Sheep licein WA

- some current issues

Brown Besier

Dept. Agriculture and Food WA

Albany

Supporting your success

Eneabba General Store Livestock Expo March 2014

Supporting your success

• The sheep lice picture

• Chemical choice

• Chemical application

Sheep lice in WA

• How many farms in WA with lice ?

• 60 % ?

• How many sheep owners treat in any one year ?

• 80% ?

• How many treat every year, whether see lice or not?

• 71%

- Suspect light infestations ?

- Protect against re-infestation ?

Query the need to treat if sure no lice present

Why routine treatment ?

What’s NOT likely to eradicate lice ?

• Chemicals where resistance by lice is common

• Insect growth Regulators (IGRs)

• Synthetic pyrethroids (SPs)

• Long wool treatments

• Ineffective application methods

Chemical choices

Chemical choices: off shears/short wool

GROUP APPLICATION EXAMPLESAbamectin Backliner MaverickMag. Fluosilicate Dip FlockmasterOrganophosphates Backliner Eureka Gold

Dip Assassin, WhamCage dip Diazinon

Neonicinoids Backliner AvengeDip Pirhana

Spinosyns Backliner ExtinosadDip Extinosad

IGR Backliner Magnum, Zapp, Clik+Dip Fleececare, Strike

Synthetic pyrethroid Backliner CypermethrinDip Fleececare

Examples only - Dept.Agric and Food WA does not endorse any specific product.

IN WA 2013

- Offshears treatments:

Pour-on: 78%

Dip: 22%

IGR or SP: 12%

Chemical application issues

• Shower and plunge dip failures

• Getting the sheep wet:

• Dip design

• Time in dip

• Automatic jetting races

• No lice treatments registered

• Don’t wet, won’t eradicate

• Incorrect chemicals

• Diazinon by plunge or shower dip

More information

Blowfly strike management

in WA

Brown Besier

Dept. Agriculture and Food WA

Albany

Supporting your success

Reducing susceptibility to flystrike

- management and/or genetics

Susceptibility factors

Dags

Skin wrinkle

Breech cover

Long moist wool

Yellow wool, urine stain

Dermo, fleecerot

Physical injury - blood/ wounds

Most important factors determine prevention strategies

- Season

- Local environment

- Individual farm

- And appropriate prevention strategies

- Management

- Genetics

Susceptibility factors

Dags

Skin wrinkle

Breech cover

Long moist wool

Yellow wool, urine stain

Dermo, fleecerot

Physical injury - blood/ wounds

DAGS

The major breech-strike risk factor in most environments

Example: 2 weaner flocks, dags vs flystrike

Proportion of sheep in each dag score

0%

20%

40%

60%

80%

100%

1 2 3 4 5

Dag score

%

Incidence of strike with dag score- some examples in weaners (NEED MORE DESCRIPTION ABOUT THE FIGURES)

Proportion of sheep in each dag score

0%

20%

40%

60%

80%

100%

1 2 3 4

Dag score

per

cen

tag

e

n=1019

n=122n=122

0%

20%

40%

60%

80%

100%

1 2 3 4 5

dag score

% b

reec

h st

rike

n=122

Incidence of strike in each dag score

0%

20%

40%

60%

80%

100%

1 2 3 4 5

dag score

% b

reec

h st

rike

Incidence of strike in each dag score

n=170

n=1058

Dags and relative risk of flystrike

Relative risk of flystrike in weaners

x4 x7x21

Dag prevention:

- Pre-lamb ewe worm management- pasture selection- drench ?

- Worm egg counts to check burdens/ pasture contamination

- Planned annual worm control program

- Genetic:

- Cull repeat-offenders (ewes)

- Breed against scouring (hoggets)

BREECH WRINKLE

A major strike factor – high genetic hereditability

SKIN WRINKLE

Lambs from 2 different sires:

0%

10%

20%

30%

40%

50%

1 2 3 4 5

Breech wrinkle score (av 3)

Pro

po

rtio

n o

f fl

oc

k

Current flock:

average breech wrinkle score = 3

4% 28%

Example scenario: all selection on wrinkle only

0%

10%

20%

30%

40%

50%

1 2 3 4 5

Breech wrinkle score (av 2.2)

Pro

po

rtio

n o

f fl

oc

k

0%

10%

20%

30%

40%

50%

1 2 3 4 5

Breech wrinkle score (av 3)

Pro

po

rtio

n o

f fl

oc

k

Current flock:

average breech wrinkle score = 3

10 years time:

Average breech wrinkle score = 2.2

4%

21% 6%

28%

DAGS

Results after 10 years:

• Reduced wrinkle by 0.8 of a score:

• Maintained FD, body weight, reproduction

• Loss of fleece weight: - 20%

Balanced selection:

• Sires that combine desired traits

• Culling bad-trait ewes

GENETICS AND FLYSTRIKE

• Dags• Dagginess

• Worm resistance

• Breech wrinkle

• Bare breech

• Bodystrike• Conformation• Neck and body wrinkle• Fleece type/ structure• Skin disease – dermo, fleecerot• Wool - colour etc

• Individual sheep struck for “no reason”

Chemical planning assistance

Smart phone app:

“Sheep measles” – an unnecessary cause of

loss to sheep producers

Brown Besier

Dept. Agriculture and Food WA

Albany

Supporting your success

Eneabba General Store Livestock Expo March 2014

“Sheep measles”

= Cysticercus ovis

= Taenia ovis

= “ovis”

- A larval tapeworm in sheep muscle:

- visual blemish

- carcass downgrading or rejection

Tapeworm in dog intestine

Tapeworm eggs on pasture

eaten by sheep

Sheep meat or offal eaten by dog

Tapeworm develops from cysts

Eggs develop to cysts in muscle

gg

Wild dogs ?Foxes ? X

No signs of tapeworm infection in dogs or sheep

Cysts remain in sheep for life

How many properties affected ?

NSW QLD SA TAS VIC WA0

10

20

30

40

50

60

70

80

90

100

% LINES % SHEEP

gg

PREVENTION …

Faecal contamination of pasture

- Dogs roaming- Other dogs

Dog access to sheep meat- Carcasses- Rations

Worm dogs !

Worming dogs for tapeworms

• Use tapeworm-specific products: praziquantel

(Droncit, Paratak, Popantel, Tapewormer)

• In some all-wormers - but need less often

• Ideally treat 4-5 weekly

• But 3-4 times/year will go a long way

• An area treatment approach needed:

- neighbours, contractors, visitors

More information