Multiple Tools for IP Control
Dan Morrical
Iowa State University
515-294-0847
morrical@iastate.edu
Old way
Drugs, drugs, drugs
Newer, stronger, bigger
doses
No longer sustainable
No new drugs
Tools available
Knowledge
Genetics
Selective treatment
Parasite resistance
Rotational grazing
Parasite resistance
Land resource
Knowledge
High risk animals
High risk times
Dry lot versus pasture
Stock density
Knowledge
Larvae levels
Typical parasitic lifestyle
Eggs:
Development from egg to infective
(L3) larvae can occur as early as 6
days
Molt into L1’s in the egg then hatch
Nematodirus develop into L3’s in the
egg, then hatch
Most ova do not survive very cold
ambient temperatures
Typical parasitic lifestyle
L3’s - infective stage
Thick cuticle protects them from
drying
Cannot feed - finite life span
Warm temperatures increase their
metabolic rate.
Can survive some freezing
Haemonchus
Adults live in abomasum
ingest 0.05ml blood/worm/day
5000 worms will remove 250 ml of
blood.
Adults are very prolific egg layers
Haemonchus L3’s are not as cold
hardy as others
Most L3’s live for 1-3 months
Genetics
Katahdin and NSIP
Dorpers ?, Boer goats ?
Genetic resistance vs production
Selective treatment
FAMACHA
treat pale eyes
Labor
Faith
Resistance
Our parasites truly resistant
Fecal egg reduction test
Drenchrite
Refusia
Grazing management
Better forage production
Better health status
Enough nutrients to feed
sheep and parasites.
Land Resource
Pasture A
Pasture B
Hayed in 07
grazed in 07
Grazed in 08
hayed in 08
Land Resource, option b
Pasture A
Pasture B
Cattle in 07
Sheep in 07
Sheep in 08
Cattle in 08
Land Resource, option b
Pasture A
Pasture B
Pasture C
Cattle in 07
Sheep in 07
Hayed 07
Hayed in 08
Cattle in 08
Sheep 08
Sheep in 09
Hayed in 09
Cattle 09
Safe pastures
No sheep or goats from either
July 1 to December 31
or
January 1 to June 30
Alternative approaches
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Cat thyme
Sericea Lespedeza
Copper wire bolus
Fungus
DE
Research Design
Ewes:
0, .5, 1 and 2 g
Lambs:
0, .5, .75, 1.0 g
Results FEC
Ewes: Day 7
FEC increased in ewes to >2000 epg
for 0 and .5 gram dose
FEC decreased in ewes to <1000epg
for 2 g dose
Note: 2 g ewes went up to >1500epg on
day 35
Results PCV
Ewes: from day 0 to day 21
all groups went down slightly
4 ewes had to be treated with PCV
below 18
None were in the 2 gram group
Results AST
Lambs: no indication of copper
problems
Ewes: no indication of copper
problems
Base diet is pasture and TM salt
Applications
Extreme care
2 gram dose is like feeding 25 PPM
copper for 50 days
Documented resistance
Use serum AST with 2 g COWP in 5
ewes or less as first step
Summary
 Drugs
(anthelminics) are not the
solution
 Develop whole farm strategy
 Be creative
 Work with your Veterinarian
Questions