1. Don’t let internal parasites affect performance!
CATTLE U
Marc Campbell DVM
Bayer AH VSL
July 31, 2019
/// Bayer 16:9 Template 2010 /// November 2017

2. Parasites of Cattle Arthropods (Flies, Ticks, etc) Protozoa (Coccidia)
Cestodes (Tapeworms)
Trematodes (Flukes)
And………….Nematodes (WORMS!!)

3. Estimated Losses in U.S. Cattle due to Parasites
Horn Flies $1.36 billion
Stable Flies $672 million
Horse Flies $296 million
Face Flies $191 million
Ticks $162 million
Mosquitoes $78 million
Lice $59 million
NEMATODES (Worms)
$2 BILLION
Based on Kunz et al 1991 and adjusted for inflation rates

4. Ideal environment for larval development
40-90 degrees F (50-90 most)
Optimum temperature is degrees F
High humidity is best
Best transmission times are Spring and Fall

5. Nematode Life Cycle (Circle of Life)

6. Nematode Life Cycle

7. Fecundity of Adult Nematodes
Ostertagia- 300 eggs per day
Haemonchus- 5,000-10,000 eggs per day
Cooperia- 1,000-3,000 eggs per day
Nematodirus eggs per day

8. Gastrointestinal Nematodes
Eggs
Hatch in 2-3 days
Cold temperatures delay development
Desiccation most detrimental

9. Gastrointestinal Nematodes
Larvae
L1, L2 - feed in manure pat

10. L3 Nematode Quest (horizontal and vertical)
-5 cm vertical and about 20cm horizontal
80% of parasites can be found below 5cm
Rainfall and dung dwelling creatures can increase radius greatly
Cattle usually won’t graze within 18 inches of fecal pats

11. L3 Nematode Can also undergo a phenomenon known as “Anhydrobiosis”
This is a dormant state induced by drought or cold in which an organism becomes almost completely dehydrated and reduces its metabolic activity
This can happen up to 7 times (this is why parasite burdens can be worse after an extended drought!)

12. Parasite Management Effort and Focus
Parasite treatment
(fall deworming)
Targets 10% of the
parasite population
Parasite management & prevention
(strategic or spring deworming)
Targets 90% of the
parasite population
“There are two general approaches to minimize losses caused by cattle worms:
First, we can treat worm problems during fall; this approach only eliminates the worms that are in the calves and cows as they are coming off the pasture. It does not prevent the losses that occur while they’re on the pasture, and it only eliminates approximately 10% of the worm population owned by the producer (only 10% of the population are in the animals at any time; the rest are living in the pasture). It can, however, reduce the cost of “housing” these nematodes over the winter in these animals.
Or, the other approach is to develop a strategic deworming program that targets both the 10% of the worms in the animals and the 90% present as eggs or juveniles in the pastures. This strategic program can prevent the losses that occur on the pastures and the losses that occur during the winter.”
Hildreth AVC presentation 12/08

13. Internal Parasite Predilection Sites

14. Relative Importance of Cattle Worms
How Common
Relative Pathogenicity
Cooperia
Ostertagia
Oesophagostomum
Strongyloides
Haemonchus
Trichostrongylus
Nematodirus
Dictyocaulus
Trichuris
Bunostomum 14 14

15. Ostertagia Causes Anorexia

16. Sub Clinical Parasitism
Diarrhea
Bottle jaw
Anemia
Rough hair coat
Sub Clinical Parasitism
Reduced milk production
Reduced Reproductive performance
Reduced Milk Quality
Increased susceptibility to disease
Reduced growth rate
Reduced weaning weight

17. Deworming is the most valuable tool to cow/calf producers
Parasite losses are usually subclinical (not seen externally)

18. Figure 1. Relative weights of clean sections of the sheep GI Tract by state of parasite challenge (Jacobson et al, Vet. Parasit. 161: )

19. 5 Cardinal Signs of Inflammation
Heat
Redness
Swelling
Pain
LOSS OF Function!!

