1. Introduction

Population growth and economic development have precipitated a surge in demand for high-quality animal protein, consequently escalating the global need for fodder and feed resources in animal husbandry (Speedy, 2002). This burgeoning demand is particularly pronounced in China, catalyzing a structural transformation in the nation's food security paradigm, shifting from a focus on staple food security to feed grain security (Jing et al., 2022). Projections indicate that China's aggregate requirement for fodder and feed stands at 120 million tons, with a current deficit of 50 million tons (Liu et al., 2023). The essence of resolving China's feed shortage and catering to the surging demand for animal protein hinges on rapidly boosting feed production or closing the gap through diversified strategies.

To enhance the overall yield of forage crops, several approaches can be employed. These include expanding the cultivation area for forage crops, increasing the yield per unit area, protecting and improving natural grasslands, fully utilizing by-products and/or residuals of agricultural and forestry production, and making full use of natural biomass. Utilizing crop residues not only aids in managing these agricultural and sideline products but also reduces the environmental burden they cause, such as the emission of air pollutants from the open burning of straw (Xing et al., 2022). Regardless of the approach taken, it is essential to fully understand the diversity and characteristics of forage resources. This understanding allows for the optimization of forage resource allocation and acquisition channels tailored to diverse ecological contexts, stages of development, and established patterns of production and lifestyle. This ensures rational production planning and coordination with staple crop production goals, thereby avoiding conflicts, especially in densely populated areas with limited arable land resources. Moreover, diverse forage resources serve as carriers of genetic diversity, providing a reservoir for breeding crops with superior traits and offering multiple alternatives for combating climate change and environmental risks (Indu et al., 2023). Additionally, diverse forage implies more balanced nutrition and potential medicinal value, significantly influencing the health of livestock and the quality of protein products. Therefore, it is imperative not only to develop high-yield, bulk, and intensive forage crops but also to focus on wild plant resources that adapt to various environmental conditions and are widely recognized and utilized in traditional practices.

Traditional knowledge regarding fodder species embodies the collective wisdom accrued through generations, carefully nurtured by indigenous communities via their profound engagement with local plant resources in animal husbandry. These insights have been naturally assessed through numerous real "animal trials" by observing the animals' foraging behaviors and subsequent health outcomes. Furthermore, it has been subject to a rigorous selection process, taking into account the natural distribution, abundance, adaptability, and resilience of species to diverse environmental conditions. Species that are held in high esteem by local populations serve as a reliable indicator of their overall quality as fodder, rendering this information invaluable to the field of crop breeding science (Geng et al., 2020; Harun et al., 2022). A comprehensive understanding of the diversity of existing fodder resources within communities and the associated local knowledge will significantly contribute to advancing this process. However, there is a paucity of literature documenting the diversity of fodder species and the traditional knowledge pertaining to their utilization by local communities worldwide. Research in this field began in the early 1980s and has since been conducted in various countries, including China, Pakistan, India, Benin, Brazil, West Africa, Serbia, Argentina, Morocco, Ethiopia and Philippines, among others (Samant et al., 2007; Linstädter et al., 2013; Bahru et al., 2014; Nunes et al., 2015; Harun et al., 2017; Naah, 2018; Ouachinou et al., 2018; Salvaña et al., 2019; Molnár et al., 2021; Quiroga and Trillo, 2022; Xie et al., 2023). Livestock health is a primary concern for farmers. Accordingly, studies have documented the traditional knowledge of farmers in East Tyrol (Austria) regarding the use of plants to maintain and enhance animal health and welfare, approaching the subject from the perspective of sustaining livestock well-being (Vogl et al., 2016). Similar research has emphasized the efficacy of plant-based traditional veterinary medicine, which may contribute to new drug development for treating animal ailments (Güler et al., 2021). Research conducted in China includes studies on wild fodder plants utilized by herdsmen in the Gansu–Ningxia–Inner Mongolia junction zone (Xie et al., 2023), by the Dulong people for raising mithun (Bos frontalis), by the Pumi people to feed black-boned sheep in Yunnan Province (Geng et al., 2017; Fan et al., 2022), by the Han people in Zhuxi County of Hubei Province (Yang et al., 2021) and by the Baiku Yao people in Guangxi Province (Hu et al., 2023) to feed pigs, as well as by Tibetans to feed yak (Wang et al., 2024).

China's vast expanse encompasses a diverse topography, with its agricultural production historically demarcated by the 400 mm precipitation line (Liu, 2020). This boundary, stretching from the Greater Khingan Range through Zhangjiakou, Lanzhou, Lhasa, and the eastern Himalayas, delineates a stark contrast in land utilization. The northwestern area, less affected by monsoons, forms a semi-arid region more suited to pastoral pursuits. Conversely, the southeastern region, influenced by monsoons, constitutes a semi-humid zone conducive to agricultural development and human habitation. In these traditional farming regions located southeast of the line, especially those in the southern areas characterized by mountainous terrain, large domesticated animals such as cattle and horses were primarily raised for their draft power, supporting agricultural production. This has shaped the distinctive features of the livestock farming model and structure, defined by small-scale and large groups in southern China (Cao et al., 2020). As society progressed and production tools became mechanized, the role of animal power gradually diminished, while meat production gained prominence. However, due to high population density and limited arable land per capita, the large-scale development of meat-producing livestock remains constrained (Cao et al., 2020). Nevertheless, meat-producing animals, particularly cattle, sheep, and pigs, continue to play a vital role in sustaining livelihoods within these traditional agricultural regions. In most cases, maintaining a modest number of livestock is relatively manageable, offering a high input-output ratio in terms of space, time, and labor resources. Fodder resources, including crop residues and natural biomass from field margins and hillsides, are particularly advantageous. In the majority of rural households in remote mountainous areas, livestock serve two distinct purposes. Firstly, they represent a primary source of animal protein. Secondly, they function as a form of 'mobile banking', with mature animals representing capital and young ones as interest. In addition, livestock provides a means to address urgent financial needs when necessary. The complex and diverse terrain and climatic conditions of China's traditional agricultural regions have endowed them with abundant plant resources, providing a varied array of fodder for livestock rearing. Cumulatively, the known forage plants in China exceed 6704 species (Nan et al., 2022). The traditional knowledge pertaining to these fodder plants remains to be further excavated and systematically compiled.

