Spring turnout is the highpoint of the year for many Welsh dairy farms but the associated labour saving and feed cost benefits are often diminished by an annual spike in somatic cell counts.

When 8% of the herd – one cow in 12 – has a high SCC during the first month of calving, from day four to 28, it indicates a problem, says vet Dr Sotirios Karvountzis, of Llandeilo-based Mendip Vets.

Farmers invest money in housing cows in clean, well-ventilated and temperature-controlled conditions in the winter, in contrast to the situation at turnout when control over their environment is relinquished, Dr Karvountzis points out.

“Although grass is fairly clean it is not dry, we have no control over moisture levels and we cannot disinfect,’’ he says.

“Cows will tend to return to the same area of the field to lay down, where they may or may not have leaked milk, so that area could have some level of infection.’’

It can take 6-12 hours for the teat to seal after milking, a period that has extended greatly with changing genetics.

“Twenty years ago it was thought that it took 30 minutes for the teat to seal but as yields have gone up it can be anything from 6-12 hours depending on teat conformation and yield and that exposes the udder to possible infection for a very long time,’’ says Dr Karvountzis.

To prevent the annual elevation in cell counts, he advises avoiding mob grazing when cows are at maximum yield.

Mob grazing reduces the space available to each cow and increases the chances of them lying on a patch of grass that might have been contaminated by a leakage of milk.

Although there are many good reasons for mob grazing, the potential risk it poses to udder health at this time mustn’t be underestimated so it is sensible to avoid this system of grazing when yields are high, says Dr Karvountzis

Using an iodine-based dip before and after milking is important too, he adds.

“Dips and sprays each have their benefits but at this time of the year I would advocate using a dip pre- and post-milking because, provided it is used correctly, it covers the entire teat from the base to the tip of every teat, every quarter of every cow.’’

Dipping is more time consuming but it gives a head start on protecting the teat from pathogens until the end seals.

Don’t overlook the important role of trace elements.

“Take the advice of your first opinion vet on correcting any trace element deficiencies that may be contributing to high cell counts,’’ says Dr Karvountzis.

“Selenium, vitamin E, cobalt, copper and, to a lesser extent iodine and zinc, even in small amounts can improve the immunity of cows.

  • Want to make sure all the latest farming news from Wales is delivered straight to your door? Subscribe to the print edition of Wales Farmer on 0800 052 0198.

“There are no independent published studies on the correct amounts needed but we know that they help the cow to fight off the infections that result in high SCCs.’’

Look at what is in the cow diet – while trace elements are important, so too is nutrition generally.

Many people ignore the role of ammino acids, largely because they are very expensive at around £1,000 a tonne, Dr Karvountzis suggests. “A cow will need 5-50g a day, depending on her specific requirement.’’

Ensure there is sufficient high quality protein in the diet to provide this, especially during early lactation.

Automatic cluster removal (ACR) should be set correctly to avoid over-milking.

Over-milking will result in ‘calluses’ forming on the teat end which prevent it from closing, taking away a massive barrier to infection.

Most parlours are set to remove clusters when there is 200ml of milk left – that is just 50ml in each quarter which Dr Karvountzis describes as “incredibly low’’.

“The minimum I would recommend is 800ml – 200ml in each quarter,’’ he says.

It is important to ensure a minimal gap between when the ACR starts pulling the cluster away from the teats and the vacuum being cut off.