The Use of Controlled Grazing and two Herbal Treatments to Prevent Parasitism in Sheep and Goats

Final Report for OS07-039

Project Type: On-Farm Research
Funds awarded in 2007: $14,967.00
Projected End Date: 12/31/2007
Region: Southern
State: Arkansas
Principal Investigator:
Dr. Ann Wells
Heifer Ranch
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Project Information


Controlled grazing produced good results for prevention of parasites in small ruminants. For one goat producer, this management change was all that was needed to completely eliminate parasitism in his herd, which increased his profits. A liquid garlic preparation had less effect in two sheep flocks than chemical anthelmintics, but not by much. No treatment was very effective in these two flocks but this was due to excessively high rainfall. When controlled grazing was better implemented by these two producers, new cases of parasitism decreased. Papaya seeds had some positive effect but no decreased in fecal egg counts were seen. Chicory also showed some benefit but livestock were not on it long enough at one time to get definitive results. These two treatments needs more research which will be carried out in Phase II.

Project Objectives:

There is no single answer, as producers have been accustomed to using chemical anthelmintics. Instead, producers must use a multi-pronged approach. Controlled or management intensive grazing provides a good management strategy for preventing parasitism in many sheep and goats. Grazing forage at a height that provides optimal nutrition also keeps livestock from ingesting high levels of parasitic larvae. Weather plays a role and rain events need to be monitored to determine rotations of livestock to prevent grazing pastures with high larval numbers due to moist conditions. Certain pasture plants have anthelmintic properties. How often and for how long livestock need to graze on these plants remains to be fully determined. Selecting for animals who exhibit a high level of resilience, being able to produce and perform even with internal parasites, has to be carefully done. Mixed species grazing helps to break parasite life cycles of both livestock species. Some herbal remedies appear to have an effect but dosages and frequencies of treatment are unknown.

This project will address all of the above approaches. The sheep flock at Heifer Ranch has been rotationally grazed using controlled grazing techniques for three years. The rotations have been based on forage height, animals’ nutritional needs and presumed parasitic larval pasture contamination. Cattle have been grazed after sheep to help break the parasite life cycles. Chicory (Cichorium intybus) has been planted in one pasture as an anthelmintic treatment though grazing. A garlic juice preparation has been given to predetermined group of sheep for the purpose of determining changes in fecal egg counts and weight gains. This same garlic juice preparation has been given to sheep that have shown signs of parasitism, based on fecal egg counts, FAMACHA eye test scores and other clinical signs. Papaya seeds have also been given as a treatment following garlic juice treatment. This treatment has shown some astonishing results. Rainfall data have been recorded and plotted over the last 3 years. Each year has been vastly different but we have not changed our pasture rotations due to rainfall.

Our goal is to have no clinical cases of parasitism in our sheep. But since that is very difficult to achieve given our climate we want to have some natural, non-chemical anthelmintics we know will work. Because of our success with our grazing management and the results of the garlic and papaya, we feel that these approaches can provide sheep and goat producers with some effective control measures.


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Materials and methods:
  • Heifer Ranch:

    Katahdin ewes (n = 61) lambed in March
    Lambs (n = 96) grazed with dams on rotationally managed cool season forages (vetch, chicory, clovers) then warm season grasses, clover, and broad leaf forbs at the Heifer Ranch, Heifer International, Perryville, AR
    One group of ewes and lambs (n = 28) grazed chicory for 7 of 28 d monthly
    Lambs weaned at 120 d of age
    Lambs dewormed with COWP, Garlic Barrier, or papaya seeds
    Lambs dewormed if FAMACHA score >3

    Anthony farm:
    Diversified 35 ac crop and livestock, Marianna AR
    Boer X goats (n = 29) and their kids
    Grazed alternately with 28 cow-calf pairs
    Rotated goats every 7 days to new pasture
    Pastures mixed grass or gleaned crop fields
    Goats dewormed with papaya seeds or ivermectin/levasole mix.
    Goats dewormed if FAMACHA score > 3.

    Stiles farm:
    10 acres, Wagoner OK
    Katahdin and Dorper ewes (n = 30)
    Katahdin and Dorper lambs (n = 10), of varying ages
    Beginning rotational grazing system on diversified grass and legume pasture.
    Sheep dewormed with Garlic Barrier or Ivermectin
    Sheep dewormed if FAMACHA score > 3.

