What can a pre-breeding scan tell you about your herd?

Calving may be in full swing on many dairy farms, but the breeding season is only a matter of weeks away. The importance of a successful breeding season can not be underestimated; it’s critical that farmers maximise the number of successful pregnancies achieved.

Speaking at a recent Interchem fertility seminar, Cathal O’Se – a vet with Riverview Veterinary Group in Co. Cork – discussed the role pre-breeding and targeted scanning plays when it comes to maximising the fertility of dairy herds.

“From the time I started in practice, I have always focused my attentions on fertility and scanning,” he explained.

Touching on what he looks out for during a pre-breeding scan, he explained that the ovaries and uterus take priority. When completed, he is able to offer the farmer an overview of the cow’s reproductive health.

O’Se said that vets are often called out to farms that have animals that have failed to show bulling.

“They’re animals that are going to fail to be inseminated and, ultimately, they’re not going to go in calf. There’s a cost associated with problem cows. There’s the cost of treatment, the loss of yield – a dirty cow isn’t going to produce as much – and there’s the indirect costs.

Finding problem cows by getting your vet out to do a whole-herd, pre-breeding scan is a profit-making opportunity. You’re going to find those problem cows and you’re going to fix them.

What are you looking for?

Touching on some of the common ailments witnessed during routine pre-breeding scans, O’Se said that metritis, endometris and pyometra infections can all be observed.

Metritis typically occurs within 21 days after calving, where as endometris – infection and inflamation of the uterine lining – is generally identified three weeks post-calving.

Pyometra is defined as an accumulation of pus in the uterus. It is generally found in “silent, dirty cows”, when a corpus luteum is present at the same time.

He added: “We are seeing a lot of dirty cows at the moment. It’s very much a balance between bacteria – which are going to be there in the post-calving uterus – and immunity.

“At the moment, immunity is definitely depressed in a lot of cattle across the herds we are dealing with for the simple reason that we’ve had a longer than expected housing period.

It’s been a long and tough winter and we have a lot of infection on-farm at present. Unfortunately, bacteria are actually tipping the balance and are winning the battle at the moment.

Other factors which tip the balance in favour of bacteria include: unhygienic calving environments; twinning; dystocia; and diet.

Along with identifying the possible presence of infection, a pre-breeding scan will also indicate if the cow is suffering from ovarian disorders, such as cycstic ovaries.

From the scan, he said, the vet will be able to tell how close the cow is to ovulating or if she’s anoestrus, sub-fertile or prepubescent (in the case of heifers).

Pre-breeding scanning can also identify scarring or mottling of the womb, he said.

“This is a feature that you will come across in herds with thins cows or cows suffering with lameness or mastitis. I have also come across the mottling effect in young heifers that have had respiratory disease previously.”