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New South Wales worm update - May 2012

LHPA DISTRICT REPORTS

Lachlan LHPA

Eliz Braddon, Young. (eliz.braddon@lhpa.org.au):

In the eastern section of the Lachlan LHPA, average worm egg counts for all ages remained fairly even with last month at an average 765epg. This was varied from 4epg to 5288epg. 44% of property visits for the month of April were a result of fatal Barber’s Pole worm (BPW) infections in all classes of sheep (e.g. weaners, lambing ewes, rams) and an additional 32% of phone calls relating to animal health issues.

Also continuing this month was the less than impressive response by this worm to drenching with Mectin based drenches. Though the cooler weather should slow down the BPW life cycle to a minimum for the next few months, we will have considerable pasture contamination from the larvae overwintering so vigilance will be needed in spring. If you have cattle, it may be an idea to use them to “clean up” pasture that sheep have been in between now and spring.

Testing of pre-lambing ewes should be occurring 8-10 weeks prior to lambing starting so that you have a good window to drench if need be without putting too much stress on the ewes.

Belinda Edmonstone, Forbes (belinda.edmonstone@lhpa.org.au):

In the central area of the Lachlan LHPA average faecal egg counts for the month of April have ranged from 0-6180epg with individual counts ranging from 0-13600epg. Barber’s Pole worm is still the major cause of loss and high faecal egg counts. Some forward planning to prepare ‘low risk’ paddocks for weaning and lambing will be vital to try to keep on top of this worm. Knowing how the drenches are performing is also highly important. Do a DrenchCheck 10-14 days after drenching.

Katherine Marsh, Condoblin (katharine.marsh@lhpa.org.au):

Worm issues are still plaguing some producers. WormTests this month had an average count of 2098epg (range 16-14012epg). The property with an average count of 14012epg had individual counts ranging up to 107000epg! The property was losing lambs due to Barber’s Pole worm. BPW was also diagnosed as the cause of deaths on a number of other properties where the producer elected to drench rather than wait for a WormTest to be conducted.

Whilst BPW has tended to be the predominant worm type, Scour worms are still appearing in abundance in some tests. Whilst the cooler weather will hopefully dampen down BPW issues, producers are still reminded to be vigilant for worms. Also as lambing is approaching, producers arealso reminded to monitor their pre-lambing ewes for worms as ewes may see a relaxation in their immunity to worms at this time.

Tablelands LHPA

Bill Johnson, Goulburn, (bill.johnson@lhpa.org.au):

Not wishing to invoke any wormy curse, but by all indications we’re continuing to see a repeat of 2011. Heavy pasture contamination is causing rapid rises in worm egg counts after drenching on many properties. The full range of worm species is represented across the district, with Barber’s Pole and Black Scour the usual offenders. At the same time, pasture growth and quality have been knocked by a series of solid frosts. In 2011, this combination of factors took a big toll on lambing ewes. At that time, there looked to be plenty of feed in the lambing paddock, but it was often of insufficient quality for lambing ewes, and every mouthful was loaded with worm larvae.

Decide whether to give a pre-lambing drench based on worm egg counts. But remember last year that ewes on some properties were drenched pre-lambing, yet still died before lamb marking time, because of heavy worm contamination of lambing pastures. Many factors are considered when choosing a lambing paddock, including aspect, shelter, feed, predators and ease of supervision.

Recent grazing history should be front of mind this year, avoiding paddocks where wormy sheep (especially last year’s lambs) have grazed since summer. Some may even consider using a long-acting drench product.

A few tests have given early warning of the return of liver fluke. Throughout the drought, as springs, creeks and swampy areas dried up, the small snails that play host to liver fluke disappeared. In paddocks where fluke has been a problem in the past, it would be worth checking again to avoid being caught out by the return of this blood sucker. Dung tests in sheep and young cattle, or a more accurate blood test in cattle could be useful.

Jim McDonald, LHPA DV, Yass (jim.mcdonald@lhpa.org.au):

The Yass District is now experiencing a normal autumn with little rainfall and cool days followed by frosty nights.

This weather is now very favourable to our winter Scour worms – Trichs and Osters. Counts range from 120-520epg on properties that have followed a stringent control program through summer and early autumn.

Concern continues as conditions are ideal for larvae survival and pasture contamination is very high. This winter will again be a challenge to keep the worm burden of both weaners and lambing ewes in check. Some producers will be able to use cattle to help reduce some of the larval contamination; others may need to seriously look at the long acting treatments – capsules or injection – to control worm populations. In all cases a regular WormTest at 4 weekly intervals will need to be carried out along with a larval differentiation to work out what course of action is required and with what product. This year continues to be difficult and as the effects of Barber’s Pole subside, now is not the time to take your eye off worms.

