Control of ecto and endo parasites

Question 1

Non chemical measures for GIN

Answer 1

1. grazing management
2. using immunity to worms
3. genetic selection for resistance
4. vaccination (not yet)
5. integrated strategic drenching programs

Question 2

Factors: Age

Answer 2

young animals get more worms, suffer more serious disease and shit out more eggs onto pasture

Question 3

Grazing history

Answer 3

Animals exposed to heavily infected pastures get more worms

Question 4

Climate

Answer 4

The weather affects which worm species are found in a locality. Warm, wet weather advantages parasites to develop and survive on pasture

Question 5

breed

Answer 5

Some breeds and lines of sheep inherently carry fewer worms

Question 6

Nutrition

Answer 6

Improved nutrition can reduce worm numbers and production costs of worms by boosting resistance

Question 7

Immunity/resistance

Answer 7

Sheep develop immunity as they age. Older (immune) sheep carry fewer and suffer less from disease

Question 8

Principles of worm control

Answer 8

1. Worm life cycle and pasture numbers; warm and moist conditions enhance build-up and survival
2. survival of L3 on pasure- extremes are usually lethal. Warm to hatch, cool to dry
3. L3 don’t feed. Sooner or later run out of energy- faster w warmth
4. rainfall zones

Question 9

IPM strategies PxE

Answer 9

1. Reducing development of parasite eggs on pasture
2. Minimising infective stages (L3) available for infection
3. Minimising infective (L3) ingested

Question 10

IPM strategies HxP

Answer 10

1. Minimising worms establishing and completing life cycle w egg production
2. minimising eggs coming out of hosts
3. maintaining host production (minimising prod. losses)
4. Checking to ensure it is working

Question 11

Grazing management: Strategies for reducing pasture contamination

Answer 11

1. Spelling for 3-6 months esp over summer
2. Cropping, forage, bushfires
3. Grazing w adults or a different species (not goats)
4. Keep pasture long, strip grazing
5. Drench, hold and move to low L3 pasture

Question 12

Innate immunity

Answer 12

30% of worms don’t establish in naiive lambs due to steroid sensitivity

Question 13

Inflammation

Answer 13

worms don’t like a hostile location- inflammatory mediators expel worms

Question 14

Acquired immunity

Answer 14

• allergic TH2- type responses are involved in protection
• induction of immunity is worm-specific, effector phase is non-specific (inflammatory mediators), expelling unrelated worms in same location

Question 15

Breeding for resistance

Answer 15

• animals can be selected for resistance

- reduced epg is correlated w increased bodyweight

Question 16

DrenchPlan is an integrated worm management combining

Answer 16

1. the effective use of drenches
2. grazing management
3. flock management including early weaning
4. breeding sheep more resistant to worms
5. nutrition
6. fine-tuning based on regular worm egg count monitoring (WormTest) and drenching efficiency testing (DrenchTest)

Question 17

IPMS aims to

Answer 17

reduce infection of susceptible stock by minimising pasture L3

Question 18

IPMs reduce selection pressure for resistance by

Answer 18

reducing the frequencing of drenching

Question 19

IMPS require

Answer 19

effective drenches

Question 20

Managing anthelmintic (anti-parasite drugs) resistance required an entirely different strategy:

Answer 20

Aims to dilute out Res worms w Sus ones, so contaminates pasture

Question 21

Prevention: break lifecycle

Answer 21

1. Stop dog (final host) eating infected animal tissue
2. Prevent transmission to livestock by stopping dog shit spread
3. Treat infected dog with anthelmintic
4. Employ measures to prevent wild dogs from roaming on grazing pasture or contaminating it with eggs (bait on property with praziquantel)

Question 22

Ectoparasite IPM scheme

Answer 22

1. Environmental control
2. Attention to susceptible groups (young,stressed) esp for nutrition
3. Rational use of effective chemicals
4. breeding for resistance
5. nutrition, vaccination
6. Monitoring and feedback; production and chemical efficacy

Question 23

Benzolyphenylureas and triazines

Answer 23

chitin synthase inhibitors used for flies and lice

Question 24

Juvenile Hormone

Answer 24

used for fleas and roaches

Question 25

Environmental control for parasites with life cycles entirely on animal:

Answer 25

• removal of hair/fleece to enable access of chemicals
• chemical treatment, dip, backliner
• preventing animal to animal transfer- cages
• clean up shed hair, bedding