Sustainable Control of Internal
Parasites in Sheep and Goats
Thomas Terrill
Fort Valley State University
Fort Valley, GA
Georgia Small Ruminant Research
and Extension Center
Goat research programs
• Product technology
– Meat, milk, cheese
• Nutrition and feeding
– Forages
•
•
•
•
Reproduction
Breeding (sheep and goats)
Biotechnology
Health
– Parasitology
Southern Consortium for Small Ruminant
Parasite Control (SCSRPC)
SCSRPC- International Members
SCSRPC Members - Disciplines
•
•
•
•
•
•
•
•
Parasitologists
Forage Agronomists
Plant breeders
Animal Nutritionists
Animal Scientist/Extension Specialists
Research/Extension Veterinarians
Agricultural Economists
Producers
USDA Sustainable Agriculture Research
and Education (SARE) Projects
• Sustainable Control of Gastrointestinal Nematodes in Small
Ruminants in the Southeastern USA (SARE Planning Grant)
• Novel Approaches to Sustainable Control of Gastrointestinal
Nematodes in Small Ruminants (SARE R & E)
• Smart Drenching and FAMACHA Integrated Training for
Sustainable Control of Gastrointestinal Nematodes in Small
Ruminants (SARE PDP)
• Novel methods for sustainable control of gastrointestinal
nematodes in llamas and alpacas in the southeastern United
States (SARE Graduate Student)
INTRODUCTION
 Small ruminants (goats and sheep) provide
a major source of animal protein throughout
the world
 Nematode parasites are a serious constraint
to economic small ruminant production
INTRODUCTION
 GASTROINTESTINAL NEMATODES




Trichostrongylus colubriformis
Cooperia spp
Ostertagia circumcincta
Haemonchus contortus
Haemonchus contortus
(Barber Pole Worm)
 Sheep, goats, deer, exotic ruminants
 Blood-sucking parasite
– highly pathogenic
– causes severe anemia
– causes low blood protein -- “bottle jaw”
 Most important parasite in sheep/goats raised
in warm/wet environments
– Southern USA
Life Cycle of H.
contortus
http://www.ext.vt.edu
/pubs/sheep/410027/figure1.html
Parents
Selection for
Drug Resistance
Resistant
Resistant
Drug Treatment Next Generation
CONTROL MEASURES
Anthelmintics
 Multiple anthelmintic resistance in small
ruminant GIN is a major problem in
Australia, New Zealand, South Africa,
South America, Great Britain, USA
 Cost of anthelmintics
 Concerns over drug residues in meat and
milk products
 Environmental concerns
CONTROL MEASURES
Strategic deworming
 Smart drenching
 FAMACHA
Selective Treatment
• Parasites are not equally distributed in groups
of animals
– ~20 % of animals harbor most of the worms
• responsible for most of egg output
Freq
Number of Worms
How Does FAMACHA Work ???
