Farmers should be aware that parasite control is just as important once animals are at grass as during the housing period.
Research carried out by Merial Animal Health has shown more than 90% of UK dairy herds are carrying a high gutworm burden.
Merial vet advisor Fiona MacGillivray says: “Many dairy farmers don’t believe gutworm burdens are a problem, as they cause no obvious clinical effects in the adult cows. However, there is an abundance of independent research in more than 5000 dairy cows which clearly shows worming cows with eprinomectin improves both their milk production and their fertility.”
Research shows that treatment can improve milk productivity by up to two litres a cow a day. It also shows that treated cows eat more.
Maintaining feed intake in newly calved cows is essential. When food intake is compromised at this critical time, the negative energy gap increases. When a cow continues to milk off her back for a prolonged period, both her milk production and fertility can be significantly compromised.
Beef farmers may wish to tie in worming with the treatment of liver fluke. Treating for fluke after turn out can help to break the life-cycle of liver fluke and its intermediate snail host.
An “at grass” fluke treatment will help to reduce fluke eggs shed onto the pasture in the spring and summer, and reduce the subsequent risk of winter disease in cattle. An “at grass” treatment may also contribute to improved growth rates and enable farmers to maximise their animals’ growth from grass – which is their most cost-effective form of feed.
In fact, cattle treated against fluke at grass were shown to have 31% better weight gain compared to untreated animals, and 8% compared with cattle that were only wormed.
In terms of treatment timing, cattle should be treated eight to 10 weeks after turnout or exposure to infection.