Farm Ireland

Thursday 27 October 2016

Breaking the grip of parasites

The correct timing of treatment and selecting the right products are critical to ensuring cattle remain in good health when housed for the winter

Gordon Peppard

Published 25/11/2015 | 02:30

An effective treatment programme shortly after housing will keep cattle free of parasites until they return to pasture or are slaughtered.
An effective treatment programme shortly after housing will keep cattle free of parasites until they return to pasture or are slaughtered.

As cattle come off grass and are housed for the winter, they bring in with them a huge burden of parasites.

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Without treatment these parasites can do a lot of damage, reducing thrive by causing a drop in appetite and feed intake thereby affecting performance. If untreated these parasites can reinfect pastures after turnout and keep the cycle going.

Housing is one of the best times to break this cycle and treat cattle against the most common internal and external parasites. So what parasites are we targeting at housing?

The main ones are stomach worms, lungworms, liver fluke and lice, whilst rumen fluke may need to be taken care of, if an issue on individual farms. The number of parasites carried by cattle at housing can vary according to a number of factors, their age, health status, grazing management and level of previous treatments.

As cattle cannot pick up worms and liver fluke while they are indoors, an effective treatment programme shortly after housing keeps them free of these parasites until they return to pasture or are slaughtered.

The choice of product to use and the correct timing of the treatment then become the critical questions to answer.

Many of the above active ingredients are found in combination products, but be sure to check the label for efficacy against various stages of parasites and consult your vet if you are in any doubt.

These parasites are very difficult if not impossible to get rid of at farm level and can cause both clinical and sub clinical losses on your farm, therefore the rationale for their control is good and the housing period provides an excellent opportunity to simply treat a broad spectrum of parasites at the one time.

Difficulties in treating Liver Fluke

It is very important to understand the different stages of the liver fluke lifecycle, as a lot of products will only control adult liver fluke, but liver fluke have distinct stages, go from early immature to immature followed by adult fluke.

In a cattle situation for example, going in too early with a dose after housing will not kill immature fluke and within a matter of weeks they will have developed into adults.

If the flukicide used at housing is only effective against older immature and or adult liver fluke, then faecal sampling six to eight weeks later is recommended to see if more fluke have developed and a further dose is required.

Alternatively, fluke treatment can be delayed until at least six weeks after housing until most of the fluke have developed to at least the immature/adult stage and are susceptible to the treatment.

Dosing with a triclabendazole two to three weeks after housing should kill all the stages of fluke present and therefore a follow up treatment should not be necessary.

For cattle that are to be slaughtered out of the shed be aware that flukicides tend to have a long withdrawal period, typically between 50-60 days.

Indo Farming