Zhaotong City, in Yunnan Province, boasts a long history of animal husbandry, featuring livestock breeds such as Zhaotong Yellow Cattle, Wujin Pigs, Yunnan Fine-Wool Sheep, Weixin White Goats, and Yanjin Black-Bone Chickens (Rong, 2013). However, the preservation of these breeds faces challenges from large-scale farming and frozen semen improvement technologies. For instance, the number of Zhaotong Yellow Cattle has significantly decreased, with only about 12, 000 remaining, constituting just 4.1% of the population in 2010 (Huang et al., 2023). Despite this, local residents have accumulated rich knowledge on fodder resources, breeding experience and techniques, forming livestock farming models adapted to the local environment, representing a quintessential example of the traditional integrated farming system in southern China. Furthermore, Zhaotong is a multi-ethnic region, where the diverse breeding practices and cultural traditions of different ethnic groups bring diversity and innovation to livestock farming. In recent years, aligned with the rural revitalization strategies, the local government has aimed to develop a distinctive cattle farming model and brand of eco-friendly, high-quality products. A scientific analysis of the ecological, economic, and cultural factors behind the cattle farming model is fundamental to achieving this goal.

This study explores and documents the diversity of fodder resources and associated traditional knowledge within the integrated farming and pastoral systems of Zhaotong City, an exemplar of southern China's mountainous regions. By emphasizing local forage resources for cattle husbandry, this study delivers systematic and scientific information to enhance the sustainability of high-quality beef cattle farming, support rural revitalization, and provide a model for other similar regions worldwide.

2. Materials and methods 2.1. Study area

Zhaotong City is situated in the northeastern region of Yunnan Province, China (102°52′–105°19′E, 26°55′–28°36′N), sharing its borders with Guizhou Province to the east and Sichuan Province to the northwest. Spanning an area of 23, 021 km², the city is predominantly characterized by mountainous terrain, with 96.6% of its area being mountainous (Liang et al., 2012). The topography of Zhaotong is marked by an elevation gradient that increases towards the southwest and decreases towards the northeast, creating a northward sloping landscape typical of plateau mountainous regions. The city's lowest elevation is recorded at Gunkanba (267 m a.s.l.) in Shuifu County, while the highest elevation is at Yaoshan (4041.6 m a.s.l.) in Qiaojia County. Due to its varied topography and significant elevational differences, Zhaotong City experiences a plateau monsoon climate system (Cheng and Yang, 2018), with hot-dry climate in the valley and cold-humid climate at top of the mountain. The average annual temperature in the central city ranges from 11.7 ℃ to 20.9 ℃, with an average annual rainfall of 880.8 mm.

The topographical and climatic characteristics of Zhaotong City have created conditions for traditional semi-agro-semi-pastoral lifestyles. Zhaotong boasts rich grassland resources and has been one of the regions in Yunnan Province where grass cultivation practices have been implemented (Li, 2021). According to the third national land survey data report of Zhaotong City, the total arable land area is 457, 224.50 hm², and the grassland area is 115, 041.84 hm² (ZMPG, 2019). The area of natural pasture is 21, 017.39 hm², the area of artificial pasture is 4929.98 hm², and the area of other grasslands is 89, 094.47 hm² (ZMPG, 2019). The distinctive geographical features and abundant grassland resources of the region make it particularly suitable for the development of small-scale family-based beef cattle farming, where the majority of herds consist of fewer than ten cattle. This farming model smartly leverages the advantages of the rural landscape and agricultural resources, effectively utilizing the surplus of rural labor force (Ruan, 2018), agriculture by-products and wild resources; it also takes advantage of cattle forces for agricultural activity. Thus, cattle are important assets for mountain farmers of Zhaotong City, who master the key knowledge of the diversity, nutrition and utilization of the fodder plants. These farmers generally feed the cattle with cultivated grass, crop residues, and indigenous fodder species.

Based on government data, Zhaotong City possessed a total of 496, 215 cattle in 2022 (Table 1), accounting for 5.65% of cattle in Yunnan Province, which is representative of cattle husbandry in the region. Our survey was conducted in Zhaoyang District, Qiaojia County, and Zhenxiong County, which have a relatively large number of beef cattle farms that best represent cattle husbandry in Zhaotong City. Following recommendations from the local government, our ethnobotanical research was conducted in 19 villages in 7 townships, across three counties that have relatively large number of beef cattle (Fig. 1). Elevations in the study area range from 1189 to 3105 m (Table 2).

