Worm-Heat-Map-Latest-April

March is peak barbers pole worm season and this is supported by egg counts from samples submitted during the month. More than 30% of samples from this region had greater than 1000 eggs per gram. Egg counts in March not only indicate the immediate risk and need for treatment, but eggs that develop during this month will be larvae that infect sheep throughout winter and into the spring. With the amount of rainfall that fell across the region during March, eggs will have seen enough moisture and had the right temperature to develop into infective L3.

In the west of the region, the average WEC has decreased since the last report reducing to 350 epg. The majority of counts were less than 250 epg, indicating that treatment for most sheep classes was not warranted. However, in the east of the region a very different level of challenge was found, with most of the 255 samples from the region returned a result above 1000 epg. As for the northern NSW region, eggs that develop in this season will cause infections throughout winter and spring.

The rainfall event in mid January did not appear to make WECs jump in March, but follow up rainfall events in March make worm testing an important tool throughout April. The average WEC in the east was 443 epg, significantly higher than the western region with an average WEC of 143 epg.

The continued dry weather in Western Victoria continues to supress worm burdens, with all of western Victoria shown as green. For those wanting to see a good summary of climate models predicting seasonal climate, The Fast Break – Victoria is a great resource. The summary is “assessment of 12 climate models for Victoria is neutral for rainfall (plan for anything)”.

The east of the state has seen above average rainfall, and this is reflected by greater worm challenge. The average WEC in the Gippsland region was above 500 epg, and in the north-east, was 210 epg.

In the south-east of the state, worm burdens have lowered from their peaks in February, but remain high for this time of year.  While it remains dry, the large number of high counts shows that worm burdens should be monitored. More samples are also showing Nematodirus eggs which are well equipped to survive drought. Be wary of this species when rainfall does occur as treatment thresholds are much lower for this worm species compared to other common worms.

Some selected parts of Western Australia had rainfall in March, and regions with samples submitted indicate higher worm burdens than the previous month. The southern region had an average WEC of 433 epg, while the central region fell into the category below. For most sheep, the drench threshold before the autumn break is 200 epg in these regions.

The average WEC in in eastern Tasmania rose in March, with the region now shown as yellow. The average WEC for the region was 300 epg, with 40% of samples submitted indicating that a treatment was required for the sampled mob. 

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-April