NSW WormBoss Worm Control Programs
NSW WormBoss Drench Decision Guides
NEW SOUTH WALES
The recent good rainfall across the New England region (and further afield) will have stimulated worm activity. In recent weeks, the Veterinary Health Research (VHR) Laboratory has seen a rise in worm egg counts (WEC); typically Haemonchus dominant infections, reflecting the current favourable conditions. Sheep producers should be “stepping up” their worm monitoring program so as to identify worm issues before they materialise.
Nonetheless, a not insignificant number of properties have been recording low to quite moderate WECs (less than 350 epg mean) in ewes approaching lamb marking. This reflects good paddock preparation, assisted by a dry early spring. Graziers in such a position have been able to take advantage of this fact by withholding a lamb marking drench. This is of great benefit in terms of managing drench resistance, an issue that cannot be overstated in this region.
Conversely, a few examples of sub-optimal lambing paddock preparation and the ramifications to worm control over the lambing period have also been seen. In one instance, XB ewes with very low WECs just prior to lambing (mid-August) were placed in paddocks considered to be “clean” by the manager (had no sheep grazing for minimum of 4 months), yet were in fact still highly contaminated from lambs grazing the paddocks in March*. The result was that the ewes had a mean WEC in excess of 3000 epg within 6 weeks, necessitating an early lamb mark and ewe treatment. The value of worm monitoring is highlighted in this example as the issue was identified prior to worm symptoms and significant production loss becoming apparent.
Weaning paddock preparation is also equally important. Paddocks that can be currently identified as “low worm” status (no spring worm development) should be reserved for post-weaning grazing.
*Editor’s note: WormBoss recommends a 6-month period for preparation of low worm-risk lambing paddocks—see the WormBoss worm control program on how to do it without actually spelling paddocks for 6 months.
No activity in the Bourke areas and no worm egg counts conducted.
Producers in the Coonabarabran region have begun to see a rise in strongyle worm egg counts in recent weeks, with some producers reporting clinical signs consistent with barber's pole infection. The recent warm weather and frequent patchy storm activity have created ideal hatching conditions so we recommend regular worm egg counts over the next few months.
This has also been a particularly bad start to the fly season, with many producers commenting on the high fly numbers. We would recommend careful monitoring of sheep flocks for fly strike, as some producers are already having problems.
There has been a significant increase in the number of worm tests (Worm Egg Count, WEC) being performed in the Wagga area, and rightfully so, given the recent warm weather and unseasonal rainfall. Although dry ewe worm burdens have been averaging 200–400 epg (enough to merit drenching), the majority of the lamb WEC results observed have been yielding quite high results (in excess of 500 epg). It is also important to note that only very few producers have reported any clinical signs: “few animals with scours”.
Advice for producers in the Wagga area at the moment is to consider an early summer drench. Mobs should have 10 individual faecal samples tested for eggs to determine their current requirement for drenching. Calling your private vet or district vet to discuss the results may be valuable in this decision-making.
Addendum: Although it is not the usual time to see barber’s pole worm, as this worm usually only affects sheep mobs in the Wagga area in late summer/ early autumn, there has been one case highly suspicious of barber’s pole worm in the Junee area. Laboratory confirmation is pending. Barber’s pole worm likes the recent warm, wet weather conditions and as one farm is already showing (unconfirmed) infection, barber’s pole is now an important consideration going through the season. Veterinary advisors, such as your private vet or district vet, should be consulted if you require further information.
Looks like Santa will be bringing barber’s pole for Christmas in Inverell. Good general rain in the area has conditions primed. The worm egg counts coming through currently are quite variable within and between tests with some high individual counts, but most averages are unremarkable. Managing paddock contamination now will help to better manage worms into next year.
For the Moree Plains area only seven worm egg counts were submitted! BUT, from all of these good old barber's pole was the offender ranging from 92%–100% of the larval culture. Mean Worm Egg Count (WEC) numbers were 48–1076 epg.
