Dewormer efficacy against Cooperia
The repetition of using the same class of dewormer year after year, has led to
the selection of parasites resistant to that class of dewormer. This can result
in ineffective treatment and economic losses 4.
Furthermore, at the termination of this study, the Cooperia-infected calves were
split into two groups to evaluate efficacy of deworming protocols. The calves were
dewormed with two different classes of anthelmintics. One pen was dewormed
with a Macrocylic lactone, Doramectin
FECRT efficacy is evaluated
(Dectomax®) at 200 mcg/kg and one
pen with a benzimidazole, Fenbendazole
as a percent reduction in
(Safe-Guard®) at 5 mg/kg. A Fecal
the average number of eggs
Egg Count Reduction Test (FECRT)
per gram from the first Fecal
was performed with Fecal Egg Counts
collected on the day of deworming
Egg collection to the second
(day 60) and 14 days later (day 74).
collection 14 days later.
(A 90% or greater reduction
is required to qualify as a
successful deworming)
Treatment of infected calves with the
endectocide did not remove the Cooperia
parasites as demonstrated by FECRT
results that showed an 8.8 percent
reduction in average egg counts 14 days
after treatment. Meanwhile, treatment with a benzimidazole was shown to be very
effective against Cooperia as the group of infected calves treated with Safe-Guard
showed a 98.1 percent reduction in egg counts 14 days after treatment.
To verify FECRT results, necropsies were performed on three animals from
each treatment group. Researchers found an average of 24,600 Cooperia worms
in the small intestine of the endectocide-treated animals, and only 167 in the
small intestine of the benzimidazole-treated calves1.
Necropsy worm counts 14 days Post treatment with either
Fenbendazole (Safe-Guard®) or Doramectin inj. (Dectomax®)
Treatment Study
FBZ
Abomasum
Sm Int
Lg Int
Caecum
9
0
100 Cooperia
ns
ns
38
0
400 Cooperia
ns
ns
53
0
0
ns
ns
DOR
Abomasum
Sm Int
Lg Int
Caecum
120
100 Cooperia
31,500 Cooperia
ns
ns
132
100 Cooperia
6,600 Cooperia
ns
202
200 Cooperia
35,700 Cooperia
ns
ns
1
Stromberg, B.E., et al., Cooperia punctata: Effect on cattle productivity? Vet. Parasitol. (2011), doi: 10.1016/j.vetpar.2011.07.030
2
L.C. Gasbarre et.al., Veterinary Parasitology 166, 2009, 275-280
3
J.F. Urban Jr. et al, Veterinary Parasitology 148, 2007, 14-20
4
Gasbarre LC, Smith LL, Pillit PA (2005), Identification of cattle nematode parasites resistant to multiple classes of anthelmintics
in a commercial cattle population in the US., Amer Assoc Vet Parasitol Proc; July, 57
556 Morris Avenue • Summit, NJ 07901 • merck-animal-health-usa.com • 800-521-5767
Copyright © 2011 Intervet Inc., a subsidiary of Merck & Co., Inc. All rights reserved. 9/11 BV-SG-43605
ns
Results of UDSA NAHMS Beef
2007-2008 Cow-Calf Survey
TECHNICAL BULLETIN
Prevalence
Cooperia sp.
91.2%
Ostertagia
79.1%
Haemonchus
52.9%
Hamatodirus
18.0%
Resistance to Macrocyclic
Lactones 2009
WA
MT
OR
ID
NV
CO
OK
OH
IN
MO
WV
VA
KY
NC
TN
SC
AR
MS
TX
NY
MI
PA
IL
KS
NM
WI
IA
NE
UT
AZ
MN
SD
WY
CA
VT
ND
AL
GA
LA
FL
Confirmed
NH ME
MA
RI
CT
NJ
DE
MD
THE EFFECTS
OF COOPERIA PUNCTATA
ON CATTLE PRODUCTIVITY
Suspect
New parasite enemy number 1 has negative impact
on production and profits
A new study shows that
Cooperia punctata – often left
behind by popular avermectin
dewormers (macrocyclic
lactones) – reduces intake
and rate of gain. In a recently
peer-reviewed research study
by leading cattle parasitologists,
Cooperia-infected calves gained
7.4% less weight and consumed
1.5 pounds less per head per day
on a dry matter basis1.
Overview
“For decades, the brown stomach worm, Ostertagia, was believed to be the
most pathogenic and economically costly of internal cattle parasites,” says Bert
Stromberg, Ph.D., professor of parasitology at the University of Minnesota. “And
to their credit, avermectin dewormers like pour-ons did a good job of controlling
the brown stomach worm.”
Cooperia punctata has become the most prevalent internal parasite in U.S.
cow-calf operations according to research data from USDA’s National Animal
Health Monitoring Service (NAHMS) Beef 2007-2008 cow-calf survey. The effects
of Cooperia punctata on cattle productivity, however, have not been studied and
have largely gone unchecked.
In a closely controlled study carried out in the fall of 2009, leading cattle
parasitologists sought to find out just how big of an impact Cooperia punctata,
the new enemy number 1 of cattle parasites, really has on cattle production.