2.2. Ethnobotanical survey and data collection

Ethnobotanical field surveys were conducted in June-August 2021 and July-August 2023. Snowball sampling and a random sampling method were used to select informants and each of the interviews was carried out via home visit and field visit. Semi-structured interviews were employed, using questionnaires that included the following types of questions: 1) demographic information such as age, gender, ethnic group, and educational background; 2) lists of fodder plants for beef cattle; 3) ethnobotanical knowledge and practices of fodder plants such as local name of fodder plants, source (wild or cultivated), part(s) consumed, preparation method(s), harvesting times, and utilization season. All interviews were conducted in Yunnan dialects and recorded in portable notebooks. Fodder plants mentioned by locals were documented photographically. Prior ethical approval was obtained from the local government in the selected research areas. During the interviews, we obtained prior consent from informants, and we adhered to the international code of ethics of the International Society of Ethnobiology (ISE, 2006).

2.3. Collection and identification of specimens

After interviews, specimens were collected from the field with the help of the key informants to verify plant species involved. All materials were labeled with numbers and local names, and photographs of all specimens were taken. The specimens were identified with support from taxonomic experts by referencing the Flora of China (https://www.iplant.cn/), the taxonomic circumscription of plant families and species followed the APG Ⅳ system (Byng et al., 2016), while Plants of the World Online (https://powo.science.kew.org/; POWO, 2024) and The World Flora Online (https://www.worldfloraonline.org; WFO, 2024) were employed to verify accepted Latin names. All specimens were deposited in the herbarium of the Kunming Institute of Botany (KUN), CAS.

2.4. Demographic information of the informants

A total of 140 informants were interviewed, all of whom were engaged in beef cattle farming. They comprised 105 males and 35 females. The greater proportion of male informants may reflect the fact that males predominantly oversee herding activities. Additionally, local gender roles, with men typically responsible for external family communications and women for internal affairs, may have influenced the gender distribution of informants. The age of the informants ranged from 22 to 81 years, with an average of 53.81 years. Using the World Health Organization (https://www.who.int/) age classification criteria, informants were categorized into three groups: young (18–44 years), middle-aged (45–59 years), and elderly (60 years and above). The age distribution of beef cattle farmers across the three regions was predominantly middle-aged (44–59 years old), indicating this age group is currently the primary force in rural beef cattle breeding, and suggesting an aging trend in the industry. The overall level of education among the informants is relatively low, with half having received basic primary education (50.00%), and a significant number having no formal education (42.14%). Only four informants received an education at the high school level or above (Table 3).

2.5. Data analysis

All recorded data were tabulated in Microsoft Excel (2016). The elevation distribution of fodder plants was analyzed using the geom_violin function in the ggplot2 package in R 4.4.0 (Ginestet, 2011), with citation number of the fodder plant named by the informants at given elevation range. Relative frequency of citation (RFC) (Tardio and Pardo-de-Santayana, 2008) was used to rank the citation frequency of fodder plants, which indicates their relative importance. Specifically, a higher RFC value indicates a higher frequency of utilization for the plant. RFC was calculated as follows:

Where FC is the number of informants that mentioned the use of the species as fodder, and N is the total number of informants included in the study. We used RFC values to rank the most cited fodder plants.

3. Results 3.1. Diversity of fodder plants, parts consumed, life forms, and methods of preparation

In total, 125 plant taxa (including 3 varieties and 5 subspecies) were reported, including 106 wild and 19 cultivated fodder plants (Appendix A), belonging to 35 families and 111 genera. The top ten families most frequently mentioned by informants were Poaceae (27 taxa, 21.43%), Asteraceae (17 taxa, 13.49%), Fabaceae (14 taxa, 11.11%), Polygonaceae (9 taxa, 7.14%), Lamiaceae (4 taxa, 3.17%), Ranunculaceae (4 taxa, 3.17%), Rosaceae (4 taxa, 3.17%), Plantaginaceae (3 taxa, 2.38%), Moraceae (3 taxa, 2.38%) and Amaranthaceae (3 taxa, 2.38%) (Fig. 2a). Taxa of those 10 families represented 69.84% (88 taxa) of all fodder plants cited.

The greatest category of plant part consumed was the whole plant, with 80 taxa (64.00% of the total), followed by aerial parts, with 23 taxa (18.40%), tender leaves, with 6 taxa (4.80%), tender leaves and branches, with 10 taxa (8.00%), straw, with 5 taxa (4.00%), and tuber, with 1 taxon (0.80%) (Fig. 2b). Most documented fodder plants in this study are herbs (106 taxa, 84.80%), followed by shrubs (8 taxa, 6.40%), woody vines (5 taxa, 4.00%), herbaceous vines (3 taxa, 2.40%) and trees (3 taxa, 2.40%) (Fig. 2c).

In the study area, fodder plants are prepared raw for cattle, except for the roots of Lophiolepis mairei (H. Lév.) Bureš, Del Guacchio, Iamonico & P. Caputo and the tubers of Solanum tuberosum, which need to be cooked. Most fodder plants were fed fresh to cattle (114 taxa, 91.20%), while 5 (4.00%) fodder plants were reported to be fed to cattle both fresh and dry, and 6 (4.80%) fodder plants were dry fed (Fig. 2d).

3.2. Prioritization of fodder plants

A total of 1488 URs of 125 plant taxa were recorded. In this study, the RFC values range from 0.01 to 0.76, with 27 taxa having RFC values higher than 0.08 (the average RFC value). We consider these important local fodder species. The ten most commonly cited fodder plants include 5 wild and 5 cultivated species. The 5 cultivated forage grasses are Zea mays L. (RFC = 0.76, URs = 106), Brassica rapa L. (RFC = 0.63, URs = 88), Solanum tuberosum (RFC = 0.48, URs = 67), Lolium perenne L. (RFC = 0.39, URs = 66) and Dactylis glomerata L. (RFC = 0.33, URs = 46). The five wild forage grasses are Eragrostis nigra Nees ex Steud. (RFC = 0.47, URs = 66), Artemisia dubia Wall. ex Besser (RFC = 0.47, URs = 66), Digitaria sanguinalis (L.) Scop. (RFC = 0.43, URs = 60), Cenchrus flaccidus (Griseb.) Morrone (RFC = 0.41, URs = 58) and Chenopodium ficifolium Sm. (RFC = 0.26, URs = 37).

