Now is the time to scan your cows

Kevin O’Hara, Education Officer, Teagasc Ballinrobe

Is scanning justified? This is a question facing many suckler and dairy farmers at this time of year. If you have bred cows or heifers in recent months, ask yourself the following - Are you certain that they are actually in calf or are some of them empty?  Why would you keep empty cows on your farm over the winter months, consuming expensive silage and in some situations using up N allowances on the farm.

So where do we start to put a plan in place for scanning?

Timing: 

It should be at least 30 days since the last cow in the herd could have been served. This is to ensure accuracy as it is difficult to pick up very early pregnancies. In many cases, especially, on suckler farms, farmers may need to scan 2 or 3 times in the year to get accurate calving dates for cows. These dates are hugely useful when it comes to managing cows over the winter.

Benefits of Scanning:

Firstly it will tell you what is and what is not in calf. This will allow you the opportunity to take out empty cows, wean their calves that bit earlier and have them finished with some supplementation off grass before slaughter, or in a dairy situation these cows may be dried earlier and culled in the backend to allow more grass for productive milkers. This will save money, time, shed and slurry space and organic N allowances.

Most scanners will be able to give you a good estimate of the number of weeks that each cow has gone in calf. You can use this information to predict the cows due date which will influence how she is fed and when she is to be vaccinated (if you use a scour vaccine). It will also allow you to predict the peak calving period so that extra help can be planned or when you may need to take time off work. 

By identifying when cows are due to calf they can be batched nearer calving time so that they are easier move to calving boxes and calving facilities. Late calving cows can be restricted on feed to stop them getting over fat. Thinner cows, in-calf heifers or cows carrying twins can be taken out and given additional feed if necessary

Provided cows haven't gone over 12 -14 weeks in calf you may well be able to pick up if there are any cows carrying twins which will alert you to watch the condition of these cows in the run up to calving. It will also have you primed for what to expect at calving. Some scanners may even sex the embryos which can be useful to know in a difficult calving situation.

If the scanning reveals more than 5% of your cows are empty then this may signify that there is a fertility problem in your herd. Maybe it was a bull issue or perhaps a mineral deficiency or a disease problem.  Whatever the cause, it should prompt you into investigating the issue further.

Scanning Costs:

Scanning costs can vary but generally cost approx. €3 per cow plus a call out charge (€20 - €50). Rates will vary and may be dependent on the number of animals being scanned and the time it takes to scan the herd of cows but it is money well spent.