20. The Impact on Immunity Parasites compromise the immune system.
Parasites “create” an immune response.
Resulting in profound immune system changes.4
Parasites turn off some immunological function.
That means a parasitized animal can’t mount an appropriate response to a health challenge, and vaccinating that animal may be less effective.”4
4Gasbarre L. Effects of gastrointestinal nematodes on the bovine immune system. Veterinary Parasitology. 1997:72(3-4):

21. Controlling Worms While Grazing “Helps” with Diseases While Feeding
Smith, R.A. et al, 2000.
FBZ during pasture on days 0, 28 and 56.
FBZ at feedlot on day 118

22. Can Parasites Effect Milk Production?

23. Milk Production. Results Increase in milk production of 2.07 lbs./day
In a recent study, even eliminating low (sub-clinical) parasite burdens in lactating cows produced a consistent increase in milk production.* This study included 28 herds and 954 cows in Canada.
Results
Increase in milk production of lbs./day
Immediate drop in egg counts that lasted at least 100 days
Return on investment on more than 7:1
*Data on file

24. Reproductive Benefits of Deworming?

25. Average of a 12% Increase in Conception Rate
Reproduction
97% vs 85% the first year
91% vs 78% the second year
Average of a 12% Increase in Conception Rate

27. Manage Cows for Reproduction
Length of Calving Season
140 Days
60 Days
Calves Born in
Number
Weight
1st 20 days 25
540 50
2nd 20 days 22
510 30
3rd 20 days 18
480 20
4th 20 days 12
450
----
5th 20 days 10
420
6th 20 days 8
390
7th 20 days 5
360
Overall
100
478 lbs.
519 lbs.
This slide shows the impact of having cows breeding late and ultimately calving late. Most operations have a few cows with late calves. In this example, 65% of the calves are born in the first 60 days. It’s not unheard of for 65% of the calves to be born in the first 20 days in herds that are managing the cows for reproduction.
Wiltbank 1961

28. Nutrient Priorities in Cattle

29. Energy/Lactation Cycle
Energy (mcal/day)
Dry off
Lactation trimester
*Coppock: Vet Med 1990
Parturition
Energy for milk + maintenance
Body energy stores
Feed energy
This graph shows the energy needs for milk and body maintenance, the feed short fall and the loss of body energy stores that take place at peak lactation.
This peak lactation comes approximately 85 days post calving. If a cow is to cycle and settle to have a calf the same time next year as this year, she has to stabilize her bodyweight right at peak lactation.
It’s at this point where anything that affects the cow’s ability to stabilize her weight will affect her ability to cycle and settle.
This is where even a small parasite burden can affect conception.
Parasites, by their very presence, affect the cow’s immune system. In effect, the cow has her immune system constantly revved up. The cow’s immune system recognizes that parasites are present, but it can’t get rid of them. The immune system keeps trying and trying, setting up a cascade of events that results in a suppressed appetite. 1 2 3

30. Parasitism Has a Lasting Impact
Deworming improves the onset of puberty and may increase later milk production1
Lost weight-gain due to parasitism in the first grazing season persisted in subsequent seasons2
1 Perri, Gastrointestinal parasite control during prepuberty improves mammary parenchyma development in Holstein heifers, Vet Parasitol Dec 6;198(3-4):345-50
2Larssonet al.(2011), Parasite control in pasture-grazed dairy cattle: Are we at the edge of a precipice?. Available from:
Lifetime productivity of females starts from the onset of puberty
Influenced by subsequent events like age at first calving
Product of prepartum nutrition, reflected through body condition score (BCS)
Diskina, Theriogenology, Managing the reproductive performance of beef cows, Volume 86, Issue 1, 1 July 2016, Pages
Parasites in first year or two of a heifer’s life may have lasting impacts on future productivity in the herd Charlieret al. 2009
Parasite losses may include reduced milk production; lower weaning weights; delayed puberty and decreased fertility in replacement heifers; lower pregnancy rates in mature cows; and reduced feed intake, reduced feed efficiency and immune suppression in all classes of cattle.
Internal Parasite Control in Beef Cattle, Revised by Lee Jones, Assistant Professor and Veterinary Field Investigator, UGA College of Veterinary Medicine Original manuscript by James E. Strickland, Retired Extension Veterinarian, 2012

