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New South Wales worm update - September 2012

LHPA DISTRICT REPORTS

Lachlan LHPA

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

In the eastern area of the Lachlan LHPA, average faecal egg counts for the month of August have been 1088 epg for ewes and 2217 epg for weaners, with a range of 16-8960 epg. Scour worms are predominant but we are also starting to see the reappearance of Haemonchus (Barber’s Pole worms) as the weather warms up.

The main groups that have been caught out have been lambing ewes that were drenched prior to lambing but then forced to graze on contaminated pastures. Generally they have then started to show signs of worm infestation just prior to lamb marking, making things a bit difficult as ewes and lambs are having to be mustered earlier than planned.

For scour worms (Trichostrongylus and Teladorsagia), the first sign is scouring in the mob and weight loss. Now that we are moving into warmer spring temperatures, it may become necessary to drench lambs through the cradle at marking to reduce these scour worm burdens.

A worm test first is the way to go about two weeks or more before lamb marking is due and trying to get lamb samples as well as ewes (e.g. 1-5 jars ewes, 6-10 jars lambs). Care needs to be taken with drench choice if lambs are to be drenched in the cradle. Make sure the product is suitable for young lambs.

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

In the central area of the Lachlan LHPA, average faecal egg counts for the month of August have ranged from 0-1400 with individual counts ranging from 0-2360. Scour worms have been the main cause of loss. One main issue is although sheep have been drenched with an effective drench, they are not put on to a clean paddock. These sheep are becoming reinfected, with clinical cases presenting 4-6 weeks post drenching. Producers must plan ahead and prepare low-risk paddocks for weaners and lambing ewes.

Tablelands LHPA

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

A staggering number of doses of drench capsules and long-acting drench injections have been used this lambing season, and have certainly helped to avoid a repeat of last year’s dramatic ewe deaths. Only a handful of places have run into worm trouble over lambing this year, again caused by black scour and brown stomach worms picked up from contaminated paddocks.

Defying the trend, however, a few producers have successfully guided their flocks through one of the worst worm seasons on record using only a minimal amount of short-acting oral drench, combined with close attention to pasture management, and regular worm monitoring.

Their efforts give continuing confidence that despite more district flocks comprising mainly breeders, you don’t have to rely on chemicals alone to control worms in sheep.

There have been a couple of surprises in recent worm egg counts. Of nine mobs tested on one property, six were negligible and two were borderline, while one mob of mixed-aged ewes averaged more than 3200egs per gram. On another big place, four weeks after healthy ewes were drenched onto paddocks not grazed since April, worm egg counts averaged 1600epg. Both cases are a reminder that barber’s pole worm larvae on pasture have survived the coldest winter in a decade. The days are also now warm enough for barber’s pole eggs to hatch. Now would be a good time to do a worm test and culture on mobs in paddocks that were affected by barber’s pole last autumn.

And a reminder to think about the possibility of liver fluke in sheep, cattle and goats near creeks and swampy areas.

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

The Yass district continues to experience great conditions for our winter scour worms, with a below average temperatures through winter, overcast conditions and adequate rainfall.

There has been next to no larval kill on pastures, which has continued to cause problems within five weeks of administration of short-acting drenches. I visited one goat herd recently where counts had risen to 6000 epg 8 weeks post treatment.

The signs for continued worm problems through spring are very clear and constant monitoring of young stock at least every three weeks is a necessity.

Heading into weaning in late spring, consider that on the majority of holdings, weaners will be subjected to high levels of contamination irrespective of paddock selection.

Riverina LHPA

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

No WormTests have been conducted in this area in the past month.Some clinical cases of rapid reinfestation of weaner lambs have been investigated, reinforcing the need for paddock preparation and planning for this vulnerable class of sheep.

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

There have been only three WormTests received in the last month and all three had zero counts. The local Hay private practitioner, Wayne Gardam, reported a case of clinical disease with significant numbers of Teladorsagia (Ostertagia) and Nematodirus on a worm count in a weaner. This reinforces Gabe’s comment about the need for paddock preparation and planning for this vulnerable class of sheep.

Dan Salmon, Riverina (dan.salmon@lhpa.org.au):

We have had a few WormTests with variable results. One group of merino ewes from Rand had an average FEC of 420 with 25% Haemonchus, 48% Trichostrongylus and 27% Ostertagia. A mob of lambs brought onto irrigation from their pastoral birthplace were losing condition and scouring. I confidently diagnosed worms and then did a total worm count to show the owner that I was right. There were 900 Teladorsagia and 400 Nematodirus, but significant lesions consistent with Coccidiosis.

Several WormTests were as close to negative, following a summer drench six months earlier.

Central West LHPA

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

We are seeing various levels of worm activity ranging from low to high worm egg counts this spring. The mild winters we experienced, survival of the worm larvae on pasture and contaminated paddocks have contributed to early Barber’s Pole worm infestations in some areas.

For example, on two different sheep properties in the Dubbo area, the overall average strongyle egg counts were 1,100 and 1,400 epg. The predominant worm type was Barber’s Pole.

Sheep producers are strongly encouraged to start monitoring their sheep flocks now with worm egg counts. Some of the producers in our area are even participating in on-farm drench resistance testing. Of the resistance tests conducted, mectin resistant Barber’s Pole worm is a common feature. However, the degree of individual drench resistance varies from farm to farm.

Although using an effective drench for your worm type is integral in worm management, other factors like good nutrition and pasture management are just as important in keeping on top of the worms.

For example, one sheep producer used an effective knock down drench on his weaners; moved them to a clean paddock (a paddock that had been spelled for more than three months); supplementary fed them with grain; and five months later, the worm egg counts remained very low for this mob - an overall fantastic result.

Charlotte Cavanagh, Veterinary Officer, NSW Department of Primary Industries, Bourke (charlotte.cavanagh@dpi.nsw.gov.au):

Only three worm tests this month, but as they come from three very different parts of the LHPA area, they give a nice insight into what's happening out here.

Results range from 256 epg to 420 epg. Only one larval differentiation came through at this stage, with 67% Haemonchus and 33% Trichostrongylus. This result was from a mob of 10,000 Dorpers run as one mob, on a monthly paddock rotation, so samples come from all classes of sheep.  

The temperature is rising in this area, so with some much needed rain the Barber's Pole worm may increase in numbers reasonably quickly.


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