The latest MOO Test figures from Merial Animal Health suggest that the productivity of nine out of ten dairy herds in the South West is compromised by high levels of gutworm.

Merial Animal Health has been helping dairy farmers to assess the level of gutworm exposure in their herds since 2009 by supporting and promoting MOO Tests. This bulk milk test assesses the level of antibody to gutworm (Ostertagia ostertagi) in the sample and can determine if the herd’s gutworm exposure is low, medium or high.

At 90 per cent, exposure to gutworm in the South West is slightly above the national average of 88%.

Data from five years of MOO Tests shows that whilst there was a steady reduction in the number of herds with a high exposure between 2009 and 2013 nationally, the figure rose in 2014. In 2009, 93 per cent of herds tested high and by 2013 this had fallen to 71 per cent but this rose to 88 per cent last year.

Whilst these figures show an overall reduction in exposure since 2009, levels of gutworm across the UK dairy herd are still very high, especially in the South West. Those animals affected will suffer from the negative impact of gutworm on productivity and fertility.

Between 2009 and 2014, 260 MOO Tests were conducted across the South West. During that time several counties had significant numbers of herds with high gutworm exposure results. This included Cornwall (93 per cent), Devon (92 per cent) and Somerset (86 per cent).

Sioned Timothy, veterinary adviser for Merial Animal Health, said: “Gutworm can significantly reduce the productivity of the herd. Although adult dairy cows develop immunity to gutworm that makes them resilient to outward clinical signs of infection, it does not prevent them from becoming infected with Ostertagia ostertagi. This parasite burden can reduce milk yield by as much as 2.6 litres per cow per day”

She continued: “Gutworm may also have an impact on fertility. Treating dairy cows for gutworm may improve their fertility, reducing the calving to conception interval and improving conception rates.”

Calving is another key period in the production cycle. Optimising cow and heifer management during this period is critical to the animal’s health and productivity throughout the lactation. Cows treated for gutworms around the time of calving have been shown to increase their grazing time by almost an hour compared to untreated cows. Improved appetite and higher dry matter intake helps cows to bridge the energy gap, maximise their production, and reduce the time it takes to get them back into calf.”

Ms. Timothy concludes: “The MOO Test figures show that the UK dairy herd continues to be affected by high levels of gutworm exposure. At a time when maximising productivity is vital to dairy business success, farmers should seriously consider testing their herd this autumn and discuss a treatment plan with their vet or animal health adviser (SQP - Suitably Qualified Person).”

MOO Tests will be available in autumn 2015. Farmers should ask their vet or animal health adviser (SQP) for more information. The results of MOO Tests are sent to both the farmer and their vet or animal health advisor (SQP), to enable them to determine the best course of action and treatment.