Global consumption of animal products continues to increase sharply along with the growth of the population. In livestock farming, antibiotics are usually used for growth promotion or better feed efficiency, thus leading to the prolonged dose exposure of animal gut bacteria to these drugs. However, the treatment of antibiotics to animals is approved by FDA only for: (1) diseased animals, (2) disease control, and (3) disease prevention. The antibiotic-resistant bacteria could potentially infect people via routes such as raw/undercooked meat, vegetables/fruits contaminated by livestock wasted waters, or personal contacts without suitable hygiene. Meanwhile, due to the increasing consumers’ concern on food quality and safety, the trend of an antibiotics-free feeding model of livestock is requested. The innovation of animal vaccines and health-promotion of feed additives for livestock animals becomes an important challenge of the industry. Health-promotion of feed additives include probiotics, phytogenics, fungi, micro-nutrients, and peptides, etc. The two-day symposium held in Taiwan invited local and foreign scientists and experts to share their research achievements regarding animal vaccines and health-promotion feed additives. Through this seminar, the utilization of animal vaccines and health-promotion feed additives in the livestock industry elevated the industry to a healthier level. Also, the technology exchanges stimulated the vigorous development of animal vaccines and health-promotion feed additive industries in the Asia-Pacific region. The export competitiveness of Taiwan’s animal vaccine and feed additive industries have also been promoted.
Three session topics related to the animal vaccines and feed additives were highlighted respectively in the workshop sessions:
The workshop concept was initially proposed by TLRI and organized by FFTC in partnership with TLRI, COA, AHRI, ATRI, TIER, and APAARI using the Webex Event (max. 1,000 participants) and Facebook live streaming.
Twenty experts from six countries ((Indonesia, Japan, Malaysia, Philippines, Taiwan, and the U.S.A.), shared their experiences to increase the awareness and application of animal vaccines and health-promotion feed additives in the livestock industry. The presentation materials include 20 PPTs, 13 papers, and 20 videos.
Key takeaways were summarized by presentation:
Keynote 1 Due to the use of many antimicrobials in animals, many ARB (Antibiotic-Resistant Bacteria) have been detected in animals. Therefore, countermeasures to reduce the use of antimicrobials in animals and develop alternative strategies such as vaccines, probiotic cytokines, enzymes, immunomodulators, immunostimulants, and bacteriophages are required. In addition, to restrict the use of antibiotics in the livestock and poultry industries, the positive efficacy of current probiotics to improve productivity and growth, counter various diseases, and increase feed efficiency could be expected to accelerate the adoption will of probiotics and efficiently reduce the emergency risk of ARB. (Dr. Masaru Usui, Japan)
Keynote 2 With increasing regulatory restrictions and consumer concerns regarding the use of antibiotic growth promoters (AGP), there is a need to develop alternative-to-antibiotics (ATAs) in animal production systems to meet the food demands for an ever-increasing human population. Various antibiotic alternative strategies which enable the sustainability of animal productivity and allow poultry to perform to their genetic potential under existing commercial conditions were introduced. Using optimal combinations of various alternatives coupled with good management and husbandry practices holds the key to maximizing performance and maintaining animal productivity while we move forward with the ultimate goal of reducing antibiotic use in the animal industry. (Dr. Hyun Lillehoj, USA)
Keynote 3 The global consumption of livestock products is continuously increasing along with the growth of the human population. Antibiotics are widely used as a growth promoter in the livestock industry in the past. Based on the higher demand for quality and safe livestock products from consumers, there is a strong demand for antibiotic-free feeding models of livestock. Therefore, the innovation of healthcare feed additives for livestock becomes an important issue of the industry. This inter-department project aims to innovate feed additives from probiotics, phytogenic, fungi, micro-element, deodorant, anti-bacteria peptide, and novel metabolic molecular as alternatives to antibiotics for the livestock industry. In addition, the value-added logo application for functional feed additives and regulations and guidelines for Chinese herbal veterinary medicine would need further efforts to make a clear and friendly environment for industry development. (Dr. Churng-Faung Lee, Taiwan)
Keynote 4 The reverse vaccinology technology platform is considered to be the most sophisticated method of antigen discovery, initially used for developing human vaccines. A total of 11 vaccines and diagnostic reagents have been developed in the past three years, among which the technologies of 4 products were transferred successfully with total royalties of over NT$50 million. This cross-field collaboration mode will continue to integrate different emerging cutting-edge technologies, develop innovative animal vaccine products and more efficient technology platforms, enhance the commercialization and internationalization of resulting R&D, and lead the animal vaccine industry towards exciting new horizons. (Dr. Jiunn-Horng Lin, Taiwan)