• Since primary impact of
H. contortus is anemia,
one can indirectly
measure parasite burden
(and need for treatment)
by measuring anemia
The FAMACHA© System
• Eye color chart with five color
categories
• Compare chart with color of
mucous membranes of sheep or
goat
• Classification into one of five
color categories:
• 1 – not anemic
• 5 -- severely anemic
Advantages of Using FAMACHA
• Reduced deworming costs
• Slow development of anthelmintic
resistance
• Identification of most susceptible animals
for culling
SCSRPC Activities - FAMACHA
• Validated use of the FAMACHA system for
sheep and goats in the USA, US Virgin
Islands (Kaplan et al., 2004; Burke et al.,
2007)
• FAMACHA workshops
– Over 550 throughout the USA, USVI, and
Puerto Rico since 2004
– Over 12,000 cards sold for on-farm use
ALTERNATIVE CONTROL
MEASURES
 Vaccines
 Resistance/Tolerance
 Nematode-trapping fungi
 Copper oxide wire particles
 Use of forages/plants
HERBAL MEDICINE
 Plant compounds with in vitro and in vivo
activity against Haemonchus contortus
–
–
–
–
–
–
Alkaloids
Triterpenoids
Benzyl isothiocyanate
Allicin
Oleanolic acid
Condensed tannins
BENEFICAL EFFECTS OF
CONDENSED TANNINS







Increased net absorption of EAAs
Increased wool growth and growth rate
Increased liveweight gain
Higher ovulation rate
Higher milk yield
Reduced bloat
Reduced detrimental effects of internal
parasites
CT-CONTAINING FORAGES
 Cool season legumes
–
–
–
–
Sulla
Birdsfoot trefoil
Big trefoil
Sainfoin
 Warm-season legumes
– Sericea lespedeza
CONDENSED TANNINS IN
FORAGES
 Vary in concentration
–
–
–
–
–
Alfalfa (none)
Birdsfoot trefoil (2-3 %)
Big trefoil (4-5 %)
Sericea lespedeza (6-7 %)
Canary clover (14%)
 Vary in reactivity
– Birdsfoot trefoil CT (low reactivity)
– Sericea lespedeza CT (high reactivity)
Sericea lespedeza




Perennial warm-season legume
High in condensed tannins
Tolerant to low pH (4.5)
Grows well on infertile soils
Sericea lespedeza
• Distribution
SERICEA LESPEDEZA STUDIES:
OBJECTIVES
 Study effects of sericea lespedeza hay on GIN
infection in goats
 Determine level of sericea lespedeza hay needed to
control parasitic nematodes in goats
 Investigate effect of pelleting on anthelmintic
properties of sericea lespedeza hay
Fecal Egg Counts
Pre-trial
3000
Trial
2500
F
2000
treatment
E 1500
C
control
1000
500
0
1
2
3
4
5
6
weeks
7
8
9
10 11
Packed Cell Volume
30
25
P
C 20
V
treatment
control
15
Pre-trial
Trial period
10
1
2
3
4
5
6
weeks
7
8
9
10 11
% larvae survived
% Larval survival in fecal cultures
80
75
70
65
60
55
50
45
40
35
30
treatment
control
Pre trial
1
2
3
Trial period
4
5
6
weeks
7
8
9
10
11
Effects on Adult Worm Species
3000
2000
Control
Treatment
of
worms
2500
Total
No
1500
1000
500
0
Haemonchus
Ostertagia
Trichostrongylus
FEC
4000
3500
3000
EPG
2500
BG 1
SL 1
SL 2
SL 3
2000
1500
1000
500
0
0
1
2
3
WEEKS
4
5
6
FEC
3500
3000
E P G
2500
Ground
Sericea
2000
Pelleted
Sericea
1500
1000
Ground
Bermuda
500
0
1
2
3
4
weeks
5
6
Conclusions
 Feeding SL hay to goats decreased FEC & improved
PCV compared to BG hay
 Feeding SL hay reduced total worm count in both
abomasum and small intestine of goats
 Optimum level of SL hay in the diet for reducing effects
of GIN in goats is 50-75%.
