Indigenous Knowledge and Diversity of Ethnoveterinary Plants of the Study Area
The present study showed the rich knowledge of ethnoveterinary medicinal plants in Dawuro zone that was indicated by the number and diversity of plants reported. The results showed that there was no difference in the average number of plants reported either by female or male respondents indicated both men and women members of the community have good knowledge on medicinal plant use. This finding is disagrees with other studies conducted in the country [30, 31, 32] who observed that men had more knowledge of plant usage because they are naturally selected during childhood to be apprentices of ethnoveterinary practices. In this study, the knowledge regarding the treatment of animal ailments did not show any difference between the age groups. In other studies, however, it was observed that the number of medicinal plants reported was increased with age, and the older informants reported more medicinal plants than younger individuals [17, 31, 33, 34]. This could be related to a higher degree of cultural contact and experience of the elderly members with curative plants than that of younger members in the community.
The findings also showed that educational level is considered as a factor to determine the inheritance of indigenous knowledge, and conservation and sustainable use of medicinal plants. The indigenous knowledge regarding the treatment of animal ailments did show significant difference between levels of education. Illiterate informants reported significantly more medicinal plants than literate members. This might be oral transfer, influence of modernization and technological changes, and lack of curiosity by educated generations to acquire indigenous knowledge like their fore parents. This finding is in agreement with the previous studies of others in Ethiopia [35] and other world [26, 36] who reported as majority of informants are illiterate while only few of them reached the high school diploma level.
Oral transfer and secrecy on acquisition of knowledge on ethnoveterinary practices within the study districts, most of the time-tested indigenous knowledge of the traditional herbalists passes away might also explain the decline of indigenous knowledge going down the generation ladder. This result agrees with other findings in Ethiopia [13, 34, 37, 38] and elsewhere in other countries [1, 33, 39, 40] share a similar concern on the knowledge gap down generations in different cultural groups.
According to informants, livestock keeping is one of the most important economic sources of rural community of study area as a major support to their livelihoods, crop production, transport, and for generating income to sustain life. The farmers of the area not only depend on plants to get fodder for their animals but also use different medicinal plants to treat various animal diseases. Results of this study showed that people in the Dawuro zone have longstanding indigenous knowledge on the use of medicinal plants to treat various livestock ailments. The deep-seated culture of plant use for successive generations might have played the role for a sentimental adherence of the community to ancestral medical traditions which are still held as highly valued heritage of the society.
The number and diversity of medicinal plants reported by informants revealed the rich traditional ethnoveterinary knowledge in Dawuro zone and the number of medicinal plants reported is more than the studies conducted in Ethiopia and other different parts of the world [2, 10, 13, 41, 42], in Brazil [17], South Africa [43, 44], Pakistan [26, 45], and India [46, 47]. The millennia-old interaction of indigenous people in the area with in the vicinity available medicinal plants might have enabled them to develop an indigenous knowledge system best fit to select and use diverse curative medicinal plants to treat frequently occurring livestock diseases. The studies of [31] stated that knowledge on plant use is the result of many years of human interaction and selection on the most desirable and successful plants present in the immediate environment at a given time.
The present study revealed that best representation of ethnoveterinary species of family Asteraceae with 13 species has the highest species followed by Fabaceae, Lamiaceae and Euphorbiaceae, respectively in the study area. The wider utilization of this Asteraceae family might be due to its plenty in the study area or high bioactivity [26]. This finding was however different from that of [41, 48] who in an ethnoveterinary survey reported Solanaceae and Fabaceae family respectively the first level use. The difference among study might be related to the different dominant vegetation of the areas or might be associated with traditional beliefs of different cultures in using traditionally specific plants.
Growth Habit, Source and Parts of Ethnoveterinary Plants Used
The present finding showed that the most commonly used medicinal plants habit in the study area are utilization of herbs followed by trees in treatment preparation. The present finding was in contrast with other investigators [37, 49-52] who reported dominance of shrub species for ethnomedicinal preparation in Ethiopia. The variation might be related to different ethnolinguistic groups in the country could be attributed to the wide agro-ecological diversity and specific indigenous knowledge of different communities.
Results also revealed that the dominant practice of harvesting majority (56.2%) of ethnoveterinary plants of Dawuro zone is from wild sources. This would indicate the degree of anthropogenic pressure exerted on wild plant resources of the area. Overdependence on wild resources together with reduction of the wild resources due to ever-increasing population pressure poses a threat to medicinal plant riches of the area. Comparable trends in overharvesting medicinal plants from uncultivated sources were also reported in other parts of [30, 31 37, 38, 53, 54], and in another place in Pakistan [45, 55], and Brazil [17]. In this study, the communities have less effort to cultivate medicinal plants in their home gardens and agricultural field rather, they go to nearby or far places and collect the plants.
The finding showed that leaves to be the most harvested plant parts followed by roots in the treatment preparation. This finding is in line with the results of other ethnomedicinal studies [17, 56-60].The first line choice of leave might be associated with traditional beliefs in communities about no difficulty of collection, preparation, and the main site of photosynthesis and are involved in a variety of physiological processes of plants and produce numerous secondary metabolites that could be a possible reason for their effectiveness and efficacy against animal health problems.
Livestock Ailments, Treatment Preparation and Traditional Diagnostic Methods
Identification of specific livestock ailment types in the area was found to be made based on indigenous knowledge on symptoms and corresponding livestock illnesses held in the memories of local people. Similar was found true in selecting medicinal plants which were thought to be most appropriate to manage different veterinary health problems.
Results also showed that leech infestation (4.6%) is one of a challenge to livestock health in the study area during winter (Bega) and spring (Tseday) seasons. This might be related to have an annual life cycle of leeches. They breed in the spring; young leeches develop and mate in the spring of the following year. In addition, adult leeches can live for as long as 18 to 27 years [61]. On the other hand, traditional healers argued that reduction of different fresh water bodies (rivers and streams) in amount during dry season has low pressure that could not washed out leeches from water bodies which make favorable condition for multiplication. Thus, traditional healers use remedial plants to control leech infestations.
The dose administered often varied with the parts of the plant used and the methods of preparation. In this study, the majority of the treatments are taken orally as also reported earlier in other parts of Ethiopia [31, 52, 62]. In addition, the majorities of herbalists administer the preparations once or twice daily for three days or keep treating until the animal recovers if the disease is not acute like blackleg. The traditional herbalists have a clear understanding about the occurrence of certain outbreak diseases from other endemic diseases mainly characterized by lameness and shivering according to those interviewed (blackleg). In fact, this disease mentioned present in higher number or the symptoms are more noticeable. Based on distinctive clinical symptoms that sick animals shown, they immediately search for solutions to treat their animals. Full recovery is confirmed when the animals resume feeding and other physical activities. If animals do not respond to the treatments, they search for other alternatives like modern drugs.
Furthermore, treatments are given to the domestic animals with different vehicles like water, seed, flour, milk, and so forth, in the area. The use of these vehicles might be due to their enhancing potential of taste and medicinal properties of certain plant remedies. Physical manifestation of the diseased animal and visually confirmed degree of severity of illness are used to determine preparation doses to treat livestock ailments. Some traditional practitioners used a various unit of measurements such as plastic jugs, glasses, bottles, cups, syringe, and gourd locally called “Buliyaa” to measure dosage for remedial preparations while others reported to use a handful or counting like Solanum anguiv anguivi Lam. However, there is no strictly standardized dose of herbal preparations as known for modern veterinary medicine was reported by traditional healers for any of the preparations used to treat livestock ailments in the area. The same findings were also reported from other studies conducted at different parts of the world [17, 26, 45, 60, 63] who reported the lack of standardized doses in traditional prescriptions of livestock traditional medicine. The lack of precision and standardization has been cited as one of the most important shortcomings of the traditional healthcare system in Ethiopia [8, 31, 64, 65].
Due to lack of standardized doses of herbal preparations, traditional practitioners observed some symptoms of side effects of herbal preparations on their animals in the study area like shock and lacrimation. For instance, if high amount of Azadirachta indica and Solanum anguiv anguivi Lam. administered might cause noticeable side effects. However, no death cases were reported by the informants because they use different traditional antidotes like drinking and sprinkling cold water immediately to the body of animals especially head region, milk, porridge and the end product of traditional kocho fluid “Zaalima” to manage plant side effects.
The observed diverse medicinal uses of plants in the area against various livestock ailments indicates presence of inherent curative property engraved within each medicinal plant which still plays an essential role for the production of relatively healthier cattle, sheep, goats, equines, chickens and dogs. The relatively high number of medicinal plants cited for treating cattle ailments may also be related to occurrence of more diseases affecting cattle populations in the area. Presence of largest use of ethnoveterinary plants for treating cattle ailments was also reported for other cultural groups in the country [31]. Two plant species: namely Sida scimperiana and Artemisia annua L. are used for treatment of rabies in dogs. The utilization of relatively few medicinal plants for treatment of poultry, equines and dogs might be associated to the low perception, low occurrence of diseases affecting and low ethnoveterinary experiences of herbalists on these species. In the same way, the highest percentage of medicinal plants used to treat infectious diseases in the study area could also be related to high occurrence of such diseases in Dawuro zone. This was justified by presence of highest number of infectious diseases (accounting 63.4% of livestock ailments in the area) reported by informants. Furthermore, this study also revealed that traditional veterinary practices in the area are well focused to the most prevailing health problems.
The method of treatment preparation in many cases varied from individual to individual. The same plant materials for the same ailment are prepared in different ways by different traditional veterinary healers. Thus, traditional remedy preparation was also varied in plant species compositions. In this study, traditional healers prepare ethnoveterinary recipes mostly in the forms of pounding and homogenizing with water followed by crushing. This finding is in agreement with [31, 57, 65, 66] who reported pounding the remedial part and homogenizing it with water was found to be the major mode of remedy preparation.
Most of the recipes are prepared using single plant (93.4%) while some of the recipes are also prepared in the form of mixed two or more plants together (6.6%). Thus, the widely using of single plant species for the preparation of local medicines in the study area is in agreement with the finding of [67, 68, 69]. However, it is generally believed that potency of the treatments can be enhanced when used in concoction form described by [26].
Results of present study also showed that some plants are used to treat more than one disease, while others are used manage one ailment. The highest number of multiple ethnoveterinary uses was recorded for Capsicum frutescens (treated against 12 ailment types) and Lepidium sativum (10 ailment types each). Herbalists in the same geographical area often cite different herbal treatments for the same disease, and variations were often encountered in the method of preparation, dosing, and routes of administration. This finding is inconsistent with other ethnoveterinary studies conducted in Ethiopia and elsewhere [17, 31] who reported that Allium sativum and C. guianensis were highest number of multiple ethnoveterinary uses, respectively.
The present study showed that the claimed medicinal plants have values other than their medicinal roles. They are used by the community for different purposes such as, human disease treatment, fire wood, construction, timber production, animals’ fodder, fence, edible, spices, and other uses such as agricultural tools and soil conservation. This finding is similar to other studies from different parts of Ethiopia [41, 57, 70].
The results also revealed that few traditional herbalists (7%) preferred days and time for plant collection like on Sunday and Wednesday and at early morning without contact with any person 00000which they believe that will make the treatment more efficacies to cure diseases. Nearly similar findings were reported from Ejaji area (Chelya Woreda) in West Shoa [57] and Gimbi area, in Western Wellega [58] who pointed out medicinal plant collection and provision was restricted to and done on Sunday, Wednesday and Friday. However, the majority of traditional healers reported that there is no taboos association (93%) with medicinal plant collection and uses in the study area. This result is in line with the finding from other parts of Ethiopia [38].
Market Survey of Ethnoveterinary Plants
Marketing of medicinal plants are not common practices at the studied area. Local community mainly harvest and use ethnoveterinary plants for a private use with their own livestock. However, a limited range of buying and selling medicinal plant was practiced at Tocha, Waka, Wara, Gassa c’are and Orobi local markets in the Districts. About18 species of medicinal plants in veterinary use were showed to be accessible on the market and only 3 species i.e., Lannea fruticosa (Dechimarac’iya) and Echinops kebericho (Burssa) (0.34 US Dollar about 200-250 gm dried root material), and Pentas schimperiana (Dawuridama) (0.142 US Dollar) about 250-500 gm bunch of leaf material) seem to be purchased solely for use in traditional medical applications. The remaining 15 marketed species were mainly sold for their uses other than medicine i.e., food, spices and other purposes though they were mentioned to be occasionally used as remedies when there is a need. This was also reported in other ethnoveterinary survey [31, 71]. A few traditional healers treat sick animals sometimes free of charge if close relations exist. However, a majority of them believed that whatever relation existed, the owner had to pay money for the plants; otherwise they underlined that the medicine would not be effective.
Informant Consensus Factor, Fidelity Level, Preference Ranking and Use-value of Ethnoveterinary Plants
The observed highest informants’ consensus (ICF=0.83) on ethnoveterinary medicinal plants used to treat diseases of reproductive system followed by infectious (ICF=0.78) in the area. The findings of [26] from Pakistan and Ethiopia [66] have indicated that the highest share of similar plant use information within a community for disease of reproductive system and infectious category, respectively, while disagrees with other studies in Ethiopia [31] who reported high ICF in the gastrointestinal disease category. The recorded high plant use citation for treating ailments in the infectious disease category might also indicate the relatively high occurrence of such diseases and ease of identifying ailments and corresponding curative plants occurring in the Zone.
Highest fidelity level values were obtained for Cyphostema sp. in the diseases of reproductive system, Calpurina aurea in the ectoparasites, and Pentas schimperiana in the fattening and bone broken disease category accounts (100% each) followed by Eucalphytus globules (91.67%) in the infectious/blackleg disease category and Croton macrostachyus (90.9%) for the wound and trauma therapeutic category indicates relatively high healing potential of the species for treating ailments under the respective categories. The highest FL might be related to which the cited plants species has more healing power contributed to the presence of bioactive compounds for the respective ailments. Analysis of the preference ranking exercise also indicated that Azadirachta indica and Eucalphytus globules were the most preferred ethnoveterinary medicinal plants used to treat blackleg, the most commonly reported disease in the study area. This may be attributed to the presence of bioactive compounds against causative agents of blackleg in these species.
