BREEDING and drenching help whip worms, writes ANDREW MOLE
Matt Tonissen has 3500 crossbred ewes and two sheep studs on his property outside Hamilton.
And he is planning to almost double that to 6000 ewes within 12 months.
One of the keys to the growth and success of his Chrome crossbred and Icon Poll Dorset studs for this third-generation producer is parasite control.
In the Western District, traditionally and currently wet and cold right through winter and into spring, that means worms.
Lots of worms.
"Over the past 10-15 years we have worked progressively to cope with our worm burden," Matt says.
"That has been a blend of selecting for resistant sheep, rotational grazing and careful and planned use of drenches.
"With the hardy genetics we have bred into our stud, which is based on the Coopworth, we have naturally found animals that not only cope with the worms, but can shed their burden.
"The Coopworth, and the Romney, are generally tough breeds, and over the past four years we have been introducing Perendale bloodlines as well, which have a component of Cheviot in them, and they would be the toughest of them all."
In parallel with this natural selection, Matt (pictured) runs a dedicated faecal egg count program in conjunction with Hamilton vet David Rendell, a recognised authority in the area of parasite control.
He says the FEC program has played a key role in this performance of his flock.
"The regular FEC program is part of our total ewe flock standard practice, and rarely would we drench with the results based on the egg count," Matt adds.
"Routinely before lambing most people deliver a traditional drench, but unless our FEC says it needs to be done, then it isn't.
"But David Rendell has devised a triple-combination program based around Avermectin and Rametin when we drench .
"It is working well for us and I have a lot of faith in David because he has built up enough flock data where he has been able to turn around serious resistance.
"This is strategic parasite management, not just shoving a drench gun down a sheep's throat."
Matt has also helped address his worm problem through grazing management.
He has grown more grass so sheep have a better crack at building a natural resistance.
"We can cope with 300 eggs-per-gram in our weaner ewes, provided they have feed in front of them," he said. "Some of our sheep, which were weaners in 2005, have not been drenched since then.
"With the rotational grazing and good-feed conditions, they managed to get themselves back to 200-eggs-per-gram. I think with our selection program for resistance, by giving them a subtle challenge when they are young and enough feed to help them with it they develop a kind of immunisation."
Matt's sheep need to perform because none of his stud flock ewes can be drenched after turning two.
It is a significant part of his marketing, and of ensuring he has a self-replacing enterprise.
He said, with so many producers having had a gutful of buying expensive ewes, his drive to build a ewe flock based on maternal Coopworth traits with a composite on top has proved a winner. "Right now, we sell rams, with EBVs, to five states," Matt said.
"We have been using EBVs since 2000 and being able to back them up with proven performance in our worm resistance is a big plus.
"Chrome is all about fertility, which is all about a healthy ewe, and, with the accuracy of our EBVs improving all the time, that is what we are delivering."
Lambing in July-August, Matt said he expected to mark about 180 per cent lambs.
"If a ewe is not twinning by the time it is two, it is culled regardless of its figures," he said.
"There is also a lot of visual assessment here, which gives us another chance to check the overall health of each animal as well as its conformation."
The University of Melbourne's Mackinnon Project has shown on a typical Victorian sheep farm, with 2000 sheep, treatment costs and lost production from worms can range between $5000 and $10,000 annually.
Mackinnon says scouring and deaths are the obvious signs of poor worm control, but moderate worm infections can account for a 20 per cent reduction in growth rates and 30 per cent less wool growth in young sheep, and a 10 per cent reduction in wool growth in adult sheep.