Study design
Data collection
In the Fall of 2009, two hundred calves with an average weight of 460 pounds were
acquired from Northwestern Arkansas and Northeastern Oklahoma salebarns and,
upon arrival, were vaccinated for IBR, BVD Type I and Type II, PI3, BRSV, (Vista 5® ) and
given a 9-way clostridial vaccination (Calvary 9 ®), implanted (Ralgro®) and administered
metaphylactic therapy (Excede®). The calves were also drenched with fenbendazole at
5 mg/kg (Safe-Guard®) and given levamisole (Levasole® boluses) at 8 mg/kg. Males were
surgically castrated and all animals were preconditioned for approximately one month
and fed a standard growing ration made up of steam flaked corn, chipped alfalfa hay,
cottonseed hulls, corn gluten, trace minerals, molasses, fat and micro-ingredients.
Data collected included biweekly fecal egg counts, daily individual feed
consumption and weight gain over the 60-day test period. Egg counts were
positive by day 14 post-infection and remained at levels similar to those
seen in previous field studies2.
Results
Effects on Production (deads in basis)
At four weeks, all calves were dewormed through their feed using fenbendazole
(Safe-Guard® 1.96% mini pellet), re-vaccinated with IBR, BVD Type I and Type II,
PI3, BRSV, (Vista 5®), and at this time the best (healthiest) 160 calves were moved to
pens equipped with GrowSafe® system feed bunks. After an additional week to get
acclimated, calves were randomly divided into two groups of 80 – a control and infected
group. Each group of 80 was further divided into two replicate pens of 40 calves each.
The study was comprised of two treatments and two replicates (pens) containing 40
animals each, for a total of 160 animals on the study.
Infected
21
28
35
42
49
56
0.0
0.0
0.5
0.5
1.0
1.0
0.2
1.0
4.2
0.0
1.2
0.8
2.5
1.9
0.4
n
all
19
20
20
20
20
20
75
Mean
0.00
65.2
167.0
81.7
142.6
87.0
79.2
55.8
55.8
204.8
85.2
188.9
165.0
198.3
163.0
18
50
50
50
18
20
74
n
•
•
•
all
Egg count data (SD greater than the Mean) showed the overdispersed distribution characteristic of GI nematode infections under natural conditions – indicates previous exposure to infection
EPG values similar in magnitude to values seen in field studies2
Drench containing Cooperia was 99%+ pure Cooperia but did contain a small amount of other genus internal parasites (Haemonchus, Oestertagia)
Worms 35 days Post-infection
Ave
Consumption
(DMI)
Uninfected
1
616.2
801.4
3.22
27.9
3
626
818.9
3.25
27.5
Avg
621.1
810.2
3.24
27.7
2
621.3
792.5
2.92
26.3
4
619.7
802
3.07
26.3
Avg
620.5
797.3
3.0
26.3
0.6
12.9
0.24
1.5
7.4
5.4
The results are significant when
you consider that a typical 100-head
pen of calves infected with Cooperia
could consume 4.5 tons less feed
and leave behind 1,440 pounds of
unrealized gain over an equivalent
60 day period.
Necropsies of infected calves performed on days 35 and 60 after infection
with Cooperia larvae revealed considerably enlarged mesenteric lymph nodes.
This finding may indicate a powerful Th 2 type immune response to parasite
infection3.
14
Standard Deviation
ADG
Effects on health
0
Standard Deviation
Ave.Weight
Day 61
The calves free of Cooperia gained weight 7.4 percent more rapidly than
infected calves – gaining 3.24 pounds per day versus 3.0 pounds per day.
These animals also consumed 1.5 pounds more feed per head per day on
a dry-matter basis compared to the Cooperia-infected animals.
Fecal Egg Count Levels (arithmatic means)
Uninfected
Ave. Weight
Day 0
Difference
% Difference
Data collection
Mean
Pen
Infected
GrowSafe® system feed bunks measure feed
intake in grams for each individual animal
On day 0 and day 14 of the data collection phase, two pens were orally drenched with
Cooperia punctata infective larvae obtained from a field study in Wisconsin (approx
100,000 larva on day 0, and approx 95,000 on day 14). The two control (non-infected)
pens received a drench of tap water. To mimic natural infection, researchers sought to
infect animals so that, on average, animals carried between 10,000 and 20,000 worms.
The presence of Cooperia punctata (>99%) was later confirmed by necropsy on days
35 and 60 post infection.
Day
Treatment
“The immune system can become hyper-stimulated and go into over-drive.
The result is the suppression of Th 1 immune responses that are needed to
fight off viruses and develop protective immunity from your vaccination
programs,” explains Lou Gasbarre, now retired Research Leader from USDA’s
ARS Bovine Functional Genomics Lab in Beltsville, Md.
Necropsies also revealed thickening of the intestinal wall and significant
mucus production.
Swollen Mesenteric lymph nodes may
indicate a powerful Th 2 immune response
to parasite infection2.
Worms 60 days Post-infection
Infected
Abomasum
Sm Int
Lg In
Caecum
Infected
Abomasum
Sm Int
Lg In
Caecum
19
900
Heamonchus
15,600
Cooperia
0
0
12
0
15,600
Cooperia
0
0
31
700
Ostertagia
27,100
Cooperia
100
Cooperia
0
109
100
Cooperia
27,100
Cooperia
100
Cooperia
0
113
200
Heamonchus
26,400
Cooperia
0
0
Control
Abomasum
Sm Int
Lg Int
Caecum
44
0
0
0
0
96
0
0
0
0
186
0
0
100
Cooperia
0
100
Haemonchus
162
100
Cooperia
15,900
Cooperia
0
100
Oesophagostomum
Control
Abomasum
Sm Int
Lg Int
Caecum
45
0
0
0
0
105
0
0
0
0
143
0
0
0
0
Infections appear to induce a marked change
in the intestinal wall of the small intestine.