Major Ectoparasites of Small Ruminants in Arsi Zone of Oromia Region: Prevalence, Species Composition and Acaricidal Efficacy of Medicinal Plants Against Lice of Sheep
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Date
2010-03-10
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Addis Ababa University
Abstract
A study on major ectoparasites of sheep in three selected agro-ecological sites of Oromia Region, Ethiopia showed 81 .5% overall prevalence of ectoparasites. The ectoparasites recorded were lice (75.5 %) Damalina ovis (67.1%), tick infestations (23.8%), Linognathus ovillus (14.6%), Melophagus ovinus (5.65%) found only in mid and highland, psoroptic mange 1.0% and sarcoptic mange 0.3% were the major ectoparasites. The major ectoparasites identified Damalina ovis, ticks and M. ovinus were showed statistically significant difference (P<0.05) of prevalence in high and midlands and L.ovillus in the lowland. The risk of Damalina ovis infestation in highland (OR) =2.2, (P<0.05)) was two times higher than in the lowland. Agro-climate, age and BC in Damalina ovis infestations are found to be the risk factors for the difference of prevalence of ectoparasites: agro-climate (OR=2.22), (P<0.000), age (OR=1.S), (P<0.031) and BCs
(OR= 1.09), (P>0.05). Favorable climatic conditions, backward level of management, poor level of consciousness and awareness of farmers, and weak animal health extension services are believed to have contributed for widespread distribution and occurrences of ectoparasites. The growing threat of ectoparasites to small ruminant production and tanning industry needs a well growing threat of ectoparasites to small ruminant production and tanning industry needs a well coordinated program. The in-vitro efficacy of 20 mg/ml, 40mg/ml, 80 mg/ml and 160 mg/ml solutions of fixed oil extracts of Jatropha curcas, Melia cafra, Ximenia azadrachta. Pyrethrum cinerariifolium and Nicotiana tobacum and 0.625%, 1.25%, 2.5% and S% solutions of Cybopogon citratus and Eucalyptus globulus essential oils extracts were performed after 10 min, 30 min, 1hr, 2hrs, 3hrs, 6hrs and 12hrs in all tests using usual and strict criteria for mortality. From seven herbal plants' extracts four of them were showed statistically significant difference (P<0.05) against Linognathus ovillus: Jatropha curcas and Melia azedirachta at 160, 80, 40 and 20mg/ml, Cymbopogon citratus and Eucalyptus globulus at 5 % and 2.5% concentrations at 12 hours. Six of the seven herbal plants' extracts were showed statistically significant difference (P<0.05) against Damalina ovis: Jatropha curcas, pyrethrum and Ximenia calra at 160mg/ml, Melia azedirachta at 160, 80 and 40 mg/ml, Cymbopogon citratus and Eucalyptus globulus at 5 % and 2.S% concentrations at the end of 12 hours when compared to the commercial acaricide 0.1 % diazinone 60 EC. For therapeutic efficacy study (iv-vivo) in biting/chewing lice /Damalina ovis /40 sites per animal were examined before and after treatment. Lice were counted in five predilection sites /neck, shoulder, wither, flank and rump/at eight partings in each sites in an area of ten centimeters in length. During in an in-vitro test on Damalina ovis with 2.5% Cymbopogon citratus and 5% Eucalyptus globulus, there were statistical significant differences (P< 0.05) in louse count between treated and negative control groups. No apparent signs of any local or general adverse effects were observed during the study after the application of the extracts. The percent louse count reduction obtained was < 95% efficacy and never greater than 88. 11 % in an in-vitro test in the current study against Damalina ovis. Despite the current in-vivo study's lower results, traditionally claimed herbal plant extracts can be a good substitute for the synthetic compounds if there is a further increase in resistance to the acaricides in use and further studies carried out on synergism of two or more potent plant extracts. The licidal potent of Melia cafra fixed and Cymbopogon citratus essential oils for instance, suggest that they may find an application in the future. These results demonstrate the possibility of using traditional claimed herbal plant extracts for lice control.
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Keywords
Ectoparasites, efficacy, in-vitro, in-vivo, lice, Oromia region, prevalence, Sheep, traditional herbal plants