The traditional feed of Luchuan pigs

A total of 51 feed plants were reported by the respondents, belonging to 21 families and 43 genera (Table 1). Among these feed plants, the Asteraceae, Poaceae, and Amaranthaceae families were the most represented, with 11, 6, and 5 species, respectively. Various parts of the plants were utilized as feed, including above-ground parts, whole plants, leaves, fruits, seeds, seed coats, rice husks, stems, and root blocks, with above-ground parts and whole plants being the primary components, accounting for 37.7% and 22.6%, respectively. More than half of the feed plants used for Luchuan pigs were wild plants (accounting for 56.6% of the total) (some images are shown in Fig. 2), while cultivated plants accounted for 41.5%. The results showed that the comprehensive utilization scores of Luchuan pig feed plants ranged from 10 to 24 points. Rice (Oryza sativa), corn (Zea mays), Pennisetum purpureum, sweet potato (Ipomoea batatas), wheat (Triticum aestivum subsp. spelta), and soybean obtained (Glycine max) relatively high scores, indicating their significant comprehensive utilization value in Luchuan pig farming. Apart from wheat, which needs to be introduced, all these plants are commonly cultivated locally. P. purpureum, on the other hand, is both harvested from the wild and cultivated by some individuals.

Table 1 The inventory of feed plants for Luchuan pigsFig. 2

Part of wild feed plants for Luchuan Pigs. (a Celosia argentea, b Pennisetum purpureum, c Commelina diffusa, d Polygonum plebeium, e Persicaria lapathifolia, f Portulaca oleracea, g Stellaria aquatica, h Pontederia crassipes, i Erechtites valerianifolius, all photographs were taken by Yongqing Liufu.)

This study shows that Luchuan pig feed plants are mainly herbaceous plants (accounting for 92.2%). This result is similar to other ethnobotanical cases in Europe and other regions of Guangxi [30, 32]. The wild herbaceous plants we recorded are mainly weeds, among which Pennisetum purpureum, Colocasia esculenta, Commelina diffusa, Pontederia crassipes, Solanum americanum, Emilia sonchifolia, Portulaca oleracea are the most favorite forage plants harvested by local Hakka people. On the one hand, these plants are commonly found in the wastelands and ditches near their homes, which provide a convenient source of feed during periods of feed shortage. On the other hand, for local Hakka people, these plants are well-known and have multiple uses: S. americanum, E. sonchifolia, and P. oleracea are commonly used as wild vegetables and medicinal plants. P. crassipes is a commonly used weaving plant by Hakka people. P. purpureum and C. diffusa serve as fodder plants for local cattle and other livestock. The leafstalk of C. esculenta is utilized by locals to make pickled food, while its root is a commonly used starchy edible plant.

Among the 51 feed plants, the farmers classified rice, corn, soybean, peanut bran, and wheat, which have relatively high nutritional content, as concentrate feed. The remaining 46 feed plants, including P. purpureum, sweet potato (I. batatas), and taro (C. esculenta), were categorized as roughage. Different species of concentrate and roughage supplements are provided to Luchuan pigs during different growth stages. During the gestation period, it is essential to balance the nutritional needs of pregnant sows. For piglets aged 0 to 2 months, their protein requirements are high, and they primarily rely on maternal milk supplemented with appropriate solid food. They should be fed 4 to 5 times a day with a diet consisting mainly of porridge, corn (Z. mays) flour, soybean (G. max) meal, and wheat (T. aestivum subsp. spelta) bran, mixed with small amounts of fish meal and bone meal. After reaching a weight of 7.5 kg, roughage feed should be gradually introduced. Piglets can be kept in confinement after weaning or gradually switched to free-range feeding. When confined, they should be fed twice a day, with roughage as the main component and a small amount of concentrate feed. During free-range feeding, they can be fed once in the morning or evening, with the rest of the time spent foraging on wild plants.

The favorable weather and unique geographical environment have nurtured abundant feed plant resources in Luchuan. The survey results reveal that a large variety of plants are available year-round to feed Luchuan pigs. Among the feed plants used for Luchuan pigs, 23 species can be harvested throughout the year, accounting for 45.10% of the total; 16 species are harvested in spring (31.37%), 14 species in summer (27.45%), 13 species in autumn (24.49%), and 10 species in winter (19.61%). During late winter and early spring, farmers mainly compensate for the insufficient feed by strengthening the cultivation of melons, fruits, and vegetables. Some farmers also utilize fermentation techniques to preserve plant feed, such as fermenting P. purpureum. They rarely use artificial feed, as they believe that feeding artificial feed may lead to issues such as fever, constipation, and digestive problems in Luchuan pigs.