31. Evaluation of long-acting moxidectin and ivermectin in the development of replacement beef heifers 1. Started with “the best” weaned replacement Angus 2. Cydectin LA, Ivomec +, Control 3. Grew them, bred them, calved them out, and then weaned their calves

32. Strongyle EPG (GM)
Treatments Applied

33. Gain summary (lbs, LSM) d 0 - 433
Treatment Group
Mean Total Gain
Mean ADG
% Improvement over Control
Cydectin® LA
520a
1.21a
10%
Ivomec® Plus
502a
1.17a
6.5%
Control
469b
1.08b --
a,b Means in same column with unlike superscripts are significantly different (P < 0.05)

34. % Pregnant at 63 days

35. Calf Performance (lbs.)
Initial Treatment Groups
Cydectin® LA
Ivomec® Plus
Control
P value
(Pr > F)
Birth Wt.
66.4
65.3
61.5
0.36
Adj. Weaning Wt.
482a
468ab
439b
0.016
ADG (lbs/day)
1.74a
1.66ab
1.57b

36. 1. Farm A & B “Parasite Profiles”:
Farm Profile
A · History of routine parasiticide Rx
· Low stocking rates
· Improved pastures
· Low egg counts from calves
B · No routine anthelmintic practice
· High stocking rates
· No pasture (weed) improvements
· High egg counts from calves

37. Study design: Calve out all cows
(130 and 33 pairs [farms A + B])
Treat every other mother cow (within 2 weeks of calving)
Weigh calves at treatment day
Weigh calves 90 days later
Periodic egg counts

38. Cow-calf, mother cow treatment 90-day BW gains of Rx-cow calves over control-cow calves
Farm A
(Low Worm)
Farm B
(High Worm) 38

39. Generic vs branded comparison

40. Study design 6 groups of calves with 7 in each group
Branded IVOMEC, 4 generics and one negative control
Trial lasted 56 days
Cattle were grazed as one group on 45 acre heavily contaminated pasture
Measured FECR with coproculture and ADG instead of just FECR

41. Results

42. Results in ADG of each treatment group
Product Used
Average Daily Gain in pounds/day
Cooper MEC
1.21
Ivermectin Pour-On
1.28
Top Line
1.30
Negative Control
IVERCIDE
1.36
IVOMEC
1.42

43. Milligrams per kilogram of body weight
Year of Introduction of Anthelmintic Compounds
1000
100 10 1
0.1
1940
1950
1960
1970
1980
1990
2000
Year of Introduction
phenothiazine
organophosphates
Milligrams per kilogram of body weight
thiabendazole
pyrantel
morantel
tetramisole
levamisole
oxfendazole
doramectin
abamectin
eprinomectin
ivermectin
moxidectin

44. Three Primary Drug Families
Benzimidazoles
Fenbendazole
Albendazole
Oxybendazole
Nicotinics
Levamisole
Morantel
Pyrantel
Macrocyclic Lactones
Ivermectin
Doramectin
Moxidectin
Eprinomectin

45. The “trail” from allo-grooming after topical parasiticides (Bouquet-Melou et al Int. J. Parasit. 34: )
• 2 animals each as control, DRM, IVM and MXD
• Poured and then pastured together as one group
• Results after 7 days……………
Each control had plasma levels of DRM, IVM and MXD
Controls had 2-28% of a ML full dose
5 of 6 non-DRM cows had 2-21% of a full DRM dose
5 of 6 non-IVM cows had 2-17% of a full IVM dose
3 of 6 non-MXD cows had 3-11% of a full MXD dose

46. Thank you!
Bye-Bye
/// Bayer 16:9 Template 2010 /// November 2017