S1-1 Newcastle disease (ND) is a serious infectious disease of poultry caused by the Newcastle disease virus (NDV). Several methods are normally adopted for farmers to deliver vaccines to chickens, including spray and drinking water in which uniformity of antibody response in farms is of great concern. Based on the collected data of primary immune response and viral distribution among organs, comparisons among spray, drinking water, and eye-drop were conducted to estimate the immune efficacy and viral protection. The eye-drop vaccination is recommended to farmers as the optimal way to primary vaccination for the chickens. (Dr. Happy K. Shieh, Taiwan)
S1-2 The implementation of biosecurity strategies is an indispensable task in modern swine farms. Taking PRRS as an example, proper biosecurity strategies can successfully reduce the PRRS virus concentration and spread it in pig farms. The implementation of biosecurity can cut off the chain of infection, and comprehensively control the hazards of PRRS on swine farms. With the application of vaccination and implementation of ten major measures on swine farm biosecurity, it is shown a successful control of the PRRS spread and increasing post-weaning survival rate to 95%, concluded from a filed study in a 5,000 farrow-to-finish pig farm in Taiwan. (Dr. Shu-Hwae Lee, Taiwan)
S1-3 For industrial pig farming, oral vaccines must be desirable for mass vaccination of pigs due to the relative ease of administration to large populations, however, it is not available in the swine industry. Taking the advantage of recombinant DNA technology combining antigens within a single microorganism and producing a live vaccine simultaneously active against several different diseases, bacterial vectors were utilized as a vaccine vector in this study due to the main characters of genome size tolerance. The constructed recombinant E. rhusiopathiae has been shown to enhance the local and systemic humoral immune responses against bacterial antigens in pigs receiving the recombinant strain via the oral route. In the future, it is expected that the E. rhusiopathiae-based vaccine will be applied to a variety of diseases in pigs and other animal species, including wild boars, which often act as reservoirs for important infectious agents. (Dr. Yoshihiro Shimoji, Japan)
S1-4 Diarrhea, caused by enteropathogenic Escherichia coli, is known as the number four deadly disease in the world and is ranked as the 2nd most disease in Indonesia, which resulted in the death number of 460 babies per day. It is reported one of the antimicrobial peptides (AMP), Plantaricin which is isolated from lactic acid bacteria, could be considered as a tentative antibiotic candidate against both gram-negative and positive bacteria. Based on the Plantaricin treatment, the experiment concluded with a significant immune response (increased number of hemoglobin, hematokrit, and leucocytes) against enteropathogenic Escherichia coli. The derived results supported the role of Plantaricin as an antimicrobial agent and its clinical application in the future. (Dr. Huda S. Darusman, Indonesia)
S1-5 The Philippines is ranked as the 8th pork producer and 16th broiler producer in the world. Currently, the Philippines has limited tools and infrastructure to diagnose, track and prevent disease outbreaks effectively and rapidly, while modern animal disease diagnostic laboratories are in their infancy. The speaker argued that harmonious collaboration between the government, industry stakeholders, academe, and research institutions are critical elements to invigorate the veterinary industry in the Philippines. (Dr. Dennis V. Umali, the Philippines)
S1-6 Newcastle disease (ND) caused by Newcastle disease virus (NDV) is an avian disease affecting birds worldwide, especially important for the poultry farming industry. Animal Health Research Institute (AHRI) has successfully established a reverse genetics platform of NDV and accordingly invented an ND live vaccine with complete novelty and high freedom to operate. In response to a rapid change of emergency diseases and also the market demands of livestock farming, the ND vector platform has also been established for commercialization of ND live vaccine through technical transfer, and extension development into multivalent-vector vaccine platform for other avian vaccine products. (Dr. Ai-Ping Hsu, Taiwan)
S2-1 Phytogenics, composed of a single or a mixture of phytochemicals from medicinal plants, was considered as an alternative strategy against avian coccidiosis. In this presentation, Rotam-CS, a commercial phytogenic formulation of tentative anti-coccidial function, was assessed and evaluated. The experimental result of various assays showed a promising impact of Rotam-CS as a prophylactic and therapeutic remedy to treating protozoal diseases in chickens by interfering coccidiosis life cycle at the stage of sporulation as well as sporozoite entering into gut epithelia. (Dr. Wen-Chin Yang, Taiwan)
