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Quick quiz: 2015 May

The quiz questions are taken from:

The online learning pages focus on the important topics within worms, flies and lice and offer two approaches to learning: structured reading and question and answer.

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Answers and links to further information are provided below the image.

Questions

1. How long do infective worm larvae live?

2. What is the correct length to which tails should be docked, and why is this important?

3. Why is it important to know the group of a lice pesticide?


Answers

1. How long do infective worm larvae live?

Infective larvae are relatively tough and can withstand dry, cold and moderately hot conditions. All populations of living things vary in their life expectancy and worms are no different; some larvae will die within days, but some will live to around a year or more. Generally, over 90% of larvae will be dead within 6 months under cooler conditions and as little as 3 months when temperatures are ideal (about 25–30°C). Under extremely hot, dry conditions larvae will be desiccated and can die in a few days to weeks of these conditions, explaining why worms are rarely a problem in the arid zone.

2. What is the correct length to which tails should be docked, and why is this important?

Docking the tail to the correct length at lamb marking time is crucial in minimising stain around the breech and reducing flystrike risk throughout the sheep’s life.

The recommendation is to dock the tail immediately below the third palpable joint or to the tip of the vulva in ewes.

This tail length allows the sheep to lift its tail and channel urine and faeces away from the breech area. It also reduces the risk of cancers from exposure of soft tissue to the sun.

3. Why is it important to know the group of a lice pesticide?

Knowing which chemical group your lice control products belong to is critical to resistance management—the group is the class of chemical to which the particular active ingredient belongs.

Remember that treatments to prevent flystrike also expose any lice present to chemicals. It is important to use products from different chemical groups when treating for flystrike and lice in the same year and to consider flystrike chemicals when determining a resistance management plan. Fortunately, the two main chemicals used for flystrike control, cyromazine and dicyclanil, do not have any effect against lice and will not contribute to selection for resistance in lice.