Riverina LHPA

Gabrielle Morrice, Narrandera (Gabe.Morrice@lhpa.org.au):

A small number of WormTests conducted over the past month have shown worm egg counts to be low in those mobs that have tested. Mixed counts over previous months have lead to producers being encouraged to WormTest where possible.

Dan Salmon, Deniliquin (Dan.Salmon@lhpa.org.au):

A small number of tests coming through, low to moderate worm egg counts. There has been no evidence of clinical disease from worms. Tests now give us a good idea of pasture/paddock contamination and what to expect as we go through winter and get ready for spring.

Colin Peake, Hay (Colin.Peake@lhpa.org.au):

Very few WormTests have been coming through, which is a little disappointing. Numbers have been low, with no evidence of clinical disease. It has been very dry for the last 6 weeks after the good March rain. Feed is good, stock look well with no Scours. WormTest when appropriate, e.g. pregnant ewes before lambing and weaners, and according to what the season is doing.

Hume LHPA

Tony Morton, Wagga Wagga (tony.morton@lhpa.org.au):

The generally high but very variable pattern of egg counts has continued, with Barber’s Pole or Black Scour worms being the major problem. There were still some properties with very good integrated management practices with low egg counts.

As with other areas ML resistance is common, in one recent example Ivermectin was only 21% effective against Barber’s Pole worms and 68% effective against small Brown Stomach worms.

Regular egg counts remains the best tool available to assess what’s really going on in a flock, we have seen far too many recent examples of heavy production loss and deaths that could have easily been avoided with regular monitoring.

South-East LHPA

Bob Templeton, Braidwood (bob.templeton@lhpa.org.au):

In Braidwood, Cooma and Bombala, Barber’s Pole worm is still causing many problems in a lot of flocks. The rise of Black Scour worm with the cold wet weather is strong on some places but totally non-existent on others. One thing that is increasing is the resistance to Ivermectin by the major worms across the area in the past few months. With all this activity a midwinter WormTest is strongly advised.

Western Division

Greg Curran, Broken Hill (greg.curran@industry.nsw.gov.au):

Flock owners in the far NW (Broken Hill, Tibooburra Wilcannia, White Cliffs and Menindee) have begun to WormTest after hearing of worm problems, especially in the Bourke, Brewarrina and Cobar area.

Egg counts have been low, and mixed culture.

Sheep are holding condition well, no scouring; very low stocking density compared with both feed available and historical stocking rates. Feed is drying off, after a very wet Jan-March.

North-West LHPA

Plains areas Walgett, Narrabri and Moree – DV Libby Read and Shaun Slattery

Clinical cases of Barber’s Pole infestation around Narrabri, Moree and Walgett have waned over the last month.

WECs have been variable with most counts below levels requiring action for Barber’s Pole worm (usually after good control over summer). However there is still a reasonable portion with substantial subclinical burdens.

As these subclinical burdens will quickly contaminate pastures in spring with any rainfall, we are currently recommending all flocks perform WECs.

On a positive note, the very dry conditions since the floods of early February mean that there have been few Barber’s Pole worm hatching opportunities since then. As such we expect that on pasture larval contamination in spring, from over wintered larvae, should be minimal.

Western northern slopes Warialda, Bingara – DV Ted Irwin

Similar picture to the plains with no clinical cases of Barber’s Pole worm infestation reported or investigated in the last month. An absence of WEC monitoring by producers makes further assessments difficult.

Central West LHPA

Evelyn Walker, LHPA DV, Dubbo (evelyn.walker@lhpa.org.au):

In last month’s WormBoss article, I spoke of quarantine drenching newly introduced sheep with 3 to 4 different chemical groups as potential drench options for newly introduced sheep. I neglected to mention however, another potential quarantine drench option from a new potent chemical drench class, the Amino-Acetonitrile derivative drench group (or AAD), called Monepantel. Regardless of which quarantine drench you select for your farm, it is important to check the efficacy of the drench with a worm test 10-14 days after drenching.

In other news, the Central West is still not immune to the Barber’s Pole worm. Deaths continue to be reported. However, the deaths seen lately don’t appear to be from ineffective drenches, but rather from high levels of worm exposure and contamination. On one property, a farmer drenched two different mobs of sheep (pregnant ewes and wether lambs) with a triple active combo. The pregnant ewes went into a clean paddock and were doing well and the wether lambs that were going to be sold very soon, went back into the same paddock.

Unfortunately, the wether lambs that went back into the same dirty paddock experienced severe losses just 2-3 weeks after drenching. It’s important to remember that when treating worms in sheep (even with an effective drench), shortcuts cannot be taken. By using clean paddocks, you are reducing worm exposure levels and improving the life of your drench.

Drench + Dirty paddock = 3 Big D’s (Dead sheep, Dollars lost & Drench resistance!)

Treating worms in sheep requires a well-rounded treatment approach involving effective use of drenches based on worm counts, drench rotation, good pasture management, good nutrition, and breeding resistant sheep.


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