NSW WormBoss Worm Control Programs
NSW WormBoss Drench Decision Guides
Sporadic storms have fallen across the Coonamble district, however the chronically dry ground has grown little pasture and the district remains largely drought affected. Stock numbers are reduced and almost all remaining stock are being supplementary fed. Worm egg counts are universally low, although producers are reminded to keep testing into summer if storm activity continues, as it is expected that barber’s pole worm burdens will increase rapidly if the conditions improve.
Flystrike is a major issue in many flocks. This is due to a number of factors including sheep that were not mulesed this year due to lamb or weaner health and strength concerns, dag formation due to high grain diets, green pick or infectious scours, and the recent storm activity. Because the issue is multifactorial, producers are urged to use a multi-faceted approach to prevention and treatment, and the FlyBoss website is an excellent resource to help with this.
It is important to not just rely on chemicals. Producers have reported that some preventative chemicals are not working effectively, and we are encouraging producers to submit maggots for free resistance testing. Producers are also reminded that the problem may not necessarily be resistance; dosing and application are very important to product efficacy, so read the label and take care when applying any products.
Fly worry is also affecting cattle herds with high incidences of pink eye in stock, especially early weaned animals. Appropriate treatment, fly prevention, environmental changes to reduce dust, and appropriate nutrition are all recommended for stock with pink eye. Producers should also consider vaccination for pink eye; this could be something to discuss with your private or district veterinarian.
Sporadic storms in the Forbes area of the Central West LLS have resulted in sporadic pasture growth and some 'patches' look good. With ongoing rain, barber’s pole numbers will increase rapidly and a single female worm can lay up to 10 000 eggs per day. In the right conditions (moisture and warmth), these eggs rapidly hatch and develop into infective larvae ready for ingestion by sheep. Regular worm testing should be used to monitor worm infestations. However, on rare occasions sheep can become infected with large numbers of larvae at the one time and the infestation can result in clinical signs for a short time before these worms reach maturity and start producing eggs. If mustering coincides with such a time sheep may go down or lag behind and it’s worth catching them and checking the colour of the mucous membranes of the inside of the lower eyelids - if it is pale, barber’s pole worm may be an issue (occasionally Mycoplasma ovis may be the cause of anaemia—see the report below from Mark Corrigan and Eve Hall, and in high rainfall areas liver fluke can cause anaemia).
Fly strike is also increasing in incidence due to increased warmth, moisture and humidity. Producers are advised to act early and develop an integrated pest management plan to not only protect their sheep from strike, but to prevent fly numbers building up over summer. If you do have struck sheep and wish to check how the chemicals are working on your place let the district veterinarian in your area know. We can collect some maggots and send them away for testing. (More information on collecting and sending maggots).
In the Young end of the Riverina LLS (northern), we have had ten worm egg count tests performed in the past month. The majority of these tests have been on ewe mobs in medium to good condition and with their lambs weaned. While overall the worm counts have been low to moderate (300 eggs per gram (epg) was the highest average count), there has been quite a lot of variability within mobs when individual counts were performed, with some individuals as high as 680 epg. A few larval cultures have also been done and typically, mixed populations of all three major players were present—Haemonchus (barber’s pole worm), Trichostrongylus (black scour worm) and Teladorsagia (brown stomach worm). The dominant population seen was Trichostrongylus spp, which accounted for 56%, 87% and 74% of the population in the three tests performed with larval cultures.
For our region, the "first summer drench" is coming up and if we use these ten flocks as a barometer (6/10 being above 200 epg average), a recommendation would be to monitor your flock prior to drenching, and also to re-evaluate any previous worm control measures implemented on your farm! This is especially true if conditions remain towards the dry side as worm populations and activity will usually be lower.
For specific discussions around your farm’s worm control options, the district veterinarians in the region are more than happy to discuss them with you.
In the Griffith end of the Riverina LLS we have had a handful of worm egg count tests performed in the last month. Strongyle burdens have been very low in sheep (highest average count 80 eggs per gram (epg)) and in cattle (average 60 epg) across varying classes of livestock. However, given the recent warm weather and scattered rainfall events, we recommend regular worm egg counts over the next few months.
There has been little worm activity over the last month. Some worm count results from Moree and further west were low. It's raining today so maybe that might be the start of something.
In the east, seasonal conditions remain variable. Sporadic and isolated rain events continue. WormTest results over the past month have shown moderate worm egg counts of around 200–460 eggs per gram (epg) in submissions from various ewe mobs.
There have been no reports of worm related disease, however we have seen a number of properties impacted by Mycoplasma ovis, a bacterial disease that affects red blood cells and results in weakness, anaemia and death. It can be spread by mosquitos and other insects. Mycoplasma ovis infection can look very similar to barber’s pole worm infestation, as they both cause anaemia. The best way to differentiate the two is to do a low-stress paddock worm egg count (i.e. collecting freshly-passed samples from the pasture). There is no treatment for Mycoplasma ovis, but time and minimising stress will see affected sheep recover and develop some immunity. Avoid any yarding and unnecessary drenching as this can trigger losses.
With moisture and warmth associated with current conditions, producers should continue with WormTests on ewe mobs to monitor for rising worm burdens and utilise larval cultures to get an idea of what type of worms are about.
Producers who are feedlotting lambs should be keeping an eye out for signs of coccidiosis—mainly dark scour and ill thrift. Coccidiosis can be brought on by confinement, stress and poor immune systems. Early weaned lambs are especially at risk.
Rain has been very patchy with falls ranging from less than 15 mm to over 40 mm. Daily temperatures are climbing with the highest daily maximum reaching the 30s. The region has generally greened up, but some parts are already haying off. Pasture height is short.
On properties where grazing management plans have not been compromised by the drought pressure, worm counts are very low and drenching has not been required. However, in situations where the provision of clean pastures has not been possible, counts are on the rise with worm numbers approaching a level that requires drenching. This has been particularly true for some of the bigger enterprises. Barber’s pole worm, black scour worm and brown stomach worm are all in the mix, with significant variation between properties.
Considering the variation in rainfall and pasture management from property to property, some may find they don’t need to drench, while others who assume worms are not active might get a nasty surprise. Use a WormTest to make an informed decision.
The last four weeks have seen a swift transformation from spring into early summer with most areas drying off without a lot of spare dry feed. With the average daily temperatures on the increase and a little bit of rain around from storms, internal parasites are likely to become active in areas that have had relatively more moisture.This is particularly a problem if sheep are grazing short green pick and if barber’s pole worm is present on the property.
On the other hand, hot dry winds are probably helping to keep worm numbers at bay. Lambs are being drenched at weaning and producers are preparing for the first summer drench to be given as pastures dry off at the beginning of summer. Worm counts have remained at low to moderate levels, but are very variable, reflecting differing management and the benefit of testing on your own property.
The tough seasonal conditions are presumed to have contributed to higher lice numbers in cattle (sometimes associated with nutritional stress), and higher lice counts have also been seen in sheep. With stock in closer contact during trail feeding or confinement feeding there has been more opportunity for lice to spread within a mob.
Blood tests have also confirmed fluke as a cause in a couple of cases of ill thrift in cattle.
Your best tool to ensure you stay on top of worms and learn what is happening on your farm is worm egg count monitoring (WormTests). Kits can be obtained straight from EMAI or picked up from your local LLS office or your local rural merchandising store.