S2-2 In recent decades, the “omics” technologies have emerged as powerful tools for better understanding physiological mechanisms in the context of the cell, tissue, or organism. To increase stress susceptibility and alleviate the illness caused by environmental impacts of farm animals, omics technologies can systematically study the complex interactions of actions of feed additives in animals. By using omics approaches in the development of anti-stress feed additives for pigs in this presentation, a novel metabolic molecule identified by comparative metabolomics can be a biomarker as the main active ingredient. It was also mentioned that functional feed additives could be developed to implement other functions, such as anti-stress, modulating the immune response of animals, diarrhea prevention, or balancing gut microorganisms. (Dr. Yu-Chun Lin, Taiwan)
S2-3 To reduce agriculture’s environmental impact, the speaker and his team proposed the concept of recycling food waste as animal feed to be a replacement for conventional animal feed. Cassava pulp (CP), which is starch-rich but nutrient-poor, is generated as a low-value by-product of cassava starch processing. The use of FCP (fermented cassava pulp), a product that is enriched in protein and water-soluble vitamins, as a feed supplement, is demonstrated as a good potential animal food supplement or feedstuff in dairy cows. It is also argued that FCP use could help prevent the misuse of antibiotics while enhancing the health of dairy cattle. (Dr. Yoshinori Murata, Japan)
S2-4 Though Europe has reduced the use of antibiotics in animal feeding, many countries still prefer using antibiotics in swine feeds. Concluding from current studies, antibiotic alternative sources include probiotics, prebiotics, acidifiers, enzymes, herbal extracts, and heavy metals. The speaker argued that despite positive results being found to improve animal growth performance and intestinal health for these alternative materials, the efficacy and effectiveness cannot compare to that of conventional antibiotics in the swine industry. More efforts and studies are needed in the future. (Dr. Gary Chiang, Taiwan)
S2-5 The definition of “Feed” and “Feed Additive” in the Feed Control Act refers to “foodstuffs that provide nutrition to or promote healthy growth of, livestock, poultry, and aquatic animals” and “the non-drug non-nutrient substances proclaimed by the central competent authority to be added into feedstuffs to improve feed efficacy, maintain feed quality, facilitate the growth of livestock, poultry, and aquatic animals, and keep them healthy” respectively. The listed material in each category is officially proclaimed after mandatory testing for possible changes in biosafety or quality level after manufacturing, processing, packing, or importation aiming for quality control. The speaker presents a holistic framework of the classification of feeds and feed additives, feed produced, and the Feed Control Act in Taiwan. (Dr. Pei-Mei Chen, Taiwan)
S2-6 With over 50 years of continuous feed additives used to improve the feed efficiency, growth, and health of animals in the Malaysian livestock industry, an increase in livestock population subsequently increased the demand for better quality feed additives and feeds. To echo growing concern for the safety and quality of meat and meat products from consumers, adoption of non-antibiotics feed additives as a substitute of prevalent antibiotic growth promoters (AGP) is necessary. Malaysia has already implemented a few measures to contain the widespread antibiotic resistance under The Feed Act 2009. Through the Feed Act, the government has the power to control the use of antibiotics in feeds for growth promotion and disease prevention (prophylaxis) on food-producing animals such as the ban on the use of Avoparcin, Chloramphenicol, Nitrofurans, Teicoplanin, Vancomycin, Carbadox, and Olaquindox. (Dr. Noraini Samat, Malaysia)
General discussion This session was moderated by FFTC Director, Dr. Su-San Chang, and all the speakers and moderators, and participants in the Cisco Webex meeting room, were invited to join the discussion and share their thoughts. The discussion points and responses were briefly summarized below:
Point 1. As antibiotics are generally banned to be used as feed additives, what is the role and potential in the extracts from Chinese herbal medicine/plants as an alternative feed additive option? Based on the cross-department joint projects, according to TLRI, the phytogenics is identified as a potential feed additive alternative candidate and demonstrated effects similar to antibiotics in terms of microbial inhibition and digestion capacity improvement. The whole individual of plant/Chinese herbal medicine, including root, stem, and leaves, is experimentally shown to have the antibiotic-similar effect, which strengthens its application potential to replace antibiotics as feed additive alternatives in the future.
Point 2. When using yeast or bacterium as a vector, is there any issue such as safety, be concerned? Humans have a long history of interacting with and using yeast in daily life to satisfy various needs, including food processing and fermentation. For yeast species from the non-convention category, there is still a must need to experiment with safety evaluation.
