A new drench family, and test for genetic resistance

New drenches arrive just in time

Rural News

New drenches arrive just in time

17th Sep 10, 3:39pm by Tony Chaston

Resistance to anthilmentics in the sheep industry has been a growing and worrying problem for some time.

Two new drugs released by animal health companies Novartis and Pfizer to solve the resistant intestinal worm problem, come as a complete surprise. Farmers had been repeatedly told the deveolpment of a new drench family was years away.

Like any new product the costs will increase by 4-6 times over existing drenches, although AgResearch scientists state that drench resistance can cause a 14% drop in carcase value.

Farmers need to test for resistance to quantify the problem on farm, and look at breeding sheep selected for resistance to worms, before they increase their animal health bill. If they have resistance a double pronged attack, using sheep bred with resistance, and judical use of the new drench should allow good control of these costly parasites.

In all the doom and gloom about the future of sheep farming - high costs, low profits, bad weather and a disjointed meat industry - a hugely important advance has been overlooked.It is the introduction of two new drenches, and it is no exaggeration to say they have snatched NZ sheep farming from the brink of disaster. The drenches are drugs that kill internal parasites in sheep reports The Dom Post. The drenches we use now are coming to the end of their usefulness. The three drench chemical families are decades old and parasites have evolved to withstand them. In the farming world it's known as resistance.

The hope now is that the new drugs can be used to prolong the old drugs' lives. The new drugs, launched by animal health medicine giants Novartis last year and Pfizer two weeks ago, have come as a complete surprise. The new drenches cost more. They are 85c to $1 a dose, compared with 15c-25c a dose for the old ones. A farmer would have to see real value in making that change. AgResearch scientist Dave Leathwick, a leading authority on the subject, says trials have shown that drench-resistant parasites cause a 14 per cent drop in carcass value.

However, many farms may not need to go to one of the new drenches. The old drenches may still be effective. A simple test can resolve this. At a cost of $1000 over three years, the drench resistance of a flock can be measured. Dr Leathwick is mystified why more farmers don't test their flocks. Some farmers are breeding sheep that are so parasite-resistant their growth is unaffected.

AgResearch today launched a revolutionary technology which measures natural immunity to internal parasites in sheep more quickly, accurately and easily than existing tests. The CARLATM Saliva Test, which measures protective antibodies to worms, has been used on over 7,000 animals this year. Sheep breeders are now able to identify their naturally parasite-resistant sheep and select them for breeding.

“The CARLATM Saliva Test was successfully trialled last season with 14 farmers and over 7,000 sheep. Saliva sampling itself takes about 30 seconds per animal; a dental swab is rubbed in the cheek pouch for around 7 seconds and then placed in a labelled vial,” said Richard Shaw.

The timing and strength of an individual CARLATM antibody response is strongly influenced by an animal’s genetics. The heritability of the CARLATM antibody response is high (about 0.3 or 30%).

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1 Comments

by Steptoe | 18th Sep 10, 2:46pm 1284777979

I have often wondered about worm drenches and stuff.

We breed parrots, in particular native kakariki, and captive birds are reputed to be rather prone to worms and mites. We have anything from 40 to 80 parrots at one time.

Some yrs back I had a theory that diet and environment could be used...or put another way, recreate a natural diet in captivity. My grandfather used to put the old tea leaves in his troughs to keep on top of worms, successfully.

Birds dont eat tea thu, but they do have access to vinegar .We have mist sprayed our aviaries and birds every 6 to 8 weeks with a 50/50 soln of vinegar and water...malt, white , spiced what ever is in the pantry. Also once a week/10 days a few teaspoons of Apple cider vinegar is added to their daily chopped veggie mix.

Since about 2005 we have never had to worm our birds or had a mite issue...regular checks for eggs in the droppings using a microscope and brine to float them, show no instances. Birds we have supplied to DoC checked at Massey came thru clean.

We do use a couple drops of invermectin and repeated 12days later for any birds sourced else where, and they are isolated for a good month.

My theory was that acetic acid, and possibly citric acid act as a buffer in the blood stream...when we/animals get sick the Ph goes off the normal and once it does the bacteria, worms , mites etc cannot breed as they intended to create there environment and die off.

Im not tree hugging green or natural remedy nutta, on the other hand I think drugs are no more than a tool to use because of poor diet environment induced illness s.

Another illustration ...accidental thu,...we do regular maintenance for rats mice, prevent better than cure ,right? I put a block of rat poison in one of the aviary safety enclosures, a large king parrot open the door and got into the rat pioson...was scattered everywhere...we did not notice for a couple days he had done so...Panic..internet found that Vitamin Ki is the antidote, up to the vet for a tablet used on dogs to divide up with a razor blade. The vet said he hold no hope for the bird and that was the advice we got everywhere, espec considering the time frame....The bird survived quite happy as if nothing was wrong.

Why? i asked my self..so I dug into the diet and found one of the ingredients was very high in Vit Ki..I also recollected over the yrs that in recent time a bird would hit the mesh, split its forehead open and we would not worry knowing it would stop bleeding. Same if a toe was lost etc...yet in the early days a lost toe would not stop bleeding and we would use Silver nitrite sticks to cauterize.

A sheep or cow in a paddock is a captive animal, not able to source a full balanced diet unless supplied by the farmer, no different to a bird in a cage or aviary.

A side note to the vinegar and apple cider...since publishing this theory on www.kakariki.net we have had ppl coming back including top international show breeders Strating it works, but also their birds have far better feathers, more life, zing, and are taking out prizes in international European shows.

I wonder if there is a farmer who every week or so would throw a bottle of vinegar or apple cider vinegar onto a bale of hay, mix it up and put out into a paddock for his animals?...or even in the drinking water as one English parrot breeder I know of is now doing, and swears by it.