Summer rainfall/slopes and plains
Merino wool and prime lamb production
Don Perkins doesn't remember worms being much of a problem in sheep when he was growing up on ‘Nelyambo’, near Dirrandbandi, in southwest Queensland.
His father David would usually drench at shearing and always warned his children to keep an eye out for worms when sheep were on a declining plane of nutrition, particularly ewes in lamb.
In the past ten years though, the rising incidence of barber's pole worm has left Mr Perkins scratching his head over how to successfully control the parasites in his 7000 Merinos.
It's a problem he hopes to go some way towards solving with the help of $1000 in consultancy fees, the result of winning the Queensland section of the WormBoss ‘Take control of worms’ promotion.
Mr Perkins is working with Goondiwindi vet, Dr Mike Rival, to learn how to do worm egg counts at home and has already discussed grazing options and the possibility of using rams bred for worm resistance in an effort to get on top of the problem.
Mr Perkins says barber's pole is a major challenge for growers in the Dirranbandi district and a lot of people are frustrated by the worm's persistence.
“We don't seem to be able to get the paddocks clean,” he says, “And the notion of running more cattle to reduce the worm burden isn't really practical here, because in the good years, we just don't have enough cattle to make a significant difference.”
Dr Mike Rival says it's a problem that wasn't around in the 70s and 80s when 20 years of closantel kept a lid on the problem.
“In the past when graziers generally ran a self-replacing Merino flock breeding wethers and running a few cattle, they used rotational grazing as an integral part of the WormKill program says Dr Rival. The wethers and cattle acted as a sort of biological slasher, he says, vacuuming up the worm larvae and busting down long grass, but things are different today.
“Now with the market so good, wethers are sold off as weaners and if you're not cropping it’s a challenge to keep paddocks clean.”
Mr Perkins joins 3500 ewes, 2500 to Merino rams and another 1000 to Poll Dorsets for the prime lamb market, selling the crossbred lambs at weaning and his Merino wether weaners off oats.
‘Nelyambo’ covers 8100 ha and ranges from black soil Mitchell grass to heavy flood country, interspersed with clay pans and sandy loam growing large stands of buffel grass.
In a major flood year like one, sheep were boxed together in the middle of the property to avoid flooding to the east and west. After an excellent summer, they congregated around the edges of the clay pan country without venturing too much into stands of buffel grass that had grown to over 70 cm.
Mr Perkins sends faecal samples from the different mobs to the Wormbuster lab in Brisbane for worm egg counts every few months, and is selective about the type of drench he uses after doing a drench resistance test five years ago.
It showed we had some degree of resistance to the BZ and closantel drenches, so we use the long-acting drenches only when we really have to and generally use the short-acting drenches to prevent resistance building up.
Don’s also not averse to leaving worms in the sheep if they’re at a manageable level just to ensure the sheep maintain their immunity, but that means keeping a close eye on the season; he reads the monthly WormBoss emails to check what’s happening across the state.
“Sheep can handle a fair burden and I wouldn't worry about dry sheep with up to 1000 eggs per gram if the weather is dry and pasture is of good quality, but if it's November and it starts getting wet, barber's pole can build up very quickly, especially in ewes and lambs,” he says.
“The problem is, every season is different.”
Mr Perkins is also open to trying different grazing methods
“It may be a case of trying more rotational grazing with the ewes in bigger mobs after weaning and before joining, so that they have access to feed, but don't stay in the paddocks too long,” he says.
“Dr Rival says the timing of the first frosts may also play a part in controlling the worm.
In the New England, they usually get the first frosts at the start of April, but it’s later here, in June, and if there's a good body of feed the barber's pole larvae can keep developing well into the winter,” he says.
He's encouraged Mr Perkins to consider using rams that have been bred with genetic resistance to worms, but says gaining instant results from egg counts at home will be a good start.
WormBoss has been developed by Australian Wool Innovation Ltd and the Australian Sheep Industry CRC, with support from Animal Health Alliance (Australia) Ltd.