NSW WormBoss Worm Control Programs
NSW WormBoss Drench Decision Guides
The majority of the Coonamble district received welcome rain in significant quantities in recent weeks with 50–100 mm falling. True to the adage "it doesn't rain feed", pasture growth has been very slow, and follow-up rain is needed to convert the moisture into useable stock feed coming into winter. Despite the rain, worm egg counts remain low around the Coonamble area. Producers are, however, reminded to continue to WormTest if there is follow-up rainfall as the weather remains warm and Haemonchus contortus (barber’s pole worms) will be hatching and developing into infective larvae.
Recent worm tests on early weaned calves run in confinement yards for the past 4–6 months, have all been low indicating that these yards are a good example of a well-run early weaning set-up in which calves receive adequate nutrition that is fed up off the ground to restrict faecal-oral larval contamination.
Fly burdens are moderate following the recent rain and continued warm, autumn temperatures. These weather conditions have resulted in struck sheep from blowflies, but also pink eye in cattle transmitted by small black flies. Producers are urged to monitor stock regularly (every 2 days or more frequently) and treat affected animals.
Things are still quiet on the worm front in the Forbes district. Based on the worm egg counts we have been seeing, it would be advised NOT to drench sheep without first conducting worm tests. Counts on samples submitted, in general, have been low, and in these instances, drenching could increase the rate of resistance developing on your property. Using test kits to monitor the most susceptible stock (young sheep and pregnant ewes) would be a sensible approach, and we have a great supply of them here in our Forbes office if you would like to stop by and pick some up.
Overall, the worm burdens in the Young area seem to be relatively low. The dominant species in the worm egg count tests has been Haemonchus contortus (barber’s pole worm). There has been the odd case of heavy Nematodirus spp (thin-necked intestinal worm) burdens in young ewe lambs following the rain and mild temperatures. While the counts have been in the low to moderate range (200–400 eggs per gram), they were still high enough to impact production and were worthwhile drenching.
Leading up to autumn lambing, producers should consider carrying out a worm egg count test (WormTest) to monitor worm activity on-farm or to determine the need for the pre-lambing drench. Now is an ideal time to start locking up weaning paddocks (or put cattle in them instead) so that the pastures become low worm-risk and ideal for freshly weaned lambs that will have poorly developed immunity and ability to deal with worms, and to ensure they become as productive as possible.
In the southern Riverina around Wagga Wagga, many producers have finished pregnancy scanning and are fast approaching preparation of ewes for lambing. Immunity temporarily declines in ewes at lambing and lactation and makes them more susceptible to the effects of a worm burden. Around Wagga in the last month, strongyle worm egg counts have ranged from an average of 140–440 eggs per gram with Trichostrongylus spp (black scour worm) being predominant in the larval cultures. Counts in this range indicate that ewes will benefit from money being spent on a pre-lambing drench. Pre-lambing is the ideal time to complete inexpensive worm egg count testing (using a WormTest) and a larval culture to determine if there is a worm burden present, and if so, which drench will be effective. Technical support through the process of collection, submission and interpretation of results is available—call your local District Veterinarian.
Few worm egg count tests have been submitted from the western Riverina region over the past month. Currently, most producers are hand feeding ewes that are in either late gestation or on the point of lamb. Many producers have had ewes in containment areas for prolonged periods and plan to move them into larger paddocks just prior to lambing. It is recommended to do pre-lamb WormTests to determine the worm burden of the flock, especially as some high WormTest numbers have been reported from confinement-fed mobs since the start of the year. You can call your local District Veterinarian to discuss your situation.
Currently, most of the producer concerns about sheep health-related issues are around feeding grains:
There has also been an increase in animal welfare related activities in association with animal welfare enforcement agencies.
Still not a worm test in sight up here. Nothing all year.
One day it will rain again, and cool down (maybe), and worms may once again cause us problems. For the moment, I'm appreciating any small blessings and am grateful that the worms seem to be suffering in the drought as much as the rest of us.
Most areas around the local region have received rain ranging from 90 mm to 128 mm in March. The March rainfall recorded at Braidwood was 92.2 mm, which exceeded the average rainfall here by almost 50 mm. This rain has resulted in much-needed autumn pasture growth. It is recommended that producers assess their pastures and set aside lambing and weaning paddocks, and keep sheep locked out for the next four months. This approach will give every opportunity for pasture growth to occur as well as to prepare them as low-risk for worms.
Conditions through March and up to the start of April were moist and warm enough to allow eggs of Trichostrongylus spp (black scour worm), Teladorsagia sp (brown stomach worm) and Haemonchus contortus (barber’s pole worm) to hatch and develop into infective larvae. The Bureau of Meteorology is predicting warmer than average days and nights for April to June, so the hatching period for barber’s pole may continue through May this year. Worm tests show barber’s pole is currently the predominant worm affecting sheep in the local area.
Autumn in our region is typically a time for a fluke drench, and many farmers use the adage, “after the first frost”. The thinking behind this strategy is to “empty out” the fluke from stock before the winter hibernation of the carrier snail. In theory, the stock then do not pick up fluke again until the spring.
Some producers may want to make modifications to their usual approach this year. On the one hand, as temperatures are likely to stay warmer than average for the next couple of months, a “first frost” may not indicate the setting-in of cold weather and stock may be at risk of continuing to pick up fluke after the autumn drench. On the other hand, stock that were forced to graze flukey areas during summer may have substantial fluke burdens and could develop symptoms if producers hold off on the autumn drench until colder weather sets in.
If you are unsure, monitor carefully for signs of fluke such as pale eyes and gums, bottle-jaw, ill-thrift or unexplained deaths, and talk to your advisor about testing for fluke with either faecal egg counts or blood tests. Also, don’t forget that the autumn drench needs to be one that is effective against early immature fluke, so it should contain triclabendazole.
Worm egg counts have been variable in the Shoalhaven and surrounding areas. Some flocks are showing zero to low average worm egg counts in WormTests while others are showing medium to high average worm egg counts. Contributing factors appear to be a combination of contaminated paddocks, good larval survival on pastures, animals grazing available short green pastures, and recent falls of rain. Producers are encouraged to revisit strategies for creating low worm-risk paddocks and testing various sheep mobs with a WormTest. Worm testing is especially important as some producers are currently weaning and others are preparing for lambing this autumn and going into winter.