3.3. Elevational distribution of fodder plants

In total, 27 wild fodder taxa were utilized by farmers in low-elevation areas (< 1500 m a.s.l.), 67 taxa were plant reported in mid-elevation areas (1500–2500 m a.s.l.), and 66 taxa were used in high-elevation areas (> 2500 m a.s.l.) (Table 4). The top 20 cited wild fodder plants are mostly distributed in mid-elevation areas, whereas the commonly used species in low-elevation areas are Digitaria sanguinalis, Setaria faberi R.A.W. Herrm., Echinochloa crus-galli (L.) P. Beauv, etc. In high-altitude areas, the commonly cited species are Eragrostis nigra, Taraxacum sinicum Kitag., Lophiolepis mairei, Plantago asiatica subsp. erosa (Wall.) Z.Yu Li, Argentina lineata (Trevir.) Soják (Fig. 3). We found that in this region Z . mays and S. tuberosum are the main taxa locally cultivated, with a broad range suitable from low to high elevations. Lolium perenne, Dactylis glomerata, Brassica rapa, Pennisetum sinese Roxb, Raphanus raphanistrum subsp. sativus (L.) Domin, Vicia cracca L., Fagopyrum esculentum Moench, Avena sativa L., Secale cereale L. and Trifolium repens L., are cultivated in high-elevation areas. In the low-to-mid elevation areas, Lolium multiflorum Lam., R. raphanistrum subsp. sativus, and P. sinese are commonly cultivated.

3.4. Seasonal feeding regime and their sources

Based on the timing of feeding, the utilization of fodder plants can be seasonally divided into summer-autumn and winter-spring periods, each with a distinct combination of fresh grass and dry hay. Summer and autumn represent the peak periods of fodder growth, providing an abundance of fodder plant resources. The wild forage is particularly significant during this period, occupying equivalent proportions to that of cultivated fodder. In total, 106 taxa are utilized in summer-autumn, 12 in winter-spring, and seven taxa are used throughout the year. During the summer and autumn, all fodder is used fresh; in winter, eight taxa are used fresh, while the remainder serve as dry fodder. At times these fodder plants are mixed with corn flour, bran, chaff, etc., to improve palatability and increase nutritional value (Table 5).

4. Discussion 4.1. Beneficial effects of rich and diversified fodder plants

In Zhaotong City, we documented a diverse array of fodder plants, encompassing 125 plant taxa, with wild species constituting the majority. Similar findings have been observed in other studies, with species richness ranging from 142 to 348 (Geng et al., 2017; Scarpa, 2024). Here we discuss three effects of rich and diversified fodder plants on local livestock farming.

4.1.1. Prolonging the duration of forage provisions and minimizing the supply discrepancy tailored to various elevation ranges

One of the foremost challenges in rearing ruminant livestock lies in the uneven temporal and spatial distribution of forage resources. During the growing season, fodder is abundant; however, it becomes scarce in the non-growing season, with variations across different elevational ranges. Diversifying forage sources emerges as a pivotal strategy for local farmers to address this uneven distribution. This approach can extend the fodder supply period to a certain degree and mitigate supply gaps across various elevation zones. The cultivation of diverse plant species, thriving in different seasons at varying elevations, can ensure a consistent year-round supply of fodder, thereby alleviating the issue of seasonal forage deficits. This is paramount for maintaining livestock health and ultimate productivity. Research conducted in Australia has revealed that a diversified forage base can sustain 1.4 to 3 times the stocking rate compared to a single forage source (Bell et al., 2018). Our investigation identified 106 species harvested in summer and 12 species in winter, while an additional seven species can be harvested throughout the year. Consequently, farmers tend to provide more fresh wild fodder species to cattle during the summer-autumn season, while preserving cultivated fodder crops in desiccated form. More significantly, cold-tolerant crops including Brassica rapa, Raphanus raphanistrum subsp. sativus, and Lolium multiflorum are cultivated for winter utilization. In Zhaotong and other mountainous regions, farmers also confront the challenge of inadequate arable land, with conflicts arising in land allocation between forage and staple crop cultivation. To optimize supply, reliance on a substantial number of wild fodder resources from non-arable land becomes imperative. Our study identified 27 wild fodder species utilized by farmers at elevations below 1500 m, while a greater diversity of species was observed in higher elevation regions, with 67 species found between 1500 and 2500 m and 66 species above 2500 m. This pattern reflects a heightened dependence on wild fodder resources at higher elevations, where arable land with favorable conditions is less readily available.

4.1.2. Reducing risks and improving adaptations to climate change

Diversifying sources of forage is a crucial risk management strategy in livestock farming. Diversifying forage sources can enhance the resilience of livestock farming, stabilize productivity, and increase the ability to adapt to climate change. Different fodder species have unique growth cycles and environmental requirements; thus, while one species might suffer due to drought, another might thrive. This diversification not only ensures a continuous supply of feed for livestock but also helps to maintain soil health and biodiversity. By using multiple fodder sources, farmers can reduce the risk of total crop failure and promote a more sustainable and resilient livestock farming system that can adapt more effectively to changing climate conditions.

