Evaluation of the Activity of Plant Extracts in Boer Goats

M Worku,R Franco,J.H Miller

doi:10.3844/ajavsp.2009.72.79

Abstract

Problem statement: The effect of extracts from Neem (Azadirachta indica), Wormwood (Artemisia absinthium) and Tobacco (Nicotiana tabacum) with added copper sulfate, on female Boer goats infected with gastrointestinal parasites (GIN) was evaluated. Approach: Following initial screening for infection, animals were artificially infected with a mix containing approximately 80% Haemonchus contortus and 20% Trichostrongylus spp. After 21 days, fecal samples were collected to determine the fecal egg count. Plant extracts (200 mg kg-1 body weight) in sterile distilled water were administered on day 28. Treatment I was a control without anthelmintic (distilled water); treatment II received Neem leaf extracts; treatment III received an extract prepared from Wormwood leaves, flowers and roots; treatment IV received Tobacco leaf extracts with copper sulphate. Body Weight (BW), Fecal Egg Count (FEC), Packed Cell Volume (PCV), Total White Blood Cell Counts (TWBCC) and White Blood Cell Differential Counts (WBCDC) were determined in goats once a week, for a 4-week period. Results: There was no difference in FEC among the groups. The results showed that the plant extracts at the tested concentration were not effective anthelmintics; The PCV of the control group was significantly higher than all treatment groups (p≤0.05). Groups treated with Wormwood and Tobacco copper sulphate had dramatic decreases in PCV which may be an indicator of toxicity from these treatments. Significant differences in BW were observed between the control group and that of the Tobacco-copper sulphate group (p≤0.05). Low concentrations of Tobacco-copper sulphate treatment enhanced body weight. The extracts tested were not effective in reducing the levels of TWBCC. Circulating eosinophil counts, TWBCC and FEC, were negatively correlated with PCV in goats in this study. Conclusion: Aqueous extracts containing water soluble proteins from Neem, wormwood and tobacco are not effective anthelmintics in goats. Further investigation on efficacy and toxicity of copper supplementation on animal health and performance in goats for use by producers is recommended. Genetic variability among goats may influence the response to plant extracts. These studies support the observation that the efficacy of plant based anthelmintics is influenced by the method of extraction and host genetics in goats.

Highlights

Gastrointestinal parasites pose the greatest challenge to goat health and production in humid areas[27,29]
A comprehensive natural alternative anthelmintic management program that includes the use of plants as a cheaper and sustainable alternative to synthetic drugs would result in beneficial health and economic impacts on the goat industry
The anthelmintic properties reported have varied as a result of variations in source of plant material, season and environment variability, extraction process and host species[2,7,10]

Summary

Introduction

Gastrointestinal parasites pose the greatest challenge to goat health and production in humid areas[27,29]. The prevalence of anthelmintic resistance is a serious constraint to goat production globally[16,20,22]. The use of sustainable, integrated parasite control systems, using scientifically proven non-chemical methods and limited use of drugs is being considered to insure animal health and food safety[41]. A comprehensive natural alternative anthelmintic management program that includes the use of plants as a cheaper and sustainable alternative to synthetic drugs would result in beneficial health and economic impacts on the goat industry. Studies show that plant species can effectively reduce the degree of parasite infestation in livestock and are promising alternatives to conventional anthelmintics[2].

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Conclusion