During our participatory survey of free-range pigs, we found that Luchuan pigs consume a greater variety of wild plants than that the respondents reported, such as Eleusine indica, Ludwigia adscendens, Erigeron canadensis. The respondents who raised free-range pigs mentioned that they were familiar with certain plants but did not know their specific names. However, when we interviewed the handlers of captive-bred Luchuan pigs, they were able to name the commonly used feed plants and their other functions. A study from Nigeria also found that farmers who kept confined animals had a greater knowledge about the resources compared with farmers who raised animals free in the pasture [33].

Compared to the present, in the past, farmers used more wild plants to feed Luchuan pigs, especially during times of grain scarcity when people had no choice but to rely on wild plants. However, with improvements in living standards and changes in feeding practices, many traditional wild-feed plants have been replaced by fermented feed and cultivated plants. Similar to other Chinese local pig breeds [29], the traditional knowledge about the utilization and management of wild-feed plants is facing significant risks of extinction in the local community.

The traditional veterinary medicine for Luchuan pigs

Traditional herbal medicine is an important source of medication used by farmers to treat ailments in Luchuan pigs. The results of this study show that a total of 62 species of herbal medicines were reported by the respondents for treating diseases in Luchuan pigs (Table 2, Fig. 3). Common diseases in Luchuan pigs include cold, cough, wheezing, constipation, anorexia, indigestion, internal heat, and diarrhea.

Table 2 The inventory of veterinary plant for Luchuan PigsFig. 3

Part of veterinary plants for Luchuan Pigs. (a Ricinus communis, b Cymbopogon citratus, c Mussaenda pubescens, d Emilia sonchifolia, e Prunus persica, f Averrhoa carambola, g Mangifera indica, h Solanum americanum, i Baeckea frutescens, all photographs were taken by Yongqing Liufu.)

Pig farmers mentioned that feeding Luchuan pigs with rice (O. sativa) bran, soybean (G. max) meal, and peanut (Arachis hypogaea) bran can easily lead to internal heat and associated issues such as anorexia, constipation, and wheezing. Therefore, they place great emphasis on preventing internal heat in the process of pig farming. They use 27 species of crushed or grinded herbs decocted and mixed into the feed as a preventive and treatment measure for internal heat in Luchuan pigs. Locally, these herbal concoctions are referred to as “cooling teas”. Additionally, they adjust the daily diet of Luchuan pigs to prevent and treat internal heat. For instance, when symptoms of internal heat occur in Luchuan pigs, the feeders reduce the proportion of rice (O. sativa) bran, soybean (G. max) meal, and peanut (Arachis hypogaea) bran in their food while increasing the proportion of wheat (T. aestivum subsp. spelta) bran, sweet potato (I. batatas) shoots, and Musa acuminata. These plants promote gastrointestinal motility in pigs, thereby alleviating symptoms such as constipation and indigestion.

According to the interviewees, newborn piglets and pigs raised under forested conditions are prone to skin diseases. To address this, the local people use 14 species of plants, such as Pinus massoniana, Melia azedarach, Eucalyptus robusta, Tripterygium wilfordii, and Cymbopogon citratus, for pig bathing. They believe that these plants have excellent therapeutic effects and can treat and prevent approximately 95% of skin diseases. Research results indicate that active ingredients in plants like E. robusta, and T. wilfordii have vermifugal, insecticidal, and antibacterial effects [34,35,36]. In traditional Chinese medicine, T. wilfordiiis also used for treating autoimmune diseases like rheumatoid arthritis, glomerulonephritis, and systemic lupus erythematosus [36]. During the survey, it was observed that farmers prefer placing C. citratus, Prunus persica leaves, and Lygodium japonicum directly inside the pigsty for pigs to sleep on. According to their accounts, this practice effectively repels mosquitoes, parasites and prevents skin diseases in piglets. C. citratus emits a strong aroma and is reported to have effective chemical components with antibacterial and insect-repelling properties [37,38,39].