4.1.3. Improving animal health and meat nutrition through nutritional diversity

Different plants provide varied ingredients, and a diverse range of plant species can offer more comprehensive nutrition and secondary metabolites, meeting the various nutritional and health needs of livestock. For example, some plants such as Trifolium repens, Chenopodium ficifolium, and Vicia cracca are rich in protein, whereas others are rich in fiber, such as Z ea mays, Eragrostis nigra, and Setaria faberi, among others. A diverse diet of forage helps livestock obtain balanced nutrition, and some plants can provide functions for preventing and treating animal diseases, thereby improving their health and production performance. Research indicates that ruminant feeding systems based on diverse forages can result in more desirable concentrations of fatty acids (FA) and antioxidants in meat, ultimately affecting meat quality (Kearns et al., 2023). This leads to an increase in the content of vitamin E and carotenoids in muscle, enhancing the meat's antioxidant potential, thus improving lipid and color stability (Kearns et al., 2023). In Zhaotong City, farmers generally believe that livestock consuming forage from diverse sources are healthier. A study by Vogl et al. (2016) in Austria found similar results. Many local wild fodder possesses medicinal value, and when beef cattle graze or farmers collect wild fodder, these medicinal plants are ingested along with the regular fodder. This practice not only provides rich nutrition for the cattle but also enhances their immunity, thereby helping to prevent diseases to a certain extent. This natural approach to disease prevention will become increasingly essential in the future of livestock farming, as many countries have restricted or banned the use of antibiotics in animal feed. In 2006, the European Union prohibited the use of antibiotics in feed, followed by the United States in 2014, which banned defensive antibiotics, and South Korea in 2018 (Wang et al., 2021). The Ministry of Agriculture and Rural Affairs of the People's Republic of China also issued Notice No. 194, withdrawing all growth-promoting feed additives except traditional Chinese medicine starting January 1, 2020 (MARA, 2019). With the implementation of the "ban on antibiotics" policy, the demand for antibiotic alternatives and green feed is expected to increase significantly in the future. This is especially true for forages that inhibit gastrointestinal pathogenic infections, enhance immunity, and are environmentally friendly.

4.2. The preference of fodder resources

The preferential use of certain species and families as fodder for ruminants is deeply rooted in their ability to fulfill the key characteristics that define superior forage. These plants not only support the unique digestive mechanisms of ruminants but also provide a comprehensive nutritional profile that is essential for their health and productivity, including high nutritional value, good fiber characteristics, high small intestine digestibility, palatability, safety, cost-effectiveness, processing and storage stability, etc. In Zhaotong City, the Poaceae, Asteraceae, Polygonaceae, Fabaceae, and Lamiaceae families were highly preferred at the family level, while Z ea mays (RFC = 0.76), B rassica rapa (RFC = 0.63), Solanum tuberosum (RFC = 0.48), Eragrostis nigra (RFC = 0.47), A rtemisia dubia (RFC = 0.47) were highly preferred at the species level.

4.2.1. Preferred families

The Poaceae family, stands out as a primary source of forage globally due to its high fiber and energy content, which is fundamental for rumen function and the production of volatile fatty acids. The fibrous structure of grasses promotes the rumen's fermentation process, offering a continuous energy supply for ruminants (Van Soest, 1994). In addition to their value as excellent fiber, they are also beneficial for treating infectious diseases and digestive system disorders, as revealed by a study in Punjab, Pakistan on the use of Poaceae in animals, which found 149 species of Poaceae plants with traditional ethno-veterinary applications (Majeed et al., 2020).

Legumes from the Fabaceae family are highly esteemed for their significant protein content and their ability to fix nitrogen, which enriches soil fertility. These plants provide a balanced array of essential amino acids, contributing significantly to the muscle development and milk production of ruminants (NRC, 2001). Nevertheless, despite the general importance of Fabaceae species as a protein source, farmers in Zhaotong City handle Fabaceae fodder plants with caution and regulate their consumption. According to the farmers, Fabaceae plants are rich in protein and highly nutritious, but excessive consumption by cattle can cause bloating, particularly in calves, and may even lead to death. For example, Vicia cracca is highly nutritious and is typically sun-dried before being used as feed. Local people avoid feeding fresh or semi-dried V. cracca to cattle, as it can easily cause bloating and negatively affect livestock health.

While the Asteraceae family may not match the protein levels of legumes, their adaptability across various growing conditions and their nutritional contributions makes them a valuable component of the ruminant diet. The Polygonaceae family, including species like buckwheat, is recognized for its high mineral content, offering a rich source of micronutrients vital for ruminant health and metabolic functions. Other plant families, such as the Brassicaceae, contribute unique nutritional elements; for example, plants from the cabbage family are noted for their high protein and sulfur content, which are beneficial for ruminant nutrition and overall health (McDonald et al., 2019).

