Monitoring bull fertility during the breeding season
While most of the work听arguably has听already been done to set up the herd for a successful breeding season in terms of nutrition, vaccinations and pre breeding checks, it is important to听monitor听bull performance during the breeding period.听听
For herds calving in March and April stock bulls will only have been out with cows for a couple of weeks, and irrespective of the age of the bull, it is important to monitor bull performance to ensure that cows are holding to service, to reduce the risk of experiencing losses from bull infertility.听听
It is advised to听regularly听observe听bulls out with cows to allow for any concerns to be picked up quickly before these then have an impact on herd fertility and productivity. This is now more important given the Scottish Suckler Beef Support Scheme (SSBSS)听requirement for a 410-day calving interval.听听
Record when you see a cow mated and watch for听her repeating (bulling) 21 days later.听A听significant number听of cows returning to service could suggest bull fertility or libido issues.听It is important to remember that although a bull may have undergone a pre-breeding examination and fertility test prior to being听turned out with cows听he听can under form if听he听has听picked up an infection, became lame, or has听damaged听his听penis.听There is a lot听that听can go wrong with a bull, affecting his ability to serve cows. Therefore,听monitoring听groups for returns is crucial to ensure issues are听identified听as soon as possible, before herd fertility is compromised.听听
For those herds rotating bulls between groups during the breeding season, it is even more important to continue to听monitor听bulling activity, to avoid fertility loss from bull subfertility.听A sub-fertile bull will get some animals pregnant, but this will take longer and several services, making the problem harder to听identify, especially in systems where bulls are rotated during mating.听
If you have concerns, seek advice from your farm vet as soon as possible, as waiting until pregnancy scanning is too late to resolve problems.听听
Sarah Balfour, Beef Consultant,听Sarah.Balfour@sac.co.uk
Posted by SAC Consulting on 16/06/2026
