Recently, a farmer asked what I thought of his batch of replacement heifer calves.

Initially they looked well; all had good coats and were grazing.

However, they did not appear close to the target weights that you would expect for the time of year.

We weighed a sample of the calves and they were six weeks behind target.

Clinically, there was nothing obviously wrong with the calves.

They had no evidence of scour and had good shiny coats.

We then looked at the history of the calves. As a group, they had previously suffered from pneumonia

This would rule out the two most common causes of ill thrift in dairy calves; parasites and mineral deficiencies. But appearances can be deceiving, so I took some blood and dung samples to check.

We then looked at the history of the calves. As a group, they had previously suffered from pneumonia.

It turned out there was a high level of worm eggs in the dung and copper levels were a little below normal.

Both of these issues were addressed with an oral dose and a copper bolus.

If the start of heifer breeding has to be delayed, this will have a serious effect on the profitability of those cows throughout their life

The most important thing was to manage weight gain, to maximise our chances of getting these heifer calves to their target weight for breeding next May.

If the start of heifer breeding has to be delayed, this will have a serious effect on the profitability of those cows throughout their life.

To get the calves back on track, we divided them by their current body weight into batches of 20 or less and will allocate them the best available grass along with meal for the grazing season.

They will then get silage and meal while housed and aim for as early a turnout as possible next spring, to get access to good-quality grass.

We will also need to address the calf pneumonia next year to prevent a recurrence.

We’ll start looking at that in January.

If your own farm is affected by similar issues, contact your vet and get it dealt with as early as possible.

Donal Lynch is the owner of Donal Lynch vets in Tullamore, Co Offaly, which is a member of XLVets Ireland.