Responsible use of antibiotics in the APAC region and the role of functional feed additives after antibiotic growth promoters ban
Antibiotic resistance overview in Asia pacific region
Globally huge steps are being taken in reducing the use of antibiotics, and the Asia Pacific region is also taking steps in this direction. Large swine and poultry producing countries are currently looking at how to reduce antibiotic use – and have thus also started wondering how to manage animal performance and health with a limited but properly used amount of antibiotics.
In the last decade, global meat production increased by almost 20% particularly in the Asia pacific region (APAC), where the pork and poultry industries showed the highest level of expansion. Rapid urbanization and increasing incomes have had a strongly positive effect on livestock consumption. In the APAC region, improvements in feed technology and animal production systems have contributed to the shift from extensive to intensive farming operations. However, high-density animal production operations can increase the incidence of disease in livestock. Therefore, to prevent disease, livestock are frequently fed with some antibiotics which are also used for humans. The extensive usage of these antibiotics at low levels for disease prevention (prophylaxis) and for maximizing animal productivity as antibiotic growth promoters (AGPs), to increase growth rate or production of -meat, milk, and eggs is concerning. On pig and poultry farms in the APAC region, these antimicrobials include penicillins, third-generation cephalosporins, quinolones, aminoglycosides, polymyxins and macrolides. Consequently, most bacteria become resistant to antibiotics in daily livestock operations, leading to an ineffective response to treatment. The more frequent the antibiotics are used, the faster the natural development of resistance. The resistant bacteria can then spread into the environment and enter the food supply chain. In turn, these resistant strains cause diseases in humans, putting both humans and animals at risk due to the threat of treatment failure.
Antimicrobial resistance is a global health problem. The consensus of the APAC experts is that it is dangerous and unjustifiable to use antibiotics that are related to drugs of critical importance in human medicine for 'prophylactic' administration to groups of apparently healthy animals. The implementation of responsible use of antibiotics in the APAC region has been slow compared with the EU countries that have reduced their dependency on antibiotics while maintaining a highly productive and intensive system. There is a clear regional consensus focused on reduction and responsible use of antibiotics in animal production operations.
For example, China announced that it will join the European Union in banning the use of antimicrobial growth promoters in food animal production. South Korea is the only country in the APAC region to completely ban antibiotics as growth promoters in feed after an implementation of a government directive in 2012. Thailand banned the use of antimicrobial growth promoters in 2015 and last year, the country embarked on a five-year plan to achieve a further 30% reduction. In April 2017, the Vietnamese government announced that Vietnam will eliminate the use of AGPs for food safety reasons. By 2020, prophylactic use will also be stopped. Aligned with the regional efforts, the Government of Indonesia has released a new regulation on the use of antibiotics for livestock intended for human consumption and highlighted the ban of antibiotics as feed additive or as growth promoters. On the pacific region, the government of New Zealand in 2017 finished its national antimicrobial resistance action plan ready to be applied early 2018, In late 2016, Australia published its 'First National Antimicrobial Resistance Strategy 2015-2019', which considers all sectors, not only agriculture. For pigs, it is aimed at developing and enforcing veterinary antibiotic prescribing guidelines. It will also ensