In this study, we have investigated ethnoveterinary medicinal plants, parts used, preparation methods, and livestock diseases treated in Ensaro district, North Shewa Zone, Amhara Regional State, Ethiopia. For the study, 389 informants (95 key informants and 294 general informants) were involved with an age range from 20–90 years. Many key informants were unwilling to disclose their knowledge particularly to show and the type of medicinal plants and to tell their names because they thought that the plant will lose its efficacy while they disclose them. But at the verge of their age, they will transfer this knowledge orally to one of their sons to whom is considered as loyal to keep the knowledge not leaked out their bloodline.
The distribution of ethnoveterinary knowledge between genders revealed that the majority of informants were men (72.3%). This is since, in most of Ethiopia, the major responsibilities of women are restricted in the home and homestead while most of the outdoor activities are performed by men which exposes them to share knowledge with others. Another possible reason might be indigenous knowledge is passed on to the son mainly to the first son. This aligns with the research result of Yigezu et al. (2014) that more than ninety percent of ethnoveterinary practitioners were male and the study carried out by Birhan et al. (2018) in Enarj Enawga District, East Gojjam Zone, Amhara Region, Ethiopia also indicated consistent finding. This indicated that indigenous knowledge is not equally distributed between gender in the country.
Concerning educational status, 48% of them were literate while 52% were illiterate. However, illiterates have been mentioned more number medicinal plants with their medicinal values than literates. This implies that education particularly modern education has negatively impacting indigenous knowledge.
The present study identified and documented 44 ethnoveterinary medicinal plants, which are used to treat 16 types of livestock health disorders in Ensaro district, North Shewa Zone, Ethiopia. This indicated that the current study area has a good status of ethnoveterinary medicinal plants and associated indigenous knowledge regardless of its vegetation cover. This may be because, in developing countries, medicinal plants have remained the most economically affordable and easily accessible source of treatment for a variety of livestock health problems (Khan et al., 2019; Adeniran et al., 2020; Dzoyem et al., 2020; Gonfa et al., 2020).
The number of medicinal plants documented in this study was comparable with similar previous studies in different parts of Ethiopia and other countries. In a study conducted in Ada’ar District, Afar Regional State, Ethiopia, 49 ethnoveterinary medicinal plants were identified, documented, and published by Giday and Teklehaymanot (2013). Similarly, another report by Tamiru et al. (2013) of the study in Dabo Hana District, West Ethiopia also showed that they identified and recorded 48 ethnoveterinary medicinal plants for treating 22 types of livestock diseases. In Ankober District, North Shewa Zone, Amhara Regional State, 51 medicinal plants distributed in 50 genera and 35 families were reported by Lulekal et al. (2014). An ethnoveterinary study conducted by Njoroge and Bussmann (2006) in Kenya showed that the Kikuyus people are using 40 medicinal plants to treat different kinds of cattle diseases. This finding demonstrated that ethnoveterinary medicines are still important in the prevention and control of livestock diseases in Ethiopia and other parts of developing countries.
Most of the ethnoveterinary medicinal plants identified and documented in this study were also be reported in previous studies conducted out in different parts of Ethiopia. Among 42 medicinal plant species documented in this study, 7 species in Enarj Enawga District, East Gojjam Zone, Amhara Region, Ethiopia by Birhan et al. (2017), 20 species at Bale Mountains National Park, Ethiopia by Yineger et al. (2007), 9 species in different selected districts of Southern Ethiopia by Eshetu et al. (2015), 9 species in Seharti-Samre district, Northern Ethiopia by Yirga et al. (2012), 16 species Ankober District, North Shewa Zone, Amhara Region, Ethiopia by Lulekal et al. (2014), 15 species in Abergelle, Sekota and Lalibela districts of Amhara region, Northern Ethiopia by Assefa and Bahiru (2018), 8 species in Leka Dullecha District, Western Ethiopia by Tesfaye and Erena (2020), 8 species in South Wollo Zone, Amhara region, Ethiopia by Wodegebriel et al. (2018) were documented. These findings revealed that there is widespread use of ethnoveterinary medicinal plants and associated indigenous knowledge in controlling and prevention of livestock diseases in Ethiopia.
The analysis of our data also showed that Solanaceae, Asteraceae, Euphorbiaceae, and Lamiaceae accounted for the largest share of the reported ethnoveterinary medicinal plant families. Solanaceae with 4 species, Asteraceae, Euphorbiaceae, and Lamiaceae with three species each. Similar investigations conducted in Ethiopia (Lulekal et al., 2014; Tekle, 2015; Birhan et al., 2017) and elsewhere (Njoroge & Bussmann, 2006) documented the dominance of these families in the traditional medicines used to treat livestock diseases. This indicated the wider distribution and abundance of these plant families in east Africa. Furthermore, the widespread use of species from these families could be linked to their more effective treatments against diseases (Gazzaneo et al., 2005).
Many of the documented plants in Ensaro district were shrubs (53.7%) that could be linked to an abundance of shrubby plant species in the study area. Similar ethnobotanical studies reported the most abundant use of shrubs in ethnoveterinary medicines (Giday & Teklehaymanot, 2013; Lulekal et al., 2014; Alebie & Mehamed, 2016). Other researchers (Yineger et al., 2008; Eshetu et al., 2015; Birhan et al., 2017; Wodegebriel et al., 2018) found that herbaceous species dominated ethnoveterinary medicine preparations in different regions of Ethiopia. This difference in the use of different life forms of ethnoveterinary plants revealed the existence of different agroecology and indigenous knowledge in various parts of Ethiopia.
Similar to other ethnobotanical inventories conducted in different regions of the country (Lulekal et al., 2014; Birhan et al., 2017), the majority of ethnoveterinary medicinal plants (87.8%) in the present study were collected from wild habitats. In Ethiopia, it is popular to use wild or uncultivated medicinal plants to treat livestock and human diseases (Giday & Teklehaymanot, 2013; Megersa et al., 2013). This implies that the domestication of medicinal plants is not yet the tradition of the users in the country. This may lead to overexploitation and threatening of these plants as there are no conservation actions.
According to our findings, leaves (51%) were the most commonly used plant parts in the study district for the preparation of remedies for the treatment of livestock diseases. In line with the current study, other studies in Ethiopia found that leaves were the most frequently used plant part to treat livestock diseases (Lulekal et al., 2014; Feyera et al., 2017; Kebede et al., 2017).
To make effective and efficient treatments, the majority of ethnoveterinary practitioners in the study district used fresh plant materials (79%). The use of fresh plant materials for remedy preparations is well documented elsewhere in Ethiopia (Lulekal et al., 2014; Eshetu et al., 2015; Maryo et al., 2015; Wodegebriel et al., 2018) as fresh plant materials maintain the majority of bioactive compounds when compared to dry plant materials as they lose volatile but important secondary metabolites.
The majority of informants confirmed that the bulk of preparations (60%) were made by crushing and mixing with water, which is consistent with prior findings from other studies (Eshetu et al., 2015; Kidane et al., 2018). Most informants reported that the main means of administering medicine was oral treatment which agrees with the findings of (Giday et al., 2009; Maryo et al., 2015).
The calculation of fidelity level of medicinal plants found out that Cynodon dactylon, Inula confertiflora, Nicotiana tabacum, Verbascum sinaticum, and Cucumis ficifolius had high fidelity levels. according to Trotter and Logan (1986), fidelity level is a measure of the healing ability of medicinal plants. Therefore, medicinal plants having a high-fidelity level indicates that they are speculated to be effective in their curing potential and can be a good candidate for modern drug formulation.
In addition, the calculation of informant consensus factor values showed that prevalent diseases in the study area have higher informant consensus factor values and less prevalent diseases showed smaller informant consensus values. In addition, the lower values of informant consensus factors indicated that the willingness of sharing indigenous knowledge among traditional healers is minimum. Probably this is due to the belief that their healing activity cannot work if the secret is revealed to others in the study district. Furthermore, traditional healers living in different habitats may use different medicinal plant species to treat the same diseases. The informant consensus values also suggested that people in the community share knowledge about the most significant medicinal plant species for treating the most common ailments.
The preference ranking exercise helped in determining which medicinal plant species are most used to treat blackleg that is frequently reported in the study area. As the result, salvia nilotica, Allium sativum, Cucumis ficifolius, Verbascum sinaticum, and Ruta chalpensis had the highest scores and were identified as the most effective treatments for this disease. Future research on the bioactive components of these medicinal plant species against blackleg also may lead to a good result for the development of drugs.
The results of a direct matrix ranking exercise revealed that the highest values (ranks) for several multipurpose ethnoveterinary medicinal plants in the study area such as Juniperus procera, Millettia ferruginea, Croton macrostachyus, Acacia etbaica, Buddleja polystachya, and Carissa spinarum. This result suggested that these plants are overexploited for non-medicinal purposes rather than for their reported medicinal values. Overharvesting of multipurpose medicinal plants for agricultural land expansion, fuelwood collection, cutting for furniture production, fence, house construction, and charcoal production, and other purposes was identified as contributing factors to the depletion of such species in the study area. As the result, the findings require immediate conservation actions to protect the rapidly declining multipurpose ethnoveterinary medicinal plant species of the study area. The same results showing the highest exploitation of multipurpose ethnoveterinary medicinal plants have been documented from different regions of Ethiopia (Yineger et al., 2007).