It is worth noting that among the medicinal plants we have documented, three of them have been reported to posse toxicity. For example, M. azedarach has been reported that the bark of M. azedarach has cytotoxic effects and may result in gastrointestinal, cardiovascular, respiratory, or neurological effects, and death in severe cases [40, 41]. Also, the commonly used industrial plant Ricinus communis is also used locally; it contains highly toxic compounds such as Ricinus communis agglutinin and the alkaloid ricinine [42]. Besides, Tripterygium wilfordii has toxicity and adverse reactions, especially the hepatotoxicity [43]. These plants are mainly used by local people to relieve itching, repel insects, and treat other skin diseases in Luchuan pigs. The toxic herbal species can be potentially lethal, but their effects are closely tied to their processing methods, usage, and dosage [41, 44]. In the context of animal health, knowledge of various toxic and poisonous species is a prerequisite for safe grazing as grazing on such species could be fatal resulting in economic loss [45, 46]. Therefore, the utilization and scientific validation of these related plants should also draw the attention of local residents, local governments, and researchers.

In the past, the treatment of Luchuan pigs’ illnesses mainly relied on herbal medicine. With the development of modern medical technology, modern farmers now primarily depend on vaccines and Western medicine to treat pig diseases. Indeed, animal vaccination has significantly contributed to the prevention and control of severe animal diseases. However, this shift toward modern medical practices may have adversely affected the traditional knowledge system concerning livestock health and welfare, as vaccines have become readily available for most farmers, and disease prevention is now the primary focus [1]. Nonetheless, in treating less severe health issues and in more isolated regions, traditional ethnic veterinary practices may still serve as an essential low-cost alternative to “Western” veterinary methods [1]. Therefore, effective measures should be taken to promote the use of traditional herbal remedies. For instance, utilizing pig farming association platforms to disseminate common knowledge about traditional Chinese veterinary medicine among farmers.

Luchuan pig farming models

In our investigation, we observed a historic transformation in the Luchuan pig farming industry, achieved through collaborative efforts among the government, enterprises, and farmers, transitioning from traditional confinement systems to more environmentally friendly and sustainable practices: ecological farming and free-range in the forest (Fig. 4).

Fig. 4

The ecological farming and free-range farming of Luchuan Pigs. (a free-range farming on mountain areas (by Song Li), b free-range farming in fruit ranch (by Guixin Chen), c the ecological farming base (by Jinming Li), d Luchuan Pigs on slatted floors (by Song Li))

In the ecological farming model, farms are typically established within artificial economic and fruit forests, accompanied by fish ponds. The pig pens are equipped with innovative features such as slatted floors, automated feeding and watering systems, and centralized manure treatment pools. The use of automated equipment significantly reduces feed and labor costs. Moreover, the slatted floors in the pig pens enhance ventilation, reducing the risks of harmful gases for the pigs and lowering the likelihood of diseases among Luchuan pigs. To mitigate environmental pollution from pig feces and urine, farmers primarily employ techniques such as solid–liquid separation and biogas fermentation to treat the excrement in an eco-friendly manner. The processed pig manure serves as a natural fertilizer for fruit trees, forest plants, and pasture within the farm, while the biogas slurry is used to raise fish or irrigate crops. This “pig farming + fish farming” and “pig farming + cultivation” ecological farming model not only minimizes environmental pollution from waste but also promotes sustainability and generates additional economic income for the farmers.

In the free-range in the forest model, Luchuan pig farmers divide the mountainous area into several sections and practice low-density rotational grazing to allow for free-range feeding. This method helps reduce the potential threats to the ecological environment caused by overgrazing. To manage Luchuan pigs more efficiently during the night and provide shelter during adverse weather conditions (such as rain or high temperatures), farmers often build simple houses on the mountain. Luchuan pigs in the forest are familiar with their owner’s voice or whistle and can return to designated areas based on specific signals. Under this model, Luchuan pigs are only fed once a day, which reduces feed costs. Due to the minimal input required and low economic risks, free-range pig farming is gaining popularity and plays a significant role in the livelihoods of many rural families worldwide [47,48,49].

In the wild, pigs are active during the day and spend 75% of their active time on foraging activities [50]. Their increased activity contributes to better health and improved meat quality compared to typical domestic pigs [3, 30, 51, 52]. Research indicates that free-range pigs living in vast, comfortable natural environments have enhanced immunity and disease resistance [3].

