Worm-Heat-Map-Latest-February

Worm infections remained extremely high in February with average WECs being greater than 1000 epg across the region. Vigilance is required to ensure sheep are treated in time before clinical signs of infection, such as lethargy, anaemia and death are noticed.  March is the time to take action to ensure that spring lambing paddocks have no sheep worm eggs deposited on them during autumn. The combination of grazing management in autumn followed by the climatic changes in winter prevents pasture contamination that will be the source of worm challenge for ewes and lambs later in the year.

In the west of the region, the average WEC was 996 epg. Some very high counts were returned to reach this figure as half of the samples had a WEC <250 epg. In the east of the region, the average WEC for the month was 742 epg with 22% of samples above 1000 epg. These counts strongly suggest that barber’s pole worm is the major concern at this time of the year.

In this region, several DrenchChecks have also been carried out to assess drench efficacy. Performing a DrenchCheck 10-14 days after treatment is a cheap and convenient tool to ensure the drench is working as expected. 

Most of the south-western slopes region experienced greater than average rainfall for the month of February with the average WEC for the region above 400 epg. To the west of the region, the average WEC was slightly lower, correlated to the lower rainfall. Worm testing in this region is important 4-6 weeks after significant rainfall events, especially when there have been subsequent rainfall events. Treatment thresholds are based on stock classes and type of worm challenge (see Wormboss Drench Decision Guide). Getting a larval culture to support a WEC at this time of year will help determine if you can use a low treatment threshold (less than 60% barber’s pole worm) or higher treatment threshold (>60% barber’s pole worm). 

With the new map colour and categories, all of Victoria is free of any red that indicated a very high risk of worm challenge. That might make farmers in the central and western districts feel like the limited rainfall is at least making it tough for parasites too. While the vast majority of samples have returned a low WEC (40% 0 epg, 42% <250 epg) several samples have returned very high counts for this region.  Remember to sample 4-6 weeks after the autumn break to keep worms under control.

In the south-east of the state, worm burdens continue to remain high with the average WEC above 600 epg. Many high counts are being returned despite extremely low rainfall in the region. If sheep are grazing irrigation, be wary of barber’s pole worm successfully developing in this climate. Across the region, WormTest at 6-8 weeks intervals until pre-lambing and treat if counts are > 200 epg in late summer/early autumn. 

Across Western Australia, the worm challenge has reduced in February compared to January. On the Esperance Plains, the intensity has decreased to green, signaling low worm challenge. Most counts returned were below 250 epg. Keep worm testing, especially 6 weeks after the autumn break, and treat if the WEC exceeds 300 epg.

More samples were submitted from Tasmania in February which is great to see. The limited rainfall over the past two months has kept worm challenge low in eastern Tasmania. Continue testing at regular intervals, treatment thresholds for weaners in Tasmania range from 200 to 300 epg.

We hope you find these updates valuable.  Let us know what else you would like to see. And get those samples submitted!

Rainfall-Map-Latest-February