Discussion on natural parasite control strategies

1. Natural Parasite Control in Sheep and
Goats
Dahlia O’Brien
Extension Specialist – Small Ruminants
Virginia State University
March 10, 2016
dobrien@vsu.edu
(804) 524-6963

2. Today’s Topics
• Anthelmintic resistance
(AR) and it’s status in the
U.S.
• Natural parasite control
strategies
o Pasture and grazing management
o Genetic Selection
o Nutrition
o Herbal dewormers (garlic, ginger,
pumpkin seeds etc.)
o Copper Oxide Wire Particle (COWP)
o Condensed tannins (Sericea
lespedeza)
o Others
• Take away points

3. Anthelmintic Resistance (AR)
• Ability of worms in a
population to survive drug
treatment of the animal at the
standard prescribed dosage
• Internal parasites (worms)
have developed resistance to
all dewormers and all classes
of dewormers
• No chemical treatment kills
100% of worms
• Two new classes of dewormers
available in some countries
(not U.S.) with resistance
already reported

4. AR Status in U.S.
0
10
20
30
40
50
60
70
80
90
100
Mid-Atlantic (33)
South (46)
100%
98%
82%
76%
47%
24% 24%
54%
Haemonchus contortus prevalent internal parasite on these farms
Mid-Atlantic (2008 – 2009) and South (2008)

5. Pasture Management
• Should be the primary tool that
producers use
• Very few worm larvae get
higher than 2 inches from the
ground on a plant
• Preventing animals from
grazing below this reduces the
number of worm larvae
ingested
• Larvae migrate approximately
12 inches from a manure pile
o Provide areas where animals
can browse and eat away from
manure/higher off of the
ground
• Reduce the stocking rate
o Reducing the # of animals
o Reducing the amount of time
animals graze

6. Pasture Management
• Internal parasites of sheep and
goats are different from the
parasites that affect other species
such as cattle and horses
o Cattle/horses “vacuum” sheep/goat
pastures helping to clean the
pasture for sheep and goats
o Lead with more susceptible
species/classes
• Provide access to browse and
bioactive forages (such as sericea
lespedeza)
• Provide diverse forages
• Provide clean pastures for young
and other susceptible stock

7. Pasture Management
 Pasture rotation and rest is an
important factor in limiting parasite
infections
 Moving sheep/goats every 4 – 5 days
has been shown to be effective in
avoiding worm infections
 When is it safe to return animals to a
pasture?
 Depends on worm species, temperature,
moisture, forage type and individual
animal immune status
 When the barber pole predominates,
resting pastures for 60 days has shown
good results
 Due to increased stocking rates,
management of intensive grazing may
increase internal parasite problems in
sheep

8. Genetic Selection
 Animal selection is one of the
best long-term strategies for
managing internal parasites
 There are several breeds of
small ruminants that
demonstrate resistance to
parasites
 Resistance – ability of
host/animal to limit infection
(assessed by fecal egg counts)
 Sheep breeds include:
 Gulf Coast Native
 St. Croix
 Barbados Blackbelly
 Goat breeds include:
 Spanish
 Kiko
 Myotonic

9. Genetic Selection
• Resistance varies among
individuals within breeds as well
• The 70/30 or 80/20 rule
o 20 - 30 percent of flock shed 70 –
80 percent of the parasite eggs in a
flock/herd
o Focusing deworming on
susceptible animals will
significantly reduce pasture
contamination
o More parasite resistant animals
decrease the need for deworming
o Culling parasite susceptible
animals will increase flock
resistance, reduce pasture
contamination and decrease
deworming frequency

10. Genetic Selection
 In addition to resistance, there
are some animals that are more
tolerant of parasite loads than
others
 These animals are considered to
be resilient
 Resilience - ability of
host/animal to withstand
challenge and/or /infection
(assessed by FAMACHA© and
hematocrits
 These resilient animals tend to
always be wormy (high FEC)
yet demonstrate few if any
signs of parasitism (good
FAMACHA scores etc.)

11. Nutritional Management
 Good nutrition supports the
immune system and makes
animals more tolerant of internal
parasites and possibly be more
resistant
 Protein – aids in rebuilding
tissue damaged by worms
 Minerals such as copper and
zinc support a good
immune system
 Research has showed that ewes
receiving higher levels of protein
for 6 weeks prior to lambing
have significantly lower fecal
egg counts

12. Nutritional Management
• Supplementing lambs has
also been shown to
increase gains and
hematocrits
• Legumes also provide
more protein so access can
help to protect your
animals from internal
parasites
• “Zero-grazing” – small
ruminants raised on a dry
lot will have less parasite
issues

13. Herbal Dewormers
• Molly’s Herbals Worm
Formula
(www.fiascofarm.com)
• Hoeggar’s Herbal
Wormer
(www.hoeggerfarmyard.c
om)
• Garlic
• Papaya
• Pumpkin
• Ginger
• Others such as
wormwood and fennel
Information available is anecdotal mostly and limited research
has been conducted to provide further verification

