By Debbie James

A Welsh dairy farm, which put measures in place to prevent rumen fluke infecting its herd after mud snails hosting the parasite were detected on the holding, has been rewarded with an uplift in milk production.

Rumen fluke was once regarded as rare in the UK but is now an emerging problem in some regions, including west Wales where Liam and Annie James farm.

They were involved in a study led by the Institute of Biological, Environmental and Rural Sciences (IBERS) at Aberystwyth University in conjunction with Farming Connect which surveyed potential mud snail habitats.

Both rumen and liver fluke were detected at Hafod Farm near Llandysul, with levels of rumen fluke the highest recorded on the survey farms by the research team.

Six snail habitats were identified at this 120-acre dairy farm, which the James’ farm in partnership with Mrs James’ father, Clive Lott.

Snails in three of these habitats were infected with liver fluke and rumen fluke infection was detected in snails in two of the sites, posing a significant risk of infection to livestock grazing the surrounding areas.

The James family are in their fifth year of farming at Hafod and, although they are aware that poor drainage has resulted in some very wet areas, they were surprised by the results of the sampling.

“We’d had reports from the abattoir of liver fluke in a couple of cull cows but we were completely unaware that we had rumen fluke in the herd,’’ says Mr James.

Liver fluke and juvenile stages of rumen fluke can affect milk yield but visually it can be difficult to detect if a cow is infected.

There is often no clinical significance of rumen fluke, but if calves grazing waterlogged pasture show signs of severe diarrhoea, rumen fluke diagnosis should be considered.

As a result of the findings, a flukicide that covers both rumen and liver fluke is now administered in the dry period at Hafod Farm instead of a liver fluke-only product.

Areas where the snail habitats were detected have also been fenced off – initially with temporary fencing but this is being replaced with permanent fencing - and a drainage programme is underway.

Payback from the investment is coming from higher milk yields, said Mrs James.

“We have identified a rise in milk yield of around 1kg/cow/day which I think we can certainly in part link to the increase in health due to the targeted treatment of rumen fluke on the farm as not much else has changed in terms of farming practice,’’ she said.

The spring-calving herd of 140 Friesians and Norwegian Red crosses is yielding an annual average of 5,000 litres at 3.50 per cent protein and 4.15 per cent butterfat, with milk sold to Arla.

The habitats at Hafod Farm were identified using a new technique developed at Aberystwyth University which detects the DNA of mud snails infected with fluke.

Dr Rhys Jones, of Aberystwyth University, who was involved in the research project during his PhD, says the recent research demonstrated that rumen fluke is extremely common in Wales – it was found on 61 per cent of surveyed farms.

“Despite its common prevalence, clinical disease remains rare in the UK, although we have seen some serious cases where high mortality rates were observed in young cattle and sheep,’’ he points out.

In these cases, small intestines were infected with enormous levels of juvenile rumen fluke after animals had grazed wet pastures during the autumn, leading to watery diarrhoea, weight loss and mortality.

No licensed anthelmintic is available to treat rumen fluke infections in the UK.

But Dr Jones says oxyclozanide, which is licensed for treating adult liver fluke infections, is effective against all rumen fluke stages, although optimum dosage rate varies from the liver fluke dosage noted on the product’s label.

With limited treatment options, Dr Jones says temporary fencing of infection risk areas or a simple rotational grazing strategy to ensure vulnerable animals are not exposed to fluke are helpful.

These strategies can be highly effective, although mud snail habitats must initially be accurately identified.

“The environmental DNA tools we are developing at Aberystwyth University will hopefully allow farmers to accurately identify and map these habitats in future and confidently manage fluke infection risk areas,’’ says Dr Jones.