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Chemvet Newsletter Volume 7

The spring has bought mixed fortunes to many of our clients throughout rural Australia.

Many of our clients have received the first ‘real’ spring rains after several years of ‘end on end’ failed springs – many cropping areas received a drink right in the nick of time turning potential failures (once again), or hay at the best, into now flourishing grain yields. Some areas in the western district

of Victoria are even suffering a bit from water logging. On the other hand some areas are suffering yet again another failed spring. North eastern NSW after all those flooding rains of the summer and autumn are as dry as chips again.

For those still struggling season wise it has to be your turn next!!!

We have very recently added a couple of products to our range – more over the page.

Lots of clients phone in for advice with regards to lice infestation within their herds. We have included a quick run down on cattle lice and how Vetmec can be used to treat lousy cattle.

Kind regards, Murray Grant

Fluke Warnings for NE NSW

It appears that the Department has issued several warnings prompting beef and dairy producers in the northern coastal and river regions as well as the New England region to be vigilant with liver fluke control leading into the summer.

Early flooding, above average temperatures and a later dry spell prompting cattle to push into the remaining soaks and springs chasing the green pick appears to have lead to heavier than normal fluke infestations.

Treatment with a fluke effective product such as Vetmec F in the spring and again in the autumn for those fluke picked up post this spring treatment is advised.

Cattle Lice

Lice irritate cattle, causing the cattle to bite, scratch and rub. The coats of lousy cattle take on a rough scruffy appearance, and, at times, areas of skin are rubbed raw.

Lousy cattle cause damage to fences, yards or trees which the cattle use as rubbing posts. Damage to hides can also occur.

The effect of lice on the production and growth rate of cattle is a matter for continued debate however lice can be an important cause of economic loss when cattle are in poor condition or if infestations are heavy.

There are two types of cattle lice: biting lice and sucking lice.


Biting lice

Biting lice are reddish-brown, about 2 mm long with a brown head.

They feed on skin debris, are mostly found on the neck, shoulders, back and rump and can cause severe irritation. Note the head is almost as wide as the body.

Sucking lice

Sucking Lice are grey to bluish black and vary from 1.2mm (pin head) to 5mm long. In Australia there are 3 main types of sucking lice.

Sucking lice pierce the skin and suck blood. In large numbers they can cause anaemia. Note the head is a lot narrower than the body.

 The life cycle

It is now believed that if cattle are scratching heavily because of lice, treatment is recommended.

The life cycles of all cattle lice are similar. The entire life cycle takes place on the beast. Eggs (nits) are laid by the female and glued to hair shafts, and take 8-19 days to hatch as nymphs. The nymphs undergo three moults on the beast, and develop into adults. The entire life cycle takes 3-6 weeks. Lice are spread entirely by direct contact between cattle. The lice and their eggs survive for only a few days if removed from cattle. Cattle lice cannot live on other species of farm animals.

Lice populations are highest in winter and lowest in summer. Cooler skin temperatures are associated with heavier lice infestations. The denser winter coat and cooler weather favours survival of lice.

Is lice treatment necessary?

Many experiments have shown that the treatment of cattle that have light to moderate infestations is not economically justified in terms of improved growth rate and body condition. However, in recent years there has been increasing emphasis on hide quality, and there is evidence that the majority of

hide damage occurs when cattle are scratching due to the presence of lice. It is now believed that if cattle are scratching because of lice, treatment is recommended.

Treatment with Vetmec

Most insecticides registered for use on cattle are not very active against louse eggs. And after most treatments, eggs will still hatch.

An effective treatment has to last long enough to kill the larvae as they hatch, preventing them from developing into adults, laying further eggs and hence continuing the infestation

Treatment with Vetmec and Vetmec F Injection

Both Vetmec injection and Vetmec F injection, as well as treating internal parasites (worms and fluke), are very useful in treating lice infestations in your cattle. The avermectin in the blood stream will last long enough to kill the larvae arising from the eggs already on the cattle at the time of treatment.

However, like all of the injectable mectin’s, they can struggle if the herd is infected with mostly biting lice. This is because, as mentioned above, biting lice only feed on the skin scurf and although after injection, there is a high level of the active compound in the blood, there are very low levels in the skin scurf and debris.

However a very good result is achieved if the majority of the lice are sucking lice as these get a good dose of the active when they feed on the beast’s blood.

Unlike some of the pour-on single purpose lousacides, that can last for a number of months, Vetmec and Vetmec F Injection doesn’t last in the blood stream long enough to cover multiple lifecycles of lice so therefore, if treating lice in the herd is important to you, it is essential that you treat all the animal that will come in contact with one another over the winter all at the same time or within say a week of each other

Treatment with Vetmec Pour-on

Vetmec pour-on because although a lot of the treatment finds its way into the blood stream the mere fact that it is a topical treatment with some of the active spreading around the coat from the site of treatment or from grooming it is highly effective against both sucking and biting lice. We will normally recommend treatment with Vetmec pour-on if treatment for lice as opposed to worms is your major consideration.

Again it is important to treat all the animal that will come in contact with one another over the winter all at the same time or within say a week of each other if lice control is of major importance in your herd.

Vetmex Mineral Mix

Many of our sheep producers have asked for a fully mineralised form of our popular Vetmec LV plus selenium.

In response we have produced Vetmec Mineral Mix which contains a number of essential trace elements for sheep and goats – Copper, Cobalt Iodine and zinc.

Each of these trace elements are in a special chelated form which are highly soluble and readily available to the animal compared with other forms of these trace elements.

Vetmec Mineral Mix can be mixed with 10L of water or simply added to a 10 L of Vetmec LV. If mixed with Vetmec LV plus Selenium the resulting mixture has been shown to remain stable for up to 2 years

Vetmec Mineral Mix is priced at $50 + GST or 2.0 cents per adult sheep (50 Kg)

Vetmec Dual

Vetmec Dual Oral Drench for Sheep and Lambs is as the name suggests a combination of a white and a clear drench. It is a low volume formulation containing Albendazole and Levamisole. Many sheep producers use such a product concurrently with our Vetmec LV plus selenium to produce a very economical ‘resistance breaking’ 3 way combination drench.

Most parasitologists are now recommending the continual use of a combination of effective drenches rather than drench rotation so hopefully with this drench we are providing a complete solution to your sheep drenching needs.

It may provide the solution for many years to come and enable you to ‘keep up your sleeve’ any new highly expensive drench class about to come onto the market.

Vetmec dual is highly effective against tapeworms so this may be the answer for those of you who wish to treat for this parasite in your lambs.