Use of Herbs as De-wormers for Sustainable and Profitable Production of Sheep and Goats Under Natural Grazing Conditions

Final Report for LNC07-283

Project Type: Research and Education
Funds awarded in 2007: $146,522.00
Projected End Date: 12/31/2010
Region: North Central
State: Missouri
Project Coordinator:
Dr. Helen Swartz
Lincoln University
Arlene Stewart
Lincoln University
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Project Information


This project increased awareness of researchers and producers alike on the potential of natural herbs as low cost substitutes for synthetic costly chemical de-wormers of warm weather intestinal parasites of Katahdin hair sheep, Dorset wool sheep and Boer meat goats that results in many deaths of sheep and goats. The three groups of chemical de-wormers currently approved for sheep and goats by the Food and Drug Administration are experiencing internal parasites developing resistance.

Effects of natural herbs on the immunoglobulin (IgG) showed no ill effects. Sheep and goats producing meat, milk, cheese and wool consumed in this country fed wormwood (Artemisia absinthium) had a positive result when fed wormwood. The commercial ground powder of wormwood was increased four times the recommended dosage and fed to sheep and goats with no negative effects observed. Immunoglobulins (IgG) were not affected by feeding wormwood, all within the normal range, therefore no ill effects to the immune system was observed in any way as the wormwood had a positive effect on controlling parasites in sheep and goats.


The number one problem of sheep and goat producers in Missouri in the hot summer months is the blood sucking internal parasite Haemonchus contortus that sucks blood making animals anemic followed by death. Meat goats are the fastest growing commodity in Missouri. The state has 80,000 small farms with sloping land well suited for grazing with sheep and goats. Cattle, sheep and goats are commonly grazed as cattle prefer grass, sheep prefer forbs (weeds) and goats prefer browse plants. The biggest challenge to profitability and sustainability in the grazing season are the internal parasites that suck blood. Internal parasites have been commonly treated with pharmaceutical drugs such as avermectin. The parasites have developed resistance to the common drugs approved on the market today. Natural herbs such as wormwood were shown to control internal parasites in a study in Pakistan (Igbal et al., 2004). Effects of wormwood fed to sheep and goats on the immune system and the animal’s ability to overcome stomach worms needs to be researched in this country. Wormwood specie has a long history of use as a medicinal herb dating back several centuries in de-worming sheep and goats in the hot summer months. The cost of de-worming a sheep or goat is $45 using commercial dewormers compared to $4.00 to de-worm with wormwood. The effects of wormwood on the immune system measuring immunoglobulin (IgG) is important as the immune system must function to help control internal parasites.

Project Objectives:

1)To increase awareness of herbs as an alternative de-wormer compared to a commercial de-wormer, avermectin.

2)To observe the increase of recommended herbal de-wormers to monitor toxicity.

3)To measure immunoglobin IgG to determine the effects of feeding wormwood on the immune system of sheep and goats.

4)To measure weight gain or loss in A)control, B) wormwood group C) commercial de-wormer group of Boer meat goats, Katahdin hair sheep and Dorset wool sheep.

5)To observe HAMACHA compared to hematocrits on red blood cell count and anemia.


Click linked name(s) to expand/collapse or show everyone's info
  • Aaron Baba
  • Abua Ikem
  • Nsalambi Nkongolo
  • Arlene Stewart


Materials and methods:

1) A group of Boer meat goats, Katahdin hair sheep and Dorset wool sheep were reared and monitored for symptoms of intestinal parasites that suck blood and make the animals anemic. The animals were divided into groups; 1) control, 2) experimental group fed wormwood and 3) experimental group receiving avermectin, the commercial de-wormer.

2) Animals were monitored using both physical and pathological indices, change in body weight, color appearance of the gums and eyelids, hematocrits (packed cell volume), and FAMACHA© cards, a method named after its South African developer Francois Malan. Each photograph corresponds to a specific stage of Haemonchus Infection from 1 to 5, 1 being red and 5 being white.

3) Pathological indices includes measuring immunoglobulin IgG and change in fecal egg population from May to October.

Research results and discussion:

The Boer meat goats, Katahdin hair sheep and Dorset wool sheep divided into a control group, a group fed wormwood, and a commercial group given the synthetic anthelminic (SA), avermectin had results that was positive for the wormwood. The animals were stratified by body weight and age and allocated randomly to 1 of 15 groups. The natural herbal group (5.5 g/hd/d) and synthetic anthelmintic (4.5 mL/kg body weight) tended to be greater from natural herbs vs. SA (P=0.06). Average daily gains and total body weight gain) were greater from natural herbs vs. synthetic anthelmintics (P<.0.05)showing the herbs had a positive effect on weight gain. Ending fecal egg counts were greater (P<0.05) in the control group vs. natural anthelmintic (NH) showing a positive result of feeding wormwood. Fecal egg count tended to be greater from beginning to end in the control vs. the NH and SA (P<.0.05 resulting in a positive effect of both NH and SA. The immunoglobin (IgG) collected throughout a season from May to October was within the normal range in all of the three treatments. The experiment increasing the wormwood four times the recommended dosage showed no harmful effects to the animals. The comparison in performance on the IgG and gastrointestinal loads in sheep and goats showed beneficial results for controlling gastrointestinal parasites while grazing pastures in the hot summer months in Missouri. The statistical analysis was PROC MIXED SAS, experimental unit groups of animals with contrast: Means of control vs. means of natural herbs and synthetic anthelmintics. Treatment means are reported as the least squares means.

Research conclusions:

The positive impact of feeding wormwood grown in the greenhouse, cut and dried and fed weekly to sheep and goats showed the potential of wormwood for substituting for a commercial anthelmintic. Many commercial dewormers are being reported as no longer effective to the internal parasites showing resistance. Therefore, new products are needed in the sheep and goat industry to control the hot summer internal parasites that kill so many sheep and goats.

Economic Analysis

The economic analysis of $45/hd in a season to de-worm sheep and goats can be fed wormwood at a cost of $4.00/hd. The alternative product of herbs to control gastrointestinal parasites in sheep and goats is economically feasible.

Farmer Adoption

Natural herbs can be grown by farmers, cut and dried and fed to sheep and goats as recommended to help control the number of problems due to worms in the hot summer months. Recommended dosage is available and costs are low compared to commercial anthelmintics and can provide a de-wormer to those farmers who are experiencing internal parasite resistance to commercial de-wormers.

Participation Summary

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

Performance and Gastrointestinal Parasite Control by Boer Goats offered a synthetic anthelmintic or Natural herb while grazing during the Summer. 2011. ARD Conference, Atlanta, GA.

Project Outcomes


Areas needing additional study

Studies in feeding natural herbs to sheep and goat, prior, during and after breeding is needed.

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.