Research results and discussion:

Heifer Ranch:

n = 3 dewormed with COWP (0 – 70% reduction)
n = 3 dewormed with garlic (48 – 95% reduction)
n = 3 dewormed with papaya (0 – 100% reduction)
18% of lambs required deworming (17 lambs or 19 treatments; 10 samples not examined for FEC reduction; 2 lambs required two treatments)
No effect of grazing treatment on FEC or FAMACHA score
11 deaths: 5 related to parasites, 6 ?
Death losses similar between grazing treatment (chicory, 6.3%; control rotational, 11.9%; P = 0.18)

Sire effects detected for FEC (sire by date, P < 0.001)
Sire effects detected for FAMACHA score (1.88, 1.70, 1.70 ± 0.6; P < 0.04)

FEC increased over time until August, then decreased; no differences between grazing treatments
Too few animals dewormed to detect differences among deworming treatments.

Our goal was to see what could be accomplished with controlled, rotational grazing. Having too few animals to adequately test the alternative therapies was our ultimate goal.

Anthony farm:
Only 2 goats had Famacha scores > 3
One treated, with papaya
No other goats treated

Rotation, grazing with cattle and low stock density kept parasites problems low

Stiles farm:
All but 2 sheep were treated, either with garlic or chemical dewormers. The sheep were new to the farm and it became apparent that there was multiple anthelmintic restatant parasites in these sheep. Due to this, so chemical treatments were changed twice during the course of the summer.
8 of 25 sheep in the control group died.
12 of 25 sheep in the garlic group died.
Sire effect was present.

There was very above average rainfall at the farm in the summer of 2007 with 21 of 30 days in June getting measureable rainfall. Grass was grazed too close til 7/7 when sheep were moved to taller grass and maintained on taller grass for the duration of the study. Death losses decreased dramatically and treatments leveled off. While it didn't seem the garlic did a good job, with the excessive rainfall, no treatment was very successful.

Participation Summary

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

A field day was held at Heifer Ranch in November 2007, with the participating farmers presenting about their farms. Forty people from 7 different states were in attendance.

Presentations about this project have been made in MN, WI, and OK. Information from this project has been presented in TN, LA, VT, NY, MO and AR.

Articles written about this project have appeared in the Common Grounds newsletter and the Northeast Organic Dairy Producers Association newsletter.

Project Outcomes

Project outcomes:

The participating farmers in OK were very pleased with what they learned, even with their death losses. They continued to use the garlic after the end of the trial and are involved with Phase II of the trial. They are also strong advocates of controlled rotational grazing and will continue that from now on.

The Anthony farm in AR saw the advantages of rotation and will continue that management strategy.

At Heifer Ranch, rotational grazing will remain the main strategy, along with the use of alternately grazing cattle on pastures. The death loss from lambs on the chicory was less than those not on chicory, so chicory will be tested further.

All involved in this study are determined to reduce the need for any dewormer but continue to be interested in finding viable alternatives as the resistance level to the chemicals has increased to the critical stage.

Economic Analysis

There is no risk involved with implementing a controlled grazing system. Learning how to manage it takes some time, but at no risk to livestock. Temporary polywire fencing runs in the range of 3-4 cents per foot, which is the main cost for implementing such a system. However, the increased production of livestock, the better utilization of pasture and the decrease in the need of medical treatments for parasitism far offsets this cost.

Puna Chicory is best planted into a prepared seedbed in the fall and requires 6 months before being tall enough to graze. Barenbrug Seeds sells this seed. The cost of seed in Arkansas and the surrounding states is $60/11lb bag with a seeding rate of 1-2/lb/ac.

The cost of the alternative treatments compared to the chemical deworming treatments is as follows:

Garlic Barrier: $1.24/ds
Papaya seeds; $3.00/ds
Cydectin pour-on: $1.05/ds
Levasole: $0.30/ds sheep
$0.45/ds goats

Farmer Adoption

Given the number of presentations by the PI on this project and the questions about setting up a grazing system and the use of chicory pasture and other alternatives, there is the potential that this information has been or will be adopted by several hundred producers.

Producers need to have a grazing system in place as well as select animals, both male and female who show resistance or resilience to the internal parasites. Frequency of rotation is dependent on the geographic location of the producer. In the South, it appears that a 2 day rotation significantly lessens the incidence of parasitism in the small ruminants.

During high rainfall periods, producers will have to be especially vigilant to keep losses low. FAMACHA scoring is an essential tool to determine level of paratism (Haemonchus) in sheep and goats. Monthly FAMACHA scoring during the parasite season is a minimum and in high rainfall times, weekly scoring may be necessary.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.