Breeding utilization and industrial development of Luchuan pigs

Luchuan pigs may have limited market share due to their small size, slow growth, and low lean meat percentage. However, they possess valuable genetic traits such as high prolificacy, tolerance to coarse feed, high reproductive capacity, early maturation, and easy fattening, making them of significant genetic breeding value. For instance, crossbreeding Luchuan sows with Danish Landrace boars produces hybrid offspring, and further crossing these hybrids with Duroc boars creates three-way crossbred pigs. Likewise, crossbreeding Luchuan sows with Duroc boars yields black pig offspring, and crossing these offspring with Danish Landrace boars results in three-way crossbred pigs (Fig. 5). The hybrid pigs exhibit excellent adaptability, high productivity, and superior meat quality, giving them a competitive edge in the market [53].

Fig. 5

The breeding application of Luchuan Pigs. (a Luchuan pig (by Song Li), b Duroc boar (by Shichong Wang), c Hybrid black pig (by Yongqing Liufu), d Danish Landrace boars (By Shichong Wang), e Hybrid black-spotted white pig (by Yongqing Liufu))

In southern China, Luchuan pig is recognized as an ideal hybrid female parent. In the past, Hakka people primarily raised Luchuan pigs to meet their family's protein needs. Currently, due to increasing recognition of the genetic breeding value of Luchuan pigs, many farmers are rearing them with the intention of acquiring more female pigs and subsequently attaining greater economic benefits through hybrid breeding. This practice not only satisfies people's demand for traditional diets but also successfully achieves economic benefits. This farming practice objectively promotes the protection of Luchuan pigs and has a positive significance for safeguarding both the biological and cultural diversity of Luchuan County. Therefore, in the future, while conducting rescue and protection work for traditional knowledge, there should be a focused effort on preserving the genetic resources of local varieties.

The Luchuan pig farming industry is a distinctive sector in Luchuan County. According to statistics, in 2016, the total output value of Luchuan pigs reached 5-billion-yuan, accounting for 70% of the counties' total agricultural output [54]. In recent years, the government has undertaken significant efforts to protect and breed Luchuan pigs. These efforts include establishing a national-level Luchuan pig conservation center, setting up Luchuan pig protection areas in five different towns, providing financial subsidies to Luchuan pig breeders, and promoting the Luchuan pig brand, etc.

Despite these measures, the production and utilization of Luchuan pigs still face several challenges. Firstly, the current sales market for Luchuan pigs mainly relies on local consumption. However, with the impact of low-cost, high-yield pork from Europe and America, it is difficult for Luchuan pigs to fetch competitive prices in the market. Secondly, due to insufficient consumer awareness of Luchuan pigs, fraudulent practices in the pork market led to a significant negative impact on the sales of genuine Luchuan pork. Although the government is working toward building the Luchuan pig brand, there are currently only few Luchuan pig specialty chain stores in Yulin, Guigang, and Nanning in Guangxi, which is insufficient for promoting and disseminating Luchuan pigs. Additionally, epidemics have always posed the most significant obstacle to pig farming [55]. In 2018, African swine fever was introduced into China, resulting in an outbreak. According to disease prevention policies, all deceased pigs, culled pigs, their products, potentially contaminated feed, equipment, and waste materials were subject to safe disposal. Similar to other pigbreed in China [3], during the outbreak of African swine fever, Luchuan pigs suffered significant losses, with the number decreasing from over 1.31 million to 235,000, causing substantial economic damage to breeders [54]. While some interviewees mentioned the effectiveness of strict epidemic prevention measures and feeding “liangcha” (cooling herbal tea) to pigs to reduce the occurrence and spread of African swine fever, most pig breeders lack experience in epidemic prevention and control, leading them to avoid pig farming risks.

Therefore, to promote and protect Luchuan pigs, government agencies, related companies and non-governmental organizations need to take proactive measures, such as (1) increasing the promotion of breeding and farming methods; (2) utilizing the pig farming association platform to educate farmers on preventing and treating common diseases; (3) enhancing research and development in pork processing to expand Luchuan pig meat products in domestic and international markets; (4) conducting effective publicity through museums, promotional events, media, etc., to increase consumer awareness of Luchuan pigs; and (5) attracting investment to establish more specialty chain stores.

Folk culture and customs related to Luchuan pigs

Luchuan pigs play a significant role in the local Hakka traditional dietary culture, social rituals, festive celebrations, and customary practices (Fig. 6). Among the Hakka community, Luchuan pigs are regarded as symbols of kindness, good fortune, and blessings. The locals adhere to feeding Luchuan pigs with natural feeds. Luchuan pig meat is highly valued for its delicious taste and nutritional benefits, making it a precious ingredient in both culinary and medicinal practices. Additionally, in the Hakka culture of worship and offerings, pigs are considered the most sincere and meaningful tribute to the deities.