4.2.2. Preferred wild fodder species

Wild fodder plants are important sources of fodder in summer and autumn, accounting for 50% of the total fodder in Zhaotong City. Local farmers consider Eragrostis nigra an excellent fodder plant with high feeding value. It is a perennial grass. The stems and leaves are soft and tender with high palatability. It can be used both in grazing and green mowing. Previous research on E. nigra has characterized its protein levels (9.14%), modest quantities of lipids (1.47%), ample carbohydrates (8.22% of total digestible nutrients), significant fiber content (29.89% crude fiber), a rich array of minerals (such as 0.85% calcium, 0.20% phosphorus, and 1.23% potassium) and notable digestibility rate (70%), suggesting that it is an excellent fodder with comprehensive and balanced nutritional profile for ruminants (Pant and Dhami, 2003). In addition, this species exhibits drought tolerance, rendering it an ideal candidate for use as both an economically viable and environmentally friendly fodder and grassland restoration option (Zhao et al., 2017). However, as a wild fodder plant, the seed is not commercially available, which limits its large-scale application. In our study sites, local farmers collect seeds by themselves. Research on the seed yield and germination characteristics of wild Eragrostis spp. in Yunnan (Zhao et al., 2017) has shown that the average seed yield of E. nigra is 154.26 kg/ha, with a maximum yield of 187.5 kg/ha and a minimum yield of 96.4 kg/ha. The thousand-grain weight of E. nigra is generally light and is below 0.1 g, indicating that fine land preparation should be conducted during sowing, and the soil coverage be kept as shallow as possible to ensure the successful emergence of seeds. As a prospective fodder resource, E. nigra requires further investigation and breeding efforts to enhance its utilization value as fodder, thus contributing to the sustainable development of Yunnan's grassland husbandry.

Local farmers do not consider A rtemisia dubia to be palatable or nutritious. The reason for its high RFC was mainly attributed to its importance during the time of fodder scarcity. It is an abundant resource easily accessible in the area, commonly found along roadsides, fields, and mountain slopes. When fresh grass is scarce, cattle consume the tender leaves of A. dubia but avoid it when alternatives are available. Farmers often collect A. dubia, chop and mix it with other fodder to achieve a satiating effect. A. dubia has been shown to have a high crude protein (13.56%), ether extract (4.62%), significant crude ash (8.22%), a notable fiber content (29.54% crude fiber), rich in minerals (such as 1.71% calcium, 0.06% phosphorus), and nitrogen free extract (38.10%), making it a good fodder (Wu et al., 2007). However, A. dubia has a strong smell during the green stage, which reduces its palatability to cattle, leading to reduced intake. The palatability varies among different livestock; for example, it is a preferred fodder for rabbits, with good palatability and a consumption rate of 72.2% (Xue et al., 2012). It promotes stomach health, and acts as an antidiarrheal and antibacterial. Feeding it during the plum rain season can prevent rabbit diarrhea and gastrointestinal diseases (Chen et al., 1994). It is important during periods of fodder scarcity, and in the future, further research should be done on its utilization methods to improve its palatability and fully realize its resource value.

Digitaria sanguinalis is also considered a good fodder plant by local people. Interestingly, it is regarded as a weed for other crops, particularity in corn production systems. Nevertheless, research in the United States has demonstrated that when intercropped with corn, it does not compete for resources and maintains high corn yields (La Guardia Nave and Corbin, 2018). Research on the nutritional value of this species has indicated that it has moderate fodder properties (Nuwanyakpa et al., 1983). However, more recent research that compared D. sanguinalis with other four warm-season grasses found that although it is popular among producers, its high cost and relatively low profitability prompt a recommendation for producers to consider alternative warm-season grasses as substitutes for grazing beef cattle (Boyer et al., 2020). Water-use efficiency analysis showed this species could be a potential fodder species that maintains relatively high productivity even under arid conditions (Gelley et al., 2020). Taken together these findings indicate that the quality and economic benefit of using D. sanguinalis as fodder remains controversial. Further research is required to verify the practical value of this species. Moreover, caution and measures should be taken into consideration for the proper control of the negative impact of this species to other crops and ecosystem.

Cenchrus flaccidus is a commendable perennial grass, characterized by both fodder and ecological attributes, demonstrating robust adaptability to various environments. It exhibits rapid growth, high productivity, excellent palatability, and significant nutritional value (Zhang et al., 2022). This species is recognized as a stable and high-quality fodder, possessing notable resistance to drought and low temperatures. Its cultivation is straightforward, requiring minimal technical expertise and extensive management practices, making it an ideal candidate for the establishment of artificial grasslands, particularly in the challenging alpine environment. Currently, it is cultivated in the Xizang region, and the area of cultivation of C. flaccidus in alpine areas is still expanding (Xiao et al., 2024). As a nitrogen-loving plant, C. flaccidus thrives with fertilization, further augmenting its yield (Xiao et al., 2024). Native to the middle and upper reaches of the Yarlung Zangbo River, C. flaccidus was proposed for the restoration of degraded grasslands and the creation of artificial grasslands in Tibet (Zhang et al., 2022). However, farmers in Zhaotong have yet to cultivate this fodder. In the future, research on its cultivation should be intensified to offer a new possibility for the development of fodder in the Zhaotong mountain animal husbandry region.

Farmers in Zhaotong also collect Chenopodium ficifolium as a supplement enjoyed by cattle. C. ficifolium is an annual herbaceous plant in the Amaranthaceae family, commonly found as a weed in wheat fields. It has a long growth period, long grazing utilization time, with tender stems and leaves, good palatability, rich in nutrients, high crude protein content (28.13%) and ether extract content (2.66%), and low fiber content (11.21%), making it a medium fodder (Chen and Jia, 2002). However, C. ficifolium is an excellent wild feed plant for pigs (Yang et al., 2021). It is worth noting that according to local farmers, overconsumption of Chenopodium spp. may cause swelling of the cattle's tongue, but the specific component causing this has not been reported. As a commonly used feed, further study is required to determine the effects and safety of this fodder.