According to [17] the use value is a quantitative method that demonstrates the relative importance of species known locally. This method can be used to select species for cultivation in gardens or construction of medical work of scientific validation. Results of this study showed that Azadirachta indica and Eucalphytus globules were the species with highest use-value, probably because they are dominant vegetation and high curative activity one, they trust in the study area. This result is disagreement with other ethnoveterinary studies [17, 36] who reported that Carapa guianensis Aubl. and Cedrelopsis grevei were species with highest use-value, respectively. Medicinal plant species cited by more than two informants are considered as the most used medicinal plants are found by [36]. In this study, all the identified medicinal plants are cited by two and more than two informants.
Threats to and Conservation of Medicinal Plants
Although the value of indigenous knowledge in livestock disease treatment is indispensable; the local communities and government did not give due attention for conservation of traditional medicinal plants. There are different threats to medicinal plant availability and indigenous knowledge in the study area. In this study, indigenous knowledge on ethnoveterinary medicinal plants are becoming scarcer due to different threats such as agricultural expansion, unselective harvesting, overgrazing, uncontrolled bushfires, drought, deforestation, landslide, pesticide spraying, and population increase. These findings are in accordance with the reports of [10, 30, 41, 72] who noted that the major threats for medicinal plants in the different parts of Ethiopia. Among the major threats, drought is the most threating factor to medicinal plants, which is in line with finding of [72] who reported that responses of lowland agro-ecology stated that prolonged dry season is the most pressing factor followed by agricultural expansion.
The study found that there is no any support and encouragement from governmental and non-governmental organizations in conservation and sustainable utilization of medicinal plants. In addition, most of the traditional practitioners have no clear awareness on the conservation of plants with medicinal value. However, someone have home garden and on agricultural field management practices of medicinal plants conservation was practiced. It is once a year that some medicinal plants like Lepidium sativum, Maerue oblongifolia, Lannea fruticosa, Nicotiana tabacum, Piper capense, Embelia schimperi, and Echinops kebericho seed, leaf, fruit or root, respectively are harvested, dried and preserved in roof corners or outside house, and dried parts are stored in special place for further use.
Non-plant Treatments and Factors Contributing to Use of Ethnoveterinary Medicine in the Study Area
There is abundant undocumented traditional knowledge of non-medicinal plant materials used to treat various livestock diseases on study area have had a significant effect on animal health practices. The survey also revealed that eleven (11) non-plant remedies are used by the herbalists in the study area. Some of the non-plant medicinal materials reported include hyena faece, wood ash, honeydew, oils, kerosene, local soap, salt, porcupine meat, dear faece, sharp hot iron or knife, milk, fermented kocho (Ensete ventricosum), porridge and the end product of Ensete ventricosum fluid traditionally called “Zaalima” which they believed were effective in ethnoveterinary management. Nearly similar ethnoveterinary studies conducted in Nigeria [27] share a similar concern on the knowledge of non-medicinal plant ethnoveterinary practices found that sharp hot iron or branding for treatment of blackleg and inflammation due to trauma, salt used for appetite promotion, and vegetable oil for managing bloat, respectively. However, hynae feaces, wood ash, dear faeces, porcupine meat, fermented kocho (C’aalaa unc’c’a), the end product of local kocho fluid (Zaalima), and honeydew has not been reported before other ethnoveterinary survey of non-plant remedies used in Ethiopia.
According to [73] the use of animals for medicinal purposes is part of a body of traditional knowledge which is increasingly becoming more relevant to discussions on conservation biology, public health policies, and sustainable management of natural resources, biological prospection and patents. In this perspective, the present study was also undertaken to document information about local animals used in veterinary medications by traditional herbalists in the Dawuro zone. According to informants, the products and parts of porcupine, hyena, cattle, bear and aphids (insects) were used by the community in ethnoveterinary practices. Other studies have likewise highlighted these medicinal animals used in ethnoveterinary practices from other parts of the world [73, 74, 75].
The factors contributing for medicinal plants and non-plants of use as ethnoveterinary treatments, are easy accessibility, inadequate number of formal veterinary clinics and veterinarians, primary healthcare system, apparent effectiveness, lack of adequate modern drugs, long distance to veterinary clinic station, affordability and low cost, and some diseases did not respond to modern drugs available in the area that would never be enough to provide healthcare services for more than 3,543,417 livestock population. Moreover, almost all of the rural community lives in marginal areas which are not easily accessible to the rare modern veterinary services which are also known for their scorching prices totally unaffordable to the less economically endowed people living there. This finding is similar with the work of [7, 31] in the Ethiopia, in South Africa [43] and in Brazil [73].