Fig. 6

Luchuan Pig Cultural Festival and Luchuan Pig cuisine. (a Luchuan Pig cuisine cooking competition (by Yongqing Liufu), b Luchuan Pig cuisine (by Weicui Wu ))

Dietary culture

The traditional practice of feeding Luchuan pigs with natural feed is closely related to the lifestyle habits of the Luchuan Hakka people. In the past, the Luchuan Hakka people relished “Lao Fan”, which was a dish made by boiling a large quantity of water with rice in a wok, then scooping out the cooked rice with a ladle. They would mix the leftover rice broth with other plant fodders to feed pigs. Until now, many farmers in rural areas still maintain this traditional method of feed production.

Luchuan pigs belong to the fatty-type breed, characterized by tender, aromatic, crisp, and sweet meat. Locals prepare various pork dishes to entertain guests, creating a rich culture centered around consuming pork. Commonly enjoyed dishes include white-cut pig’s feet, roasted suckling pig, braised pork, cured pork, sausage, and preserved meat. For the Hakka community in Luchuan, the Luchuan pig serves not only as a source of nutritional food but also as an important medicinal resource for preventing and treating illnesses.

Through long-term practical experience, they have developed the concept of “Doctrine of Signature”, using specific parts of the pig to address corresponding health issues. Such as consuming pig's blood to replenish blood, pig's kidneys to nourish the kidneys, and pig's feet to strengthen the feet. Local Hakka people use pig liver, and goji (Lycium chinense) leaves together to make soup with the effects of liver clearing and vision improvement. Stewed pig's ears with Combretum alfredii are used to treat tinnitus, while a soup made from Tinospora sinensis and pig's feet is employed to alleviate rheumatic bone pain and other ailments.

Folk festivals and traditional customs

The Luchuan pigs play a significant role in the local Hakka traditional customs. Locally, when a Hakka man gets married, it is customary to present a pig's head and tail to the matchmaker as a gesture of gratitude. Additionally, the Luchuan pig is an essential offering in the worship of deities and ancestors during traditional festivals and important customs among the Hakka people. Particularly during the Qingming Festival and the Double Ninth Festival, affluent Hakka families often use a roasted suckling pig as an offering to their ancestors (Fig. 6b). The Hakka people of Luchuan believe that pigs are easy to raise and bring good fortune. Therefore, if a child is weak and prone to illness, their parents may offer a Luchuan pig or a pig's head to the local earth god, praying for the child to be as healthy and fortunate as a pig.

Amid urbanization and changing lifestyles, many traditional ceremonies are gradually fading from people's view. However, the cultural significance related to pigs remains well-preserved in the Hakka region of Luchuan County. The Luchuan pig not only holds an important place in Hakka culture but also serves as a medium for reflecting the distinct characteristics of the local Hakka people. The Hakka people of Luchuan are known for their kindness, warmth, hospitality, gratitude, and reverence for deities and ancestors. They share the best pork with guests to express hospitality and gratitude and offer pork as the finest tribute to deities and ancestors, conveying their reverence and fond remembrance. These cultural values likely serve as a vital driving force in preserving the local traditional customs and culture. Therefore, while safeguarding the genetic resources of the Luchuan pig, equal emphasis should be placed on the conservation of the associated traditional customs and of Hakka culture.

Luchuan pig cultural festival

In recent years, local governments have frequently organized cultural festivals related to the Luchuan pig industry to promote its development. During these cultural festivals, various artists and food enthusiasts utilize the pig as a medium to showcase and celebrate the local Hakka culture, which includes Hakka opera, Hakka folk songs, and Hakka cuisine, among other elements. They employ various forms of expression such as calligraphy, photography, theatrical performances, and culinary demonstrations to promote the Luchuan pig.

Simultaneously, domestic and international pig farming experts, entrepreneurs, and government officials are invited to participate in these cultural festivals. They share and exchange experiences related to Luchuan pig breeding, management, product processing, sales, promotion, and conservation. The rich heritage of Hakka traditional customs and culture infuses cultural elements into the promotion and preservation of the Luchuan pig, further propelling the development of the Luchuan pig industry.