Victoria worms, flies and lice update - January 2020

Hamilton: Andrew Whale, Livestock Logic (a.whale@livestocklogic.com.au) and Lexie Leonard, Livestock Logic (l.leonard@livestocklogic.com.au)

Livestock Logic Key Recommendations:

• Continue to closely monitor weaners on pasture
• Worm egg count the ewes and ram soon to be joined
• Drench weaners into containment zones to ensure worm burdens remain low
• Producers can take advantage of high egg counts in weaner mobs to conduct a drench resistance trial if one has not been done on-property in the last 3 years. 

The start of the year has seen the weather a bit all over the place with no long periods of dry, hot weather to help remove worm burdens from paddocks. There is a lot of dry feed around which will also keep worm burdens on paddocks relatively high over summer. Quality of dry feed is generally lower than anticipated, so feed testing is highly recommended. Most mobs will require supplementary feeding to reach nutrition targets, especially mobs being joined.

As was the case last summer, relatively mild weather has promoted the survival of larvae on pasture and we have been seeing an increase in the number of both mature and young stock requiring drenching in January. 

Weather conditions over December and January have not given us a clear cut timing for summer drenching, and we are seeing this now with mobs having very high worm egg counts well into summer. Of more concern is the number of mobs that are requiring re-drenching, 4–5 weeks after being drenched. Continual monitoring of mob worm egg counts over summer is very important to ensure sharp increases in worm burdens do not occur following rain events, and if they do, they can be dealt with efficiently. 

If you haven’t egg counted mobs since the start of December, we highly recommend doing so now. Monitoring weaner mobs closely can also present an opportunity to conduct a drench resistance trial if there is a suitable mob with a high egg count (>300 eggs per gram (epg)).

Flystrike, overall, has not been a major issue so far this season. If temperatures increase again, risk will increase in susceptible mobs—mainly weaners and daggy sheep.