 Pelleting does not reduce the efficacy of sericea
lespedeza hay against parasitic nematodes
Growth rate of growing goats
70
65
weight (lbs)
60
55
Infected BG
50
Infected SL
Non-Infected BG
45
Non-Infected SL
40
35
2
4
6
8
Weeks
10
12
14
Blood Urea Nitrogen levels
40
35
BG Infected
SL Infected
Blood Urea Nitrogen
concentration (mg/dl)
30
BG Non-Infected
SL Non-Infected
25
20
15
10
1
2
3
4
5
6
7
8
9
weeks
10 11 12 13 14
Conclusions
• Sericea lespedeza hay reduced parasitic
infection levels and increased animal
performance (ADG) of growing goats
• Condensed tannins in SL increased protein
utilization efficiency in the animal
Future Research with Sericea
Lespedeza for Parasite Control
• Grazing trials with sheep and goats
– Pure stands
– In combination with other forages
– SL as deworming paddock
• Research with SL as dried feed
–
–
–
–
–
Leaf meal, pellets
Ingredient in complete feeds
Pasture supplement
Component of TMR for feedlot, confinement feeding
Beef and dairy cattle, dairy goats, llamas and alpacas,
zoo animals
Future Research with Sericea
Lespedeza for Parasite Control
• Establishment for organic small ruminant
production
• On-farm trials
– SL establishment for hay and grazing
– Use of SL grazing, hay feeding for parasite
control in combination with FAMACHA,
copper oxide wire particles
On-going Medicinal Plant Research
• Evaluation of CT-containing forage and
browse species for parasite control
• Screening for extractable and bound CT in
different forage/browse species
• Screening for in vitro anthelmintic activity
(larval motility, egg hatch assays)
• Screening for in vivo anthelmintic activity
(gerbils, goats, sheep)
COWP
• Copper oxide wire particles (COWP) have been
used to treat copper deficiency
• COWP become lodged in the abomasum resulting
in expulsion or death of the adult nematode
• COWP have been used in sheep and goats to
reduce GIN in the animal
Copper oxide wire particles
(COWP)
• Commercially available as a 25g bolus to
treat copper deficiency in cattle (Copasure,
Animax Ltd, Stanton, UK)
Effect of COWP on FEC of lambs
Fecal egg count, egg/g
12000
*
*
10000
*
8000
*
0g
2g
4g
6g
6000
4000
2000
+
+
0
0
7
14 21 28 35 42 49 56
Days after inoculation with H. contortus
FECAL EGG COUNTS (EPG)
8000
TRIAL PERIOD
POST-TRIAL PERIOD
7000
6000
E P G
5000
4000
lamb cowp
3000
lamb nocowp
2000
kid cowp
kid nocowp
1000
0
1
2
3
WEEKS
4
5
6
PACKED CELL VOLUME
30
TRIAL PERIOD
POST-TRIAL PERIOD
28
26
24
E P G
22
20
lamb cowp
lamb nocowp
18
kid cowp
16
kid nocowp
14
12
10
2
3
WEEKS
4
5
6
ADULT WORMS - GOATS
COWP
NO COWP
7000
NUMBER OF ADULT WORMS
6000
5000
4000
3000
2000
1000
0
TOT HAEMONCHUS
TOT OSTERTAGIA
TOT ABOMASUM
Conclusions
• COWP effective against parasitic worms in
both lambs and kids
• COWP more effective against abomasal
than small intestinal worms
• More effective in young stock than older
animals
• No signs of Cu toxicity, but greater concern
with sheep
Future Research and Outreach
Activities of the SCSRPC
• Continued development and evaluation of alternative
(non-chemical) parasite control technologies
• Integrate selective treatment (FAMACHA) with novel
control methods (COWP, CT forages) for on-farm
testing with small ruminants
• Application of these principles to other livestock
species (cattle, horses, llamas & alpacas, zoo animals)
• Development of organic small ruminant production
systems
Future Research and Outreach
Activities of the SCSRPC
• Continue FAMACHA and Smart Drenching producer
workshops
• ‘Train the trainer’ workshops on sustainable parasite
control
• Continue expansion of SCSRPC web site to include
more producer-friendly publications
• Impact assessment of FAMACHA, novel parasite
control techniques
• Economic analysis of sustainable parasite control
systems for small ruminants
RESOURCES
• Information on small ruminant parasite
control
– SCSRPC.org
– WormX.org
• Seed source for ‘AUGrazer’ sericea
lespedeza
– Sims Brothers Seed Company, Union Springs,
AL (334-738-2619; simsbrothers.com)
Acknowledgements
• USDA-SARE
• Southern Consortium for Small
Ruminant Parasite Control
• Fort Valley State University
Any Questions ?