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South Australia worms, flies and lice update - April 2019

SA WormBoss Worm Control Programs

SA WormBoss Drench Decision Guides





Weather records continue to be broken with Adelaide’s 17.8 mm rain up to late April for 2019 being the lowest rainfall recording in 133 years. The average is 108 mm for the same period. Most of the State has endured a similar rain scarcity, and this appears to have also impacted sheep worm burdens.

Recent worm egg counts (WEC) have been remarkably low with only the occasional weaner report hitting triple figures. The dusty brown landscape is not hospitable for any parasite, and remaining stock are surviving on full supplement feeding in most areas. Even WECs from the south-east mostly range from 0–100 eggs per gram. Many stock are being grazed in confinement areas and provided they were monitored and/or drenched upon introduction worms are unlikely to be a cause of concern. Pre-lambing drenching would only be indicated if WECs are high or average body condition is less than 3.

The weather forecast to September based on El Niño and warm sea surface temperatures to the north is not encouraging but tends to be unreliable due to the unpredictability of cold fronts from the west. Dry sowing has commenced in the hope of significant rain in May…fingers crossed. In the meantime, worm burdens are unlikely to change until a green pick emerges. Monitoring should commence 3 weeks later to see the impact of early germination.

Body condition scoring is the best assessment of the feeding regime whether on full supplementation or feed in the paddock. This is especially the case in the lead up to lambing where hay alone has insufficient energy to meet the needs of the late pregnant ewe. The scarcity of hay has meant poor quality hay is being sold for exorbitant prices, i.e. $250–350 / tonne and usually without a feed test. This has led to a significant loss of condition and stock deaths in some instances. Barley grain introduced and increased over 3 weeks, and with a 10–15% legume inclusion for late pregnant and lactating ewes is the only answer to meet their energy and protein needs. Adlib calcium and salt mix is also recommended to avoid milk fever due to the relatively low calcium in grain diets.

Flies are unlikely to have caused many issues with the exceptional dry period, but lice numbers will be starting to rise with the onset of winter. It is useful biosecurity to check 10–20 sheep for lice when they are in the yards along with condition scoring 30–50 to monitor their health. Here’s hoping the season is better than the vague forecast!

For April 2019 state outlooks, please follow the links below:
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