During a four-week period of artificial insemination (AI), 35 of the 38 breeding heifers were mated.

Then, in mid-May, the Salers stock bull was turned out to mop up for around six weeks which would have brought the breeding period to a close by the end of June.

However, early this week, Tullamore Farm manager Shaun Diver, noticed a couple of heifers repeating that he had seen served three weeks earlier.

As a precaution, it was decided to fertility test the bull.

Unfortunately, the result was that the bull was completely infertile. It is worth pointing out that the bull had been tested prior to the onset of the breeding season and scored 94 out of 100 for morphology. The problem, therefore, had to have happened since the onset of breeding.

The cause

The only reason that Shaun can attribute to the infertility is that the bull did go slightly lame about a fortnight ago for a couple of days. This was not a major hurt and did not require any veterinary intervention.

However, it goes to show how minor knocks can have a negative effect on bull fertility.

Anything that causes the body temperature of the animal to increase such as an infection, can damage the sperm in the testicles.

It can take up to six weeks for the animal to become fertile once again post-infection.

Replacement bull

Shaun was quick to get a replacement bull on the same day that the fertility test was done so as to minimise the chance of any further missed heats.

The replacement bull is a four-year-old Salers bull and comes from the same breeder as the previous stock bull.

While breeding was due to finish in about two weeks’ time, Shaun is now planning to extend that by another two to three weeks

In all likelihood, the stock bull will become fertile again after a period of recovery.

However, Shaun plans to cull the bull later this year if the new bull performs well over the next few weeks.

Prolonged breeding season

While breeding was due to finish in about two weeks’ time, Shaun is now planning to extend that by another two to three weeks to maximise the number of heifers in calf.

It will, undoubtedly leave some later-calving heifers but numbers should hopefully be low as there has not been too much bulling activity over the last few weeks.

Fortunately, thanks to Shaun keeping a close eye on bulling dates, this was picked up as early as possible.

It could have gone unnoticed and resulted in a disappointing scanning day.

It really goes to show the importance of marking bulling dates in your phone or diary and keeping a close eye on stock bulls.

If in any doubt, check for fertility issues as soon as you think there is a problem.