Last spring, I had a call from a suckler farmer who was concerned that more of his cows were repeating than normal. He calves about 80 cows from September until February.

The history was that his Limousin bull was getting old and the farmer thought he was slowing down, so he had bought a new, young Limousin bull well in time for this year’s breeding season. The two bulls were running together with the cows.

We agreed that the first thing we should do was to scan some of the earlier calving cows to see if they had gone back in calf. As it was still in the breeding season, it was hard to interpret the scanning results, as any of the cows not showing in calf could have been served in the four weeks beforehand.

However, there were 32 cows not yet showing in calf and those that were in calf were later and more spread out than would be expected.

There are many reasons for reduced fertility, but as the cows were in good health and body condition and with the pregnancy pattern, we decided that the first thing we would investigate was the bull fertility.

XL Vets has put a lot of effort into training and equipping members so that they can do this in their own practices.

On this farm, the semen sample from the young bull contained a very low sperm count and about half of the sperm were abnormal.

This case highlights the value of testing a new bull before he starts working or buying a bull that has been properly certified as having been tested. You also need to keep an eye on your cows, as a bull that works well one year can, for a variety of reasons, become infertile and not work the next year.

Our farmer still had a month left in the breeding season and bought a new bull that he tested first. Unfortunately, he ended up with 10 cows not in calf when he finally took out the bulls.

Shane McGuckin is a partner in The Vet Hospital, a five-person mixed practice in Gorey. The Vet Hospital, Gorey, is part of XLVets. XLVets is a group of progressive practices working together to achieve a better future for agriculture and veterinary in Ireland. For further information, go to www.xlvets.ie.