Why Worm Cattle?

When we talk about “worming” cattle, we of course mean the opposite.  Our aim is to get rid of all of the worms that they are carrying.  For our farmed animal populations, worm infections are ubiquitous.  In this article we will discuss roundworms, lungworms and fluke.  These are the three big parasitical infections of cattle.  We will use the term “worms” to refer to both worms and fluke.  All are parasites that infect cows and cause disease.  Reports from abbatoirs provide us with good information about the current parasite burden in our herds.  One recent study indicated that two thirds of cows are infected with roundworm and liver fluke and one sixth are infected with lungworm.

Roundworms infect the gut of the cow.  They are picked up from infected pasture and can cause significant weight loss and milk yield drop.  A bulk milk test will give you a general idea of how infected the herd is.  Lungworms cause pneumonia in cattle.  Your local vet can test for them using a faecal flotation test.  Fluke infects the liver.  It is spread by tiny snails in pasture.  It can cause weight loss and production loss.  Fluke infestations can also make cows more suceptible to catching other diseases such as salmonella or black-leg.  There is a bulk milk tank test for fluke antibodies, again giving a general herd picture.

The main treatment for these three ailments is “worming” or “fluking” – combined with pasture management (pasture management can control the environmental stage of the parasite; rotating pasture where possible and draining bogs to deprive the fluke snail of it’s habitat).  There are several good products on the market to de-worm or de-fluke your herd.  Worming has been shown to increase weight gain, milk yield and fertility across a herd.    There are different strategies with worming – depending on product used.  However manpower is a big consideration – for this reason worming is often carried when the herd is mustered – like the second day of a TB test.  Some worming protocols recommend leaving a small proportion of the herd “unwormed” so that the parasites will not all develop resistance to worming.  The idea being that the non-resistant parasites will dilute the population of parasites who could potentially develop resistance.

All withdrawal period information for milk and meat should of course be complied with.  Always read the datasheet and consult your vet for guidance.  The treatment protocols for worming or fluking vary for each product, so it would be helpful to build a herd health plan with your vet to decide what is best for you.