14. • On-farm
o Use of 1 tsp. (5 ml) garlic juice has been effective against worms in lambs
(http://www.garlicbarrier.com/2003_SARE_Report.html)
Herbal Dewormers - Garlic

15. • Three controlled studies
(Burke and colleagues,
2009) – all animals treated
once
o Experiment 1: 1.7 oz. of garlic
juice (diluted Garlic Barrier; 1:1)
o Experiment 2: 1.4 oz. of freshly
squeezed garlic juice/2 – 3 bulbs of
garlic
o Experiment 3: papaya (80 g/2.8 oz.
diluted to 110 ml with water)
Herbal Dewormers – Garlic
and Papaya

16. • Meat goat kids treated with 0.1 oz. /lb. body weight
(Gooden, 2012) – treated every other day
Herbal Dewormers – Papaya

17. • Meat goat kids fed pumpkin seeds top-dressed on feed (PUM;
0.08 oz./lb.) or not (CON) every day for 21 days (Matthews et al.,
2016)
• Two animals removed from PUM group due to high FEC and
clinical symptoms
Herbal Dewormers – Pumpkin
Project funded by Northeast Sustainable Agriculture Research
and Education grant: Project #LNE08-269
0
1000
2000
3000
4000
5000
6000
7000
8000
0 7 14 21
Fecaleggspergram
Time (days)

18. • Meat goat kids treated with a pumpkin seed drench (PUM; 0.08
oz./lb.), ginger drench (GIR; 0.05 oz./lb.) or no treatment (CON) every
other day over a 42-day period
• At slaughter, CON group had more worms (1,857) compared to both
the GIN (549) and PUM seed (869) drenched groups
Herbal Dewormers – Pumpkin and
Ginger
NO animals in the PUM group displayed clinical
symptoms/required deworming
-2000
0
2000
4000
6000
8000
10000
0 7 14 21 28 35 42
Fecaleggspergram
Time (days)

19. Commercial Herbal Dewormer
• Using commercially available
herbal wormers can be a
promising and viable
alternative to chemical
control
• Natural
• No environmental
hazards
• No need for withdrawal
periods
Hoegger’s Herbal Wormer (Hoegger’s Goat Supply, Fayetteville,
GA: containing wormwood, gentian, fennel, psyllium and quassia)
Molly’s Herbal Worm Formula Kit (Fias Co Farms: containing
wormwood, black walnut and other natural products)

20. • Hoegger’s Herbal
Wormer (HHW) - meat
goat kids drenched with
manufacturer's
recommended dose or
not (CON) over a 35 day
period
• Natural infection (>50%
H. contortus)
• HHW did not reduce FEC
in kids
Commercial Herbal Dewormer
0
500
1000
1500
2000
2500
3000
3500
0 7 14 21 28 35
CON
HHW

21. • Hoegger’s Herbal Wormer
(HHW) - lactating meat
does drenched with
manufacturer's
recommended dose or not
(CON) over a 70 day period
• Natural infection (>62% H.
contortus)
• FEC increased by 535% in
the CON group and only by
182% in the HHW group by
the end of the study
Commercial Herbal Dewormer
0
500
1000
1500
2000
2500
3000
3500
4000
0 14 28 42 56 70
FEC(epg)
Time (days)
CON
HHW
*1
*1
*2
*1
*3
Eight total dewormings (6/8 CON and 2/8 HHW)

22. • Molly’s Herbal Worm
Formula Kit (Burke and
colleagues, 2009)
o Formula 1 – wormwood, garlic,
fennel, black walnut, and sweet
weed
o Formula 2 – field pumpkin,
mugwort, garlic, fennel, hyssop,
thyme and sweet weed
o Dose administered according to
manufacturers recommendations
Commercial Herbal Dewormer
FAMACHA© scores were higher for the herbal treated goats
No reduction in worm counts observed

23. • There is anecdotal evidence that herbal dewormers work
• Lack of scientific support
• Inconsistent data when support is available
Herbal Dewormers
**Active ingredients vary**
**Common names do not always refer to the same plant**
**Dose recommended not high enough to produce anthelmintic properties**
Cautious – some herbs are toxic!
Herbal products/dewormers should always be combined with other integrated
parasite management techniques
Know the status of drug resistance on your farm so that these techniques can also be
used in conjunction with an effective chemical dewormer

24. • COWP are available commercially
to alleviate copper deficiency in
ruminant livestock
o Copper is important for immune
function
• Sheep sensitive to copper –
margin of safety between the
required amount of coper (10
ppm) and the toxic level (25 ppm)
is very narrow
o Some sheep breeds are more
sensitive than others
o Goats are less susceptible and can
tolerate up to 80 ppm
o The form of copper used in
COWP is poorly absorbed,
reducing the risk of copper
toxicity
Copper Oxide Wire Particles
(COWP)