4.3. Fodder cultivation with plateau characteristics

In the high-elevation regions of Zhaotong, farmers cultivate various fodder crops such as Dactylis glomerata, Lolium perenne, Secale cereale, Avena sativa, and B rassica rapa. Common combinations include mixed plantings of D. glomerata, L. perenne, Trifolium repens, and T. pratense, which are grass species promoted by the government. These mixed planting pastures are noted for their high yield and stability, with the complementary effects of nutrient absorption through ecological niche separation among different species, which enhances the productivity and stability of the community. S. cereale, an important food crop and fodder for cold regions worldwide, was introduced to northeastern Yunnan Province in the mid-1960s (Xiao et al., 1991). It is characterized by high yield, good quality, and wide adaptability, making it a valuable feed crop. Through long-term cultivation and selection, it has become an excellent dry-season feed crop for alpine areas. Currently, in northeastern Yunnan, S. cereale is mainly used for one-time mowing and sun-drying of hay during the maturation period.

Vicia cracca is another important crop used for both food and fodder, known for its high fodder yield, good palatability, and rich nutrition. It effectively addresses the issue of livestock "winter thinness, spring fatigue." Avena sativa prefers cool temperatures and is tolerant of poor soil, salt-alkali conditions, drought, and cold, making it highly favored by farmers in high-elevation areas. It plays an irreplaceable role in sustaining the development of animal husbandry.

Brassica rapa, with a long history of use in medicine, food, and fodder, is rich in nutrients, including carbohydrates, proteins, fats, minerals, vitamins, and carotenoids, making it a high-quality feed (Wang, 2018). Feeding freshly chopped B. rapa to lactating cows has been shown to increase milk production (Vogl et al., 2016).

4.4. Rich traditional knowledge on veterinary medicine

Local farmers possess a wealth of traditional veterinary knowledge, employing wild fodder plants to address common ailments such as indigestion, diarrhea, and inflammation in their livestock. Among the plants mentioned, Argentina lineata was noted for its efficacy in treating indigestion, dysentery, diarrhea, and non-rumination in beef cattle. Traditional use of A. lineata to treat these conditions includes boiling the roots of the plant and administering the resulting decoction to the cattle. Studies have found that it has an antibacterial effect, and is commonly used for stomach pain, dysentery, carbuncles, hematochezia, dyspepsia, and other digestive disorders (Li, 2022). Given the critical role of a healthy digestive system in ruminant animals like beef cattle, any disruption to normal rumination due to conditions such as rumen bloat, indigestion, gastrointestinal infections, inflammation, or ulcers can significantly impact their development and even lead to mortality (Du et al., 2024). Despite the potential benefits, there has been no research to date on the use of A. lineata as a feed additive. Future studies could investigate its potential as a valuable component in animal feed.

Taraxacum sinicum is a versatile species with medicinal, edible, and fodder values. This plant is abundant in Zhaotong and is frequently cited by locals, who believe that feeding it to beef cattle enhances immunity and reduces illness, with many farmers noting its anti-inflammatory properties. Taraxacum spp. are known to have bactericidal effects on hemolytic streptococcus and exhibit significant anti-inflammatory properties (Park et al., 2011). They are also popular as wild vegetables and can be processed into beverages, pastries, candies, and other health foods. Additionally, research has shown that they can serve as a compound feed additive, promoting postpartum lactation in sows and aiding healthy growth in piglets (Liu, 2013).

Cattle diarrhea is a prevalent gastrointestinal disease that significantly impacts cattle by causing malnutrition and growth disorders. In this study, local farmers frequently cite several plants effective in treating diarrhea in beef cattle, including Plantago spp. (e.g., P. asiatica subsp. erosa, P. major, P. lanceolata L.), Bistorta vivipara (L.) Delarbre, and Persicaria lapathifolia (L.) Delarbre. The whole plant parts of the Plantago spp. are used for cattle diarrhea, whereas B. vivipara and P. lapathifolia are typically valued for their roots. The preparation methods are straightforward: the plants are usually boiled in water and the decoction given to the cattle. Many plants of genus Plantago are used globally. As is well-known to Chinese medicine, adding plantain powder to cattle feed can treat gastrointestinal diseases, thanks to therapeutic effects of various active components (Wei et al., 2024). In Turkey, Plantago spp. are also used to treat human skin diseases (Karaköse, 2022) and the intestinal and wound healing of livestock (Güler et al., 2021). B. vivipara is a traditional folk medicine. Medicinal traders from Zhaotong frequently purchase its rhizomes, which are collected and sold by local farmers. P. lapathifolia, is another common folk medicinal plant. Its fruits and stems have antioxidative, antibacterial, anti-inflammatory, and antipyretic effects (Li et al., 2009). It also can be applied externally to treat insect bites in humans or taken internally to relieve pain, ulcers, diarrhea, dysentery, eczema, and malnutrition.

According to farmers, Bidens pilosa is valued for its heat-clearing and detoxifying properties. It is widely used in the livestock industry, often fed as green fodder to livestock. Its proper inclusion in feed can improve the daily weight gain of pigs (Xie et al., 2015). Additionally, it is a commonly used veterinary medicine. Research indicates that B. pilosa can reduce the dystocia rate in pigs, treat hypertension, enhance intestinal function, and has a notable antipyretic effect on rabbits with fever (Zhang et al., 2017). Its application prospects in the livestock industry are promising, as it can serve as excellent fodder, traditional Chinese medicine for treating livestock diseases, and a feed additive to boost production (Ren et al., 2021).

