Efficacy of pour-on dewormers on weight gain and fecal egg count in Hawaiian stocker cattle Jonathon Beckett 1, Tim Richards 2, Craig Reinemeyer 3 1 Animal.

Efficacy of pour-on dewormers on weight gain and fecal egg count in

Hawaiian stocker cattle

Jonathon Beckett1, Tim Richards2, Craig Reinemeyer3

1Animal Science Department, Cal Poly State University, Kahua Ranch2, East

Tennessee Clinical Research3

What is a Parasite?

The Random House Dictionary defines it as an organism that lives on or within a plant or animal of a different species, from which it obtains nutrients.

Parasites of ConcernBunostomum phlebotomum (Cattle Hookworm)•Causes itching of the leg and feet• Irritate stomach and intestines• Feed on blood in the intestinal wall• Causes bloody, tar colored diarrhea

Fasciola hepatica (Common Liver Fluke)•Live in the bile ducts of the liver, and gallbladder• Animals experience anemia and decreased growth• Usually results in condemnation of the liver at slaughter

Strongyloides papillosus (Intestinal threadworm)•Most common in young calves• Causes intermittent diarrhea, loss of appetite, and weight

Parasites of ConcernCooperia spp (Cattle Bankrupt worm)•Lives in the Small Intestine•Animals exhibit poor utilization of feed, taking a long time to reach market weight

Ostertagia ostertagia (Brown Stomach Worm) •Affected cattle not only lose weight but often die• Cells damaged by the parasite are replaced by rapidly dividing cells that lack function•The most commonly found and economically important internal parasite

Toxocara vitulorum (Large Roundworm)•Live in the Small Intestine• Found especially in warm climates• can travel through the lung and cause pneumonia• Compete with host for food , causing diarrhea and weight loss

Clinical Parasitism

Diarrhea

Anemia

Rough hair coat

“Pot bellied” appearance

“Bottle jaw”

Less common

Subclinical Parasitism

Decreased milk production

Poor performance

More susceptible to disease

Infertility

Unthrifty

We Deworm Cattle For Only One Reason

FOR THE MONEY

Benefits of Deworming

Increased productivity

Increased efficiency

Better immune status

Increased breeding efficiency

Reduced pasture contamination

Importance of fecal egg counts?

Most commonly used technique Usefulness depends on its precision

and accuracy Requires knowledge of parasite biology

in area, experience with levels that are indicative of economic impact in a given situation

Importance of Larval Cultures

Very few parasitologist are able to differentiate between different genera of the parasite eggs

Nematodirus is only “easy one” Larval cultures let eggs hatch then the

worms are identified

Macrocyclic Lactones

Avermectins– Ivermectin (Ivomec)– Doramectin (Dectomax)– Eprinomectin (Eprinex– Look alikes– Generic

Milbemycins– Moxidectin (Cydectin)

Types of Administration

Injectable– Advantage – Easy to

administer– Disadvantage – Can create

problems in the meat– Disadvantage – Must be re-

dosed every 60 days

Pour-On– Advantage – Very quick to

administer– Advantage – Noninvasive

administration– Disadvantage – Must be re-

dosed every 60 days

Drench– Advantage – Very quick to

administer (not as quick as Pour-On)

– Disadvantage – Must be re-dosed every 60 days

– Disadvantage – Cow can spit out most of the product

Bolus– Advantage – Dosed only once in

the cow’s life– Disadvantage – Much longer

administration time– Disadvantage – Administration

requires training

Hypothesis

The effective drug in pour-on dewormers will affect growth and parasite infection throughout the grazing season in stocker cattle.

Control

Ivomec

Eprinex

Dectomax

Cydectin

Protocol

A

B

C

D

E

126 330

Transported by boat to Canada

-60

Transported to Feedyard,

Bruneau, ID

Transported to Swanton

Pacific Ranch

-14

Harvested at IBP,

Boise, ID

-21

Dewormed with

Dectomax

Days

0

Dewormed

70

Redewormed

Redewormed

156

Average Daily GainDay 0-105

0

0.5

1

1.5

2

2.5

Cydectin Dectomax Eprinex Ivomec Control

a a a ab

Average Body WeightDay 105

480

490

500

510

520

530

540

Cydectin Dectomax Eprinex Ivomec Control

+32.8 +31.6

+36.1

+27.6

Total Fecal Egg Count

0

50

100

150

200

250

300

350

0 28 70 105 131

Day of Study

EP

G

Cydectin

Dectomax

Eprinex

Ivomec

Control

Fecal Egg Counts Days

Treatment 0 28 70 105 126

Cydectin 0.7 4.8b 39.2b 1.6c 12.9c

Dectomax 0.8 15.6b 75.2a 2.1c 11.2c

Eprinex 2.0 1.1c 54.2ab 7.4b 21.2b

Ivomec 0.7 1.1c 86.0a 5.6b 13.8bc

Control 1.7 292.1a 57.9ab 40.2a 45.5a

ab Numbers with differing superscripts within a column differ significantly (p<.05)

RedewormedDewormed

Carcass Weights

670

675

680

685

690

695

700

Cydectin Dectomax Eprinex Ivomec Control

Yield Grade

3

3.1

3.2

3.3

3.4

3.5

Cydectin Dectomax Eprinex Ivomec Control

Backfat

0.5

0.52

0.54

0.56

0.58

0.6

Cydectin Dectomax Eprinex Ivomec Control

Ribeye Area

11

11.2

11.4

11.6

11.8

12

Cydectin Dectomax Eprinex Ivomec Control

a

ab abab

b

Marbling Score

695

700

705

710

715

720

725

730

735

Cydectin Dectomax Eprinex Ivomec Control

Yield Grade 1 & 2’s

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

Cydectin Dectomax Eprinex Ivomec Control

What does this mean?

It is important to deworm Eprinex and Cydectin equally resulted

in maximal growth Ivomec is the weakest against internal

parasites Without adequate forage, no dewormer

is fully effective

What does this mean?

Effect of dewormer during stocker phase is not significant at slaughter but effects are visible– Take advantage of cheap gain during

stocker phase rather than pay more for the gain in the feedyard

What does this mean?

Other factors must be considered when selecting a dewormer– Cost– Persistency of Protection– Ease of Administration– Rain Fastness– Flame Resistance– Customer Service

Acknowledgements

Kahua Ranch – Thank you for allowing Cal Poly to conduct the trial on their cattle

Bruneau Cattle Company – Accommodating the feedlot phase

2001 Swanton Pacific Stocker Enterprise group for participating in the data collection and organization of the trial

Brian Wetzel – Cal Poly Alumni for initiating this line of research as his senior project