Potential and risk of traditional African and Asian veterinary phytotherapy for the reduction of the use of antibiotics in European production animals

The use of infeed antibiotics was an important way to promote animal growth and to enhance feed efficiency. But non-therapeutic antimicrobial uses are also linked to the development of multidrug resistance (MDR) in bacteria, including resistance against drugs needed for human health care [1]. Sweden was in 1986 the first to prohibit the use of some of the antibiotics in animal feeds [2], and the European Union (EU) banned all antibiotic growth promoters since 2006 [3]. In Asia and Africa however, its use is still prevalent.

But reducing antibiotics in Europe gave rise to an increase in infections and reduced animal production. So, feed companies and research institutes looked for alternatives. For the reduction of the use of antibiotics herbal feed additives are available which help animals to cope with stress, support gut flora and the immune system. Immune modulation by plant constituents can be as a result of direct activation of innate defense mechanisms acting on receptors and inducing intracellular gene(s) expression that result in the production of antimicrobial molecules [4].

Herbal feed additives from Africa are scarce. But ethnoveterinary medicine is readily available in Africa. Ethnoveterinary medicine is defined as the combination of knowledge, skills, and practices based on the experiences, theories and beliefs in indigenous cultures that are used for healing animals. According to African beliefs diseases may also be related to supernatural causes such as angered or evil spirits and witchcraft [5]. Risks for animal herbal remedies will be similar as those encountered with human herbal remedies, consisting of poor quality control and safety. Some examples are the presence of pyrrolizidine alkaloids (PA’s) and heavy metals. Investigation for PA’s in 70 well known herbal commercial remedies in Ghana showed that 60% of the analyzed herbal products contained PA’s (average 25.0 μg/kg). The maximum PA level (1290.0 μg/kg) was found in a regulatory-approved herbal medicine not known to contain PA-plant parts [6].

Asian feed additives are better developed due to the huge market for pig, cattle and poultry products. Alternatives for antibiotics in animal production including plant-extracts are extensively described [4]. Recently China has vowed to stop adding routine antibiotics to animal feed, starting in 2020, to reduce the ill effects of overuse, and some Chinese livestock companies are exploring the potential of traditional Chinese medicine to promote healthy development of animals [7]. The Kangfa Animal Drug Institute in Changchun does research with TCM additives for poultry and pigs and claims that these herbs can reduce stress, inflammatory response and mortality, and increase feed intake, feed conversion and weight gain [7].

In this presentation a short overview is given on the developments in Asia and Africa and some promising plants, such as e. g., Peperomia pellucida ([Abb. 1]) which is used in skin disorders in all animal species especially for the treatment of fungal and bacterial infections, are evaluated.

Peperomia pellucida (L.) Kunth. Quelle: Prenn, CC-BY-SA-3.0

 

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• Literatur

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• 3 Council Regulation EC No. 1831/2003 https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32003R1831&from=EN
• 4 Cheng G. et al. Antibiotic alternatives: the substitution of antibiotics in animal husbandry?. Frontiers in Microbiol 2014; 5: 217
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• 7 Zhiming X, Liu M, Han J. TCM herbs may replace antibiotics to improve animal health China Daily 2019-12–31.

Publication History

Article published online:
13 June 2022