4.5. Prospects on scientific interpretation and wider application of indigenous knowledge of fodder plants 4.5.1. Providing scientific basis for natural grass-fed Zhaotong Yellow Cattle

Having observed the energy-intensive and extensive cattle farming practices predominantly employed by developed nations, there is now a global shift towards reintegrating crop-livestock systems (Sulc and Franzluebbers, 2014; Pédèches et al., 2023). This reversal is driven by the pursuit of synergistic ecological and economic advantages, enhanced resilience in the face of climate change, and increased adaptability to market fluctuations. Within this evolving paradigm, multispecies forage production systems are being actively promoted and implemented. In response to the burgeoning demand for bio-natural and eco-friendly products, a substantial disparity exists between the prices of grass-fed and grain-fed meat products, with the former commanding a significantly higher price. This provides an opportunity for regions such as Zhaotong City, where traditional crop-livestock practices still prevail. In accordance with governmental policy initiatives to fortify the branding of naturally grazed Zhaotong Yellow Cattle, it is imperative to establish a comprehensive scientific foundation for cattle feed practices. This encompasses thorough research into fodder nutritional assessment, digestibility, meat quality, and alternatives to antibiotics. Detailed nutritional evaluations of indigenous fodder plants will reveal their particular advantages and optimize feed formulations. Studies on digestibility will inform feeding strategies that maximize nutrient uptake and growth efficiency. Furthermore, research into the effect of various fodder plants on meat quality will ensure the brand underscores superior taste and nutritional value. Exploring natural antibiotic alternatives, by leveraging the medicinal properties of plants such as Plantago spp. and B idens pilosa, will promote sustainable and health-conscious livestock management practices. By integrating indigenous knowledge with scientific research, the productivity, health, and marketability of Zhaotong Yellow Cattle can be significantly enhanced, thus contributing to the region's economic and ecological resilience.

4.5.2. Collecting, evaluating, and preserving forage germplasm resources

A central element in the advancement of applied indigenous knowledge in fodder plants is the systematic collection, assessment, and conservation of forage germplasm resources. Australia's creation of the Australian Pastures Genebank (APG), which houses approximately 85, 000 accessions, stands as a paragon. This contemporary, global diversity resource for plant scientists has become essential to numerous Australian grazing systems, aiding plant breeders in enhancing species' adaptability to previously marginal climates, soils, and systems (Smith et al., 2021). Establishing a similar germplasm and/or gene bank for Zhaotong City or for a wider area would enable researchers to safeguard invaluable genetic resources and support the development of fodder crops with heightened resilience to future climatic conditions. This genetic diversity can be harnessed to develop novel crop varieties, ensuring the sustainability of the livestock sector amidst evolving environmental contexts. Harnessing the genetic diversity of fodder crops and their wild relatives will be pivotal in developing varieties better suited to future climatic scenarios, thereby ensuring the sustainable progression of the livestock sector (Indu et al., 2023).

5. Conclusion

We documented 125 plant taxa (including 3 varieties and 5 subspecies) belonging to 35 families and 111 genera used as fodder, and characterized traditional knowledge on the utilization of this fodder in a mountainous city in southern China, which represents an integrated farm-livestock system. The diverse species used reflect local wisdom in addressing shortages caused by uneven spatial-temporal distribution of fodder species. This serves as a comprehensive strategy to mitigate unpredictable environmental and climate risks, balance nutrition, and offer preventive and therapeutic measures for animal diseases. Wild fodder species, being particularly important, deserve more attention as they are reservoirs of genetic resources for breeding high-quality fodder crops and for adapting to future climatic changes. Species such as Eragrostis nigra, A rtemisia dubia, Digitaria sanguinalis, and Cenchrus flaccidus should be further evaluated for their nutritional value, digestibility, and impacts on meat quality. Some species (e.g., Argentina lineata, Taraxacum sinicum, Bistorta vivipara, B idens pilosa and Plantago asiatica subsp. erosa) should be investigated for their medicinal properties and potential use as alternatives to antibiotics. To systematically promote research on fodder species, we recommend establishing a germplasm bank or gene bank. The results from the present study demonstrate that by exploring the rich but less studied treasure trove of fodder plants and their traditional knowledge, we can provide essential insights and information that may support sustainable development of integrated farm-livestock systems and foster innovation to address the mounting pressures from population growth, environmental degradation, and climate change.

Acknowledgements

This study was supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDA26050301-02). Firstly, we are grateful to all informants in Qiaojia County, Zhaoyang District, and Zhenxiong County of Zhaotong City for their contributions and for sharing their knowledge, as well as their participation and guidance in specimen collection when needed. Secondly, special thanks to Director Banggao Wu from Chongxi Town People's Government, Mr. Daxin Yang from Kunming Branch of the Chinese Academy of Sciences, Mayor Chao Liu and Secretary Chaowei Yue and Director Youping Ruan from Heishu Town People's Government, Minister Long Chen and Deputy Secretary Gaofeng He from Muxiang Town People's Government for their support and permission during the field surveys. Furthermore, we also would like to express our appreciation to the local guides who accompanied us during the field surveys. Last but not the least, we also thank Mingfu Liu for the participation in the field surveys, and all members of the research group for their support.

CRediT authorship contribution statement

Xian Chen: Writing – original draft, Investigation, Formal analysis, Data curation. Pyae Phyo Hein: Writing – review & editing. Mengxue Shi: Investigation. Fen Yang: Investigation. Jun Yang: Resources. Yao Fu: Visualization, Conceptualization. Xuefei Yang: Writing – review & editing, Visualization, Supervision, Conceptualization.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Xuefei Yang is an Editor for Plant Diversity and was not involved in the editorial review or the decision to publish this article.

Appendix A. Supplementary data

Supplementary data to this article can be found online at https://doi.org/10.1016/j.pld.2024.09.011.