NSW WormBoss Worm Control Programs
NSW WormBoss Drench Decision Guides
Weather remains hot and dry with little to no ground cover and stock are still being entirely hand fed. Worm burdens remain very low and drenching is unwarranted in the majority of situations.
There have been multiple cases of coccidia in early-weaned lambs in the last week, presumably brought on by confinement, stress, faecal-oral contamination and poor immune systems.
Early pregnancy testing results in cattle are sub-optimal (40–60% in calf is commonly found), and producers are advised that in order to give cattle every chance of conceiving this year they need to concentrate on putting stock on a rising plane of nutrition. A drench for adult cattle (and weaners) is still recommended due to larval Ostertagia burdens occupying the abomasum in drought-affected stock. This will help them gain condition and make the best of available nutrition.
Storms have been sporadic around the Forbes area with some big once–off isolated rain events whilst others have missed out. Larvae may be surviving on paddocks in some of these wetter areas, particularly if occasional storms continue and pastures start to grow. Producers should WormTest before considering a first summer drench.
Blowflies are beginning to increase in number with reports of struck sheep. Producers should develop an integrated pest management plan to minimise the impact on production and reduce the build-up of fly numbers.
Worm wise, counts in the Riverina have been variable, and very dependent on individual farm management and weather events. With the warmer weather and weaning approaching, a weaning drench with an effective drench type is recommended for all flocks. Testing (WormTest) ewe mobs for levels of worm burden prior to drenching would also provide good information. In addition, this time of year is always good for checking worm types by requesting larval cultures. Also, if you are about to use a different drench type, then doing a pre– and 14-day post-drench egg count (DrenchCheck) can provide valuable information on how that particular class of drench is performing on your property.
There haven’t been many worm egg counts yet, but the recent rainfall, particularly on the western side of the Northern Tablelands, followed by the warmer weather is setting up nicely for a late spring with plenty of barber’s pole worm infective larvae on paddocks.
Most ewes are still ‘back’ in condition and they will be highly susceptible to these increases in worm larvae numbers on pastures.
In the east, conditions vary somewhat with most areas experiencing far below average rainfall, and negligible ground cover. Conditions improve closer to the Hume Highway, and further east the ‘partial’ season is hanging on with the help of some rains from sporadic thunderstorms experienced over the past 2–3 weeks.
WormTest results from the eastern part of the region over the past month have shown low to moderate worm egg counts (0–200 strongyle type eggs per gram (epg)), although the short green pick in response to recent rains, and warmth may lead to more serious issues. In a mob of Merino ewes with some scour, weight loss and the occasional death, a WormTest showed an average of 336 strongyle type epg, of which 99% were black scour worm. These ewes were last drenched with a moxidectin pre–lambing in March 2018. Based on the worm egg count alone and faced with dying ewes, the producer opted to drench with a combination drench containing abamectin, albendazole, closantel and levamisole. The ewes responded positively and no further deaths have been observed.
WormTest results for the western part of the region have mostly shown minimal worm issues. The only significant result was from weaner lambs with an unknown drench history, and an average faecal worm egg count of 2080 epg strongyle type and 80 epg nematodirus type. The strongyle breakdown was 81% barber's pole worm, 17% black scour worm and 2% brown stomach worm.
Many producers this month have been conducting worm counts (WormTests) on their yearling hoggets as these sheep have been on short green pick and under some nutritional stress.
Monitoring has been valuable to see if these sheep can make it to the first summer drench without needing a drench, but the results have been variable. Worm egg count numbers have not hit the level to trigger a drench in most cases even though the counts have contained a significant proportion of barber’s pole worm showing that the continued monthly monitoring of egg counts or the strategic use of long acting drenches such as closantel, have been of value.
Significant numbers of individual worm counts have been conducted on alpacas this month and most results have been very low indicating that no drench was required and showing the benefit of testing rather than drenching routinely.
Large numbers of individual horses have also been tested and many of these have returned very high counts despite a relatively recent drench, again showing the benefit of testing.
Some cattle have shown a positive result for fluke using the ELISA blood test. This test is more accurate than a faecal fluke egg sedimentation test. The positive test result allowed the producer to make an important strategic decision to drench the whole cattle mob to greatly reduce fluke numbers and the resultant problems over the summer.
Your best tool to ensure you stay on top of worms and learn about what is happening on your property is to undertake regular faecal egg count monitoring. Kits can be obtained straight from EMAI, or picked up from your local LLS office, or your local rural merchandising store.
Egg counts in the Mudgee district in recent weeks have been variable. In some cases, sheep thought by producers to be particularly "wormy", had low egg counts—this highlights the value of performing a WormTest before deciding to drench.
Reducing unnecessary drenching will delay the development of drench resistance. Regular rainfall and warm temperatures are beginning to create ideal conditions for the hatching of barber's pole eggs on pasture. Sheep that have been confined for feeding at higher than normal stocking rates may be particularly at risk, due to exposure to increasingly contaminated pastures. Drenching sheep at weaning is likely to be of benefit. For other stock, a WormTest is the best way to decide whether to drench. Your District Veterinarian is available to discuss egg count results with you.
Some worm tests have been done as part of mortality investigations. As expected, faecal Worm Egg Counts (WEC) have been mostly zero and drought related issues (stress/malnutrition/acidosis etc) are implicated in the deaths of stock. Some coccidia have been identified in feedlotted lambs