
Did you know that 1 in 4 bulls in the UK has sub-normal fertility? This could be due to small scrotal circumference, poor semen quality (motility or morphology) or poor serving ability.
The definition of a ‘fertile’ bull is one that would be expected to get 60%, within 3 weeks, and 90%, within 9 weeks, of 50 normal cycling cows pregnant.
It takes approximately 60 days for new sperm cells to be produced, so an incident or injury involving your bull could affect his mating abilities. As such, a full history of the last 60 – 71 days is useful when assessing fertility.
Fertility is also affected by age. Studies have shown that a higher percentage of bulls fail the test when conducted <15 months of age (mounting behaviour or scrotal circumference is not a finite indicator of sexual maturity), also that once bulls are over 4 years old the percentage of bulls that pass the pre breeding exam reduces significantly each year.
So, how can we help to make this happen?
We can perform pre-breeding examinations 8-10 weeks before a bull is put to work, to help identify underperforming, sub-fertile bulls. This examination can also help to estimate how many cows may be successfully served, giving you a better idea of what numbers to run the bull with.
What does the process involve?
Electro-ejaculation (EEJ) is the standard method of semen collection. This procedure is carried out by a specially trained veterinary surgeon who has undertaken additional training to gain a certificate in the process. It usually takes around 60 minutes and is a safe procedure if an appropriate crush is available.
The vet will conduct a physical inspection of the bull, including a general health check as well as checking scrotal circumference, examination of the penis, prepuce and sheath, plus palpate the testicles to ensure all is up to standard. Where appropriate, breed standards, agreed with the breed societies, are used.
Once the semen sample has been collected it will be tested on-site (a power source is required) for motility – the capability of sperm movement. This will allow a general idea of how the bull will perform. An additional sample can be carried out within the same pre-breeding examination if the first sample is showing suboptimal results.
The remainder of the tests (such as analysing morphology – the size and shape of the sperm) will be done at our lab where we offer a quick turnaround of confirmation of results.
A certificate will then be issued based on the physical examination and sperm examination performed on that day. If required, a 3rd stage can be added to assess mating ability, but this is usually only done in special cases.
What facilities are needed?
To safely perform a bull pre breeding examination we ask that all clients have:
- A safe, working crush of a suitable size for you bull. The bull needs to be able to move gently side to side during the test
- Access to mains electricity to allow us to set up our on-farm laboratory (this needs to be undercover)
- Sufficient staffing to safely move the bull into the crush
- Space to watch the bull walk into the crush
Additional benefits of carrying out a bull pre breeding examination?
It may be that you’re looking to move a bull on and wish to prove its breeding expectations to increase value. We can carry out a pre-sale PBE so the bull can be sold with the certificate confirming fertility probability.