25. • Multiple studies have been conducted showing that COWP (Copasure®)
treatment is effective against Haemonchus contortus (barber pole worm)
o Mode of action – indirectly by acting on adult worms in animals abomasum (true
stomach) due to increased copper or directly by penetrating the cuticle of the
worm
• COWP can be included in an integrated gastrointestinal nematode (GIN)
control program, specifically to control Haemonchus contortus
Copper Oxide Wire Particles
(COWP)

26. • Use the smallest dose of
COWP needed to achieve the
desired effect
• Young – uses 0.5 to 1 gram per
head
• Older/mature animals - 2 to 4
grams per head
• Use lower doses in sheep and
in smaller goat breeds
• Depending on dose do not
give more than 2 – 4
treatments in any one grazing
season
• At least 6 weeks should elapse
between treatments
Copper Oxide Wire Particles
(COWP)

27. Condensed Tannins
• Tannins are plant compounds
that bind to proteins and other
molecules
• Sericea lespedeza (AU grazer™)
is a high-tannin forage (4–15%
DM) that has been scientifically
proven to reduce parasite loads
in sheep and goats
• The mechanism of action is not
yet known.
o By tannins reacting directly with
adult worms by attaching to their
“skin”, causing them distress
o Indirectly by improving protein
nutrition of the goat and boosting
the immune system

28. • Fresh (grazed), dried (hay, leaf meal, pellets), or
preserved (ensiled) forms of SL tested so far have showed
some level of anti-parasitic activity against worms,
particularly H. contortus
• Also effective against the protozoan parasites (Eimeria
spp.) that cause coccidiosis
Condensed Tannins

29. • Forage chicory – the FEC of lambs grazing chicory
increased less than those grazing sudangrass in Ohio
(McCutcheon et al., 2012)
• Lambs grazing chicory had consistently less FEC and
grew faster than lambs grazing grass/clover
Condensed Tannins

30. Others – Diatomaceous Earth
• Diatomaceous earth (Diatomite)
is the skeletal remains of single-
cell algae, and there are claims
that it can serve as an effective
alternative dewormer for
animals
• Diatomaceous earth has been
used for many years for control
of various pests
• As a deworming control it is
often mixed with the mineral
supplement or in the feed
• Anecdotal claims
o Extends the time between dewormings
o Kills worms in goats
• Scientific data
o diatomaceous earth does not kill worms in
goats
o One study did show that at a very high level
(5% of the diet), it had a slight effect
It is used as a food ingredient and
in swimming pool filters

31. Others – Diatomaceous Earth
• Anecdotal claims
o Extends the time between
dewormings
o Kills worms in goats – 2% DE in
feed kills internal parasites
including tapeworms and
roundworms
• Scientific data
o Shown to have insecticidal
properties
o The majority of controlled
studies in sheep, goats and cattle
show no significant impact on
internal parasite infection

32. • Nematode trapping fungi
(Duddingtonia flagrans), have
been studied with varying
results
• D. flagrans is a nematode
trapping fungus that survives
passage through the digestive
tract of livestock, germinate
and spread on fresh feces
producing specialized
nematode trapping structures
that restrict the development
of parasite larvae
• Not available in the U.S. at this
time
Others – Nematode trapping fungi
Successfully applied under field
conditions with cattle, sheep and
goats

33. • Australia has developed a strain of D. flagrans that provides control
at a dose of 30,000 spores/kg body weight
o Previously doses of up to 1,000,000 spores/kg body weight has been
used in kids and lambs
• Expected that this will be available as a feed additive in Australia
the near future
Others – Nematode trapping fungi

34. • Haemonchus (barber pole
worm) vaccine is
commercially available in
other countries for sheep
(lambs only)
• Might “never” be available
in the US
o It is very costly to make
o Supply is limited (into the near
future) even though demand is
high
o Not enough sheep in the US
• Other types of vaccines are
being investigated
o Not sure if any are being
developed for the market
Others – Vaccine

35. Take away points
 They should always be combined with other
integrated parasite management techniques
 Sericea lespedeza and copper oxide wire
particles are two effective natural
deworming products that can be
incorporated into an integrated/sustainable
control program for worm control in sheep
and goats
 There is strong evidence that anthelmintic
resistance has reached critical levels
throughout the entire Eastern United States
 Sustainable integrated parasite management
(SIPM) practices must become the new
standard
 Most scientific studies have found that
natural products fail to reduce worm counts
in sheep and goats
 Herbal products alone should not be relied
on for controlling/treating internal parasites
It is important to know the status of drug resistance on your farm so that these techniques can also be used in conjunction
with a more targeted and strategic manner of deworming following the principles of ‘Smart Drenching”

36. Thanks for you
attention