Bulk milk surveillance for stomach worm exposure in dairy cows has found high levels in 68% of herds, with "probable sub-clinical effects on health and production", according to Pfizer Animal Health.

Between September 2011 and March this year, 449 milk samples submitted by dairy vets and SQP animal health advisers were analysed independently for Pfizer VPS.

Pfizer VPS vet Andrew Montgomery says that stomach worm (Ostertagia ostertagi) is the species identified most often in dairy cows1,2. and known to suppress appetite3: "Numerous trials have found a yield response to worming treatment, typically in the region of 1kg/cow/day."4

"At 25p/litre, this would be worth £76/cow over a 305-day lactation, or about £16,500/year in a typical 200-cow herd. Some trials have also identified improvements in reproductive performance although this remains to be proven absolutely."4

When test results indicate that worming is justified, Andrew recommends a moxidectin pour on treatment in the late dry period to maximise the gain over the highest yielding, early part of lactation.

The bulk milk surveillance programme is ongoing, and free Pfizer test kits are available from participating VPS animal medicine suppliers and veterinary practices.

References

  1. Agneessens J et al (2000) Veterinary Parasitology 90, 83-92.
  2. Borgsteede FHM et al (2000) Veterinary Parasitology 89, 287-296.
  3. Forbes, AB et al (2004) Veterinary Parasitology 125, 353-364.
  4. Charlier, J et al (2009) Veterinary Parasitology 164, 70-79.

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