I have also had a couple of conversations with producers regarding weak or dying sheep and advised these producers to drench for barber’s pole if they do nothing else. With recent rain and the warm weather, barber’s pole will be an issue. An email to my list of sheep producers—limited in number —was to remind them to start doing pre- and post-drenching WECs and possibly cultures (as barber’s pole is going to be a potential issue).
Western part of the Murray LLS region
Worm counts at the moment are focused on the 6-month old lambs. The average worm egg count was 680 epg whilst the average *thin necked intestinal worm (Nematodirus) count was only 104 epg. Low numbers of coccidia were also a common factor. The results from the larval culture showed the most common worm present being black scour worm (around 60% of the count) with brown stomach worm and small intestinal worm making up the rest of the count.
*Editor’s note: Thin necked intestinal worm (Nematodirus) can be quite harmful to young lambs. A WEC over 200 epg in young lambs warrants a drench.
Eastern part of Murray LLS
Worm egg counts were again focused on the weaner lamb group with average numbers being lower than those in the west. Average count was 73 epg with Nematodirus being 67 epg. Low levels of coccidia were also present. No tapeworm eggs or segments were seen in the count. The species breakdown was very similar with 60% black scour worms and 40% brown stomach worms.
Several consecutive warm rainy days not only disrupted shearing schedules, but were ideal for hatching of Haemonchus (barber's pole) worm eggs. While no outbreaks of disease due to Haemonchus have been seen yet, some mobs have high worm egg counts that are predominantly barber's pole. Remembering how quickly a few barber's pole worms become a lot, managers of sheep flocks in all parts of the district need to be vigilant.
Apart from high worm egg counts, blood-sucking Haemonchus causes anaemia (check for pale membranes inside the lower eyelids), weakness and sudden death. Several producers have noticed these exact symptoms recently in well-grown un-weaned lambs, about six weeks after marking and mulesing. In one case, a few bigger lambs were found dead in the paddock, while on two other properties, a lamb dropped out during mustering and died when lifted onto the ute. These lambs had "infectious anaemia" (also called Eperythrozoonosis) or M.ovis infection. Several bigger flocks in the district have seen M.ovis for the first time ever, this year. An autopsy confirmed the diagnosis and ruled out Haemonchus. Mustering and handling of lambs affected by M.ovis anaemia often kills them, so it is important to work out early whether the anaemia is due to M.ovis or Haemonchus.
Elsewhere, sheep are carrying significant black scour or brown stomach worm counts. It may be tempting to delay weaning, given the amount of green feed about, but lamb growth rates will be retarded by worm build-up in lambing paddocks. Despite late rain extending the green of spring, it has hayed off enough for a first summer drench.
Blowfly activity has ramped up in response to showers. Any sheep with a few wet dags has been a prime target for breech strike, and winter-drop crossbred lambs are being struck on the shoulders and back. Watch the withholding period on blowfly products, as different restrictions apply to meat and wool. Your treatment of choice may differ, depending on when you intend to sell, or whether you intend to retain and shear some lambs later. Wool withholding periods for blowfly products range from nil to three months. And don't forget a poll treatment for rams. Flystrike on the head is common in fighting rams at this time of year, and may cause the ram to be infertile for two months or more—which is right about the time you wish to join.
Lice: Three new mobile sheep dips have started work in the area this year, bringing the total locally to five. They all report being fairly busy, which is a good indication of how many lousy flocks we have! Take the opportunity before shearing to check any rubbed sheep for lice, to give yourself not only the best chance of finding them, but also allowing the best opportunity for control. You could even consider getting your shearers onside with "sheep lice bingo"; one local producer awards a slab to the first shearer who detects any lice!
With the recent rains across the region, it can be expected that worm burdens will continue to require monitoring. Recent testing has shown Trichostrongylus (black scour worm) to predominate, with an increase in Haemonchus (barber’s pole worm) numbers also occurring; a couple of reports averaged 425 epg and 590 epg respectively.
Producers are reminded to undertake Worm Egg Counts tests (WEC) especially if they are seeing increased scouring amongst their mobs.