Point 3. Before being licensed to be legitimate use in general, what kind of evaluation criteria of safety and efficacy should be achieved for probiotics and phytochemicals? The category of feed additive contains many items, such as probiotics, enzymes, amino acids, and peptides, etc. However, there is no standard regulatory framework for the recommended use, more budgets and basic studies are needed to clarify the relationship/safety/efficacy of diverse items belonging to the feed additives.
In addition, it is possible to decrease the number of antibiotics used in poultry/livestock farms through suitable environmental control (temperature, hygiene, etc.) and vaccination. The same concept was also echoed by Dr. Shu-Hwae Lee, presenting the important role of biosecurity strategy in swine farms. In the process of gradual antibiotic reduction, it is also found, based on the field observation, the growth performance of piglets/chickens is negatively affected. As a result, despite the complete removal of antibiotics in the feed being the ultimate goal, the current need is to identify a balance point between antibiotics and environmental control/vaccination before the antibiotic-alternative feed additives are available.
Point 4. Except for vaccination and feed additives, how about using breeding technics to produce disease-resistant/tolerance lines, e.g., against PRRS? According to TLRI, there has been positive news in yellow cows about heat- and disease-tolerance breeding lines and the project is ongoing. The outcome is expected to be optimistic.
Regarding the issue of antibiotic use in the animal industry, compared to human-related topics, the size and scale of the animal industry are relatively small and positively affect resources and budgets. It is critical to obtain more public attention and awareness to strengthen the development and progress in the animal industry.
S3-1 The global livestock industry has made great steps towards antibiotics reduction, also a growing consciousness from consumers for foods that are perceived to be natural, as well as foods from animals that were produced without the use of antibiotics. As the global market increases for broiler production, the treatment for coccidiosis control still mainly relies on a drug such as an ionosphere or chemicals. The speaker presented the commercialization of the Rotam-CS which was identified and isolated from the plant Bidens Pilosa against coccidiosis, in terms of branding, pricing, registrations, and import license as well as a global strategic alliance for NDA in Asia and Latin America.
S3-2 Scutellaria baicalensis, which is selected to contain functional ingredients in relieving skin discomfort symptoms, is undergoing a series of verification (cytotoxicity test, functional component analysis, and cell efficacy screening) for its potential application for skin irritation, melanin content reduction, and anti-inflammation. The speaker also showed the tentative anti-inflammation effect through combining extracts of Scutellaria baicalensis and Zingiber zerumbet evidenced by the improved activity of fibroblast and keratinocytes.
S3-3 Many studies have demonstrated that probiotics could enhance the growth performance of swine, but there is rare evidence of its effect on meat quality. The speaker introduced a multi-strains probiotic, SYNLAC™LeanAd (SLA), and demonstrated its effect on growth performance, carcass characteristics, meat quality, and cecal microbiota of pigs. In addition, cecal microbiota analysis showed this multi-strains probiotic can modify compositions of gut microbiota which may potentially influence the carcass traits and meat quality.
S3-4 The speaker applied a reverse vaccinology technique to develop a novel Dendritic Cell (DC)-targeting sub-unit vaccine system, in which a subunit was thus constructed and verified in its efficacy against Porcine Reproductive and Respiratory Syndrome virus (PRRSV) in the swine industry. The experiment results showed promising effects of this protein sub-unit vaccine in pig growth performance and PRRS-caused viremia reduction. The speaker also extended this DC-targeted subunit vaccine system to other PRRV genotypes and African Swine Fever in the current R&D projects. The speaker concluded that, based on the data presented in the presentation, the DC sub-unit vaccine is an effective tool in the control of the immunosuppressive diseases based on the presentation of the protein carrier in combination with virus conserved epitopes against swine viruses.
Workshop video can be watched at:
More workshop information can be viewed in the workshop website:
Suggestions and conclusions
108 people registered for the symposium, including participants from Taiwan (77), Philippines (7), Fiji (4), Papua New Guinea (2), and other countries. Among the registrants, 65 were from the public sector, 26 from the private sector, and others from research institute and international organizations. The online symposium was mainstreamed and broadcasted on two platforms, the Cisco Webex Event (max. 1,000) and the FFTC Facebook where simultaneous translation service was provided. The 2-days Facebook video stream reached more than 650 views during the symposium, showing the successful promotion of this international symposium on the Facebook.