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Tasmania worms, flies and lice update - March 2017

Tasmania WormBoss Worm Control Programs

Tasmania WormBoss Drench Decision Guides





Perth: Paul Nilon, Nilon Farm Health (pandonilon@bigpond.com)

The season has gone dry,  very dry. There has been no substantial rain for well over 2 months now, although most northern areas received between 3 and 10 mm last week. This will be enough to kick-start a monumental ryegrass staggers season, but little else. Irrigators, largely stored for the cash-cropping season in spring and summer are now going flat-out as producers scramble to rejuvenate wilting fodder crops and start new ones sown in recently harvested paddocks. Good news is that March delivered us the hitherto absent summer with many days in the high twenties and no infernal wind.

WECs (worm egg counts) from lambs on most pastures, but particularly irrigated grass pastures, are on the up and up. No surprise. It is cool enough and there is moisture and cover. Remember the triggers that have been given endlessly (find these in the Drench Decision Guide­—see link at top of page).

WECs from adult dry sheep on perennial pastures are generally very good. The dry autumn has extended the chance to complete a second summer drench, so if you have not given one do so. Pronto. Avanti. (The lapse into Italian is due to the discovery that an old flame is teaching history at an Italian university where our eldest son’s girlfriend is studying. That’s a good reason, yeah?).

A client asked me the value of a premating drench. The reply, of course, is that if he has worms his partner would appreciate his attention to hygiene. So, if the ewes are wormy, or if mating coincides with the second summer drench, then drench away. However, most joinings in Tasmania are too late for a summer drench, or occur in mobs where the ewes are not on perennial pastures. So generally, the answer is no. Rams, by all means; they need all the help they can get.

More worrying are reports of Haemonchus on irrigated pastures. There have been a few deaths, but mostly just high egg counts with sheep doing poorly. Fluke is the main differential as irrigated pastures may also support fluke if there are drains returning runoff to the watercourses. We expect both parasites to peak in March and April. More on this next month.

Finally, while it’s not my role to sell products there are two new ones to announce. Napfix® (Jurox) has returned to the market and should be available in Tasmania by late April. It is a combination of organophosphate (OP) (naphthalaphos), abamectin and albendazole. This is the only OP combination on the market, and will be very useful as an alternative to the usual 3-way combination. It has an ESI of 28 days. Please read the label carefully and observe all embargos to ensure both human and sheep health and safety.

Zolvix Plus™ (Elanco) is a combination of monepantel and abamectin. This should make a potent product more robust. The ESI has been reduced to 84 days (c.f. >115days for Zolvix). There is no good reason to use Zolvix in preference to Zolvix Plus, save for using up existing stocks, and to include monepantel in drench tests, or if drenching concurrently with another product that already has abamectin, moxidectin, or ivermectin.

Monepantel—the active in Zolvix—is a versatile drug. It helps prevent weight loss in parasitised lambs, and the accoutrements help prevent weight gain in middle-aged vets.