NSW WormBoss Worm Control Programs
NSW WormBoss Drench Decision Guides
Strongyle-type worm egg counts ranging from 16–2208 eggs per gram were reported from submissions for worm testing this month. Very few cultures were run, and of those that were, a few had low numbers of thin-necked intestinal worm.
Editor’s note: immature Nematodirus in the small intestine cause more damage to the intestinal lining than do the adults.
Coonabarabran received 40+ mm of rainfall during November, and 25 mm in early December. This brought some moisture, and pasture growth. Regular monitoring using a WormTest (with culture) is recommended during this summer period, particularly if rainfalls continue.
The few worm tests from EMAI in the last month have reported strongyle-type egg counts in the thousands on some properties in the Coonamble district.
By contrast, on other properties where producers have worm tested frequently, drenched strategically and used paddock rotations as part of their parasite management, the worm levels are still low.
The message for now is if you are unsure or haven't tested lately, do a WormTest.
The worm outlook from here really depends on the frequency of summer rains. If we don't get rain and the heat continues, worm levels will remain generally low across the district, however if we experience storms across Christmas and into January we could see barber’s pole worm infections become clinical disease.
Don't get caught out—monitor your flock by worm testing regularly.
On the cattle scene, some of the district is still very dry and cattle are continuing to be supplementary fed. Ostertagia sp. burdens have been seen in nutritionally stressed cattle and a drench is warranted in these animals.
Few worm tests have been submitted for the Forbes area, and the few that have, showed varied results.
The advice continuing into summer is to conduct worm tests (WormTest) prior to drenching to help determine whether that drench is required. Young, undrenched sheep are at greatest risk, and subclinical worm burdens can be a cause of production loss. While we experienced a dry winter, these late spring storms mean that barber’s pole worm could be a concern.
For this region, the main issue continuing into summer is going to be barber’s pole. The numbers seen in worm testing are indicating this and also reflecting the very favourable conditions experienced over the past 3 months—mild and wet. It will also depend a bit on the coming summer; if we get rain and temperatures don't peak too much—though it is 38° today and getting to 40° over the weekend—barber’s pole numbers will increase.
Editor’s note: at 35°C, barber’s pole larval survival rates on pasture start to decrease, and over 40°C, most die rapidly.
We have also seen some high black scour (Trichostronglus spp) worm numbers but I think this has been due to egg survival over the mild winter followed by favourable spring conditions.
Producers have been warned about a big parasite year if they don't get on to it immediately, and start checking with WormTests. Only time will tell how many heeded the warning. With sheep being worth quite a lot now, it is even more value for money to test, especially with pre- and post-drench worm egg counts (DrenchCheck) for drenches.
West Murray region
Several worm tests (WormTests) performed in the West of the region revealed low worm burdens in most mobs, and some very high burdens in a few mobs. Mortalities due to barber’s pole were confirmed on one property and suspected on another two properties. All mobs responded to drenching. These infections are consistent with a wetter than average December and most sheep will now carry low numbers of worms into summer, if not drenched. Some paddocks, typically those with sandy soil with short, green pasture create ideal conditions for barber’s pole worm to rapidly multiply resulting in high burdens and clinical cases.
East Murray region
Sheep WormTest submissions from this part of the region have been trickling in, with results showing quite variable worm burdens. Landmark Albury is currently concluding a pilot drench resistance and efficacy project funded by the Australian Government National Landcare program. Latest data from the project also recorded variable WormTest findings, with a number of mobs showing evidence of significantly high worm burdens. Two mobs recorded average worm counts of 1062 eggs per gram (epg) and 977 epg with larval differentiation indicating 94% and 98% barber’s pole worm, respectively. Whilst we haven’t yet seen an influx of clinical cases here in the East, barber’s pole worm will remain a high risk as sporadic summer rains and warm conditions are persisting.
Sheep producers should continue to carry out regular WormTests on all mobs in order to detect problems early. A little monitoring will go a long way in avoiding worm issues over the busy festive season.
Feliz Navidad! https://www.youtube.com/watch?v=RTtc2pM1boE
Just when everyone else is thinking about having a breather, many sheep producers in this area will be kept busy by blowflies and barber’s pole worms. Late spring rain followed by showery weather and a few storms have produced conditions ideal for both these deadly parasites.
Alas, some who have not read the signs and have headed to the beach may be disappointed on their return.
Deaths from barber's pole worms have occurred in a couple of better-managed flocks. In one case, the ewes had been drenched at lamb marking five weeks ago, when the mob was moved to a spelled paddock. The mob was yarded for the lambs to be drenched only a week ago, and no problems were apparent. A week later, three pretty fat ewes dropped dead while moving the mob a short distance, and several ewes were noticed to have bottle jaw. The dead ewes were extremely pale, and masses of adult Haemonchus were seen on post mortem examination. Dung samples collected from the drenched lambs had worm egg counts exceeding 4,000 eggs per gram, indicating the drench used a week prior was ineffective. This case is a reminder that barber's pole worms are increasingly being found resistant to drenches. The drench used on the lambs contained only abamectin, a chemical which now fails to control Haemonchus on more than 50% of properties in our area.
(Editor’s note: Drench-resistant barber’s pole worm are the norm in northern NSW)
In another case, the absentee owner noticed one sheep "a bit sick" when he visited on the weekend. By the following Friday, six of his forty fat crossbred hoggets had died in the paddock. They had plenty of feed, and had been drenched with ivermectin five weeks previously. In a third case, six of a mob of seventy does with young kids died four weeks after a drench. Unfortunately there are few registered drench options for goats, and there is widespread resistance by barber's pole worms to these drenches.
Of course possible drench resistance is not the only explanation; barber's pole worms lay stacks of eggs that hatch quickly when it is warm and wet enough, leading to heavy pasture contamination. Sheep and goats can pick up a fatal burden of barber’s pole (Haemonchus sp) soon after drenching with a short-acting drench, if left to graze a dirty pasture.
NB: it pays to check that the drench you used has worked, by a DrenchCheck test 14 days after drenching.
Any wet dags on the back end of sheep, particularly crossbred lambs, are a target for breech strike at present. It doesn't take much to get it started, and only a couple of days more for things to become critical. The cause of scouring should also be determined. The scouring that attracts the blowies has often been feed-related, associated with a range of different plant species. A few cases have had significant levels of black scour worms or brown stomach worms contributing, especially if weaning has been delayed, or lambs have been weaned back onto lambing paddocks to avoid grass seeds.
Barber’s pole worm continues to be the biggest concern at this time of year, but drier conditions in some areas have reduced the risk somewhat. Summer storms can be quite localised, so pasture moisture (and therefore rates of barber's pole hatching) will vary across the district. Producers with high stocking rates should be especially watchful, and are advised to use a WormTest kit to identify worm burdens early. Of the few WormTests performed by producers in the Greater Sydney region in the past month, most have revealed low egg counts.
However, barber's pole was a factor in a recent case of multiple deaths in a goat herd.
There weren’t any samples submitted for faecal worm egg counts (WormTests) in the Western division in the past month.
We encourage landholders to monitor for increases in worm burdens as the bit of rain we received will make conditions suitable for survival of free-living larval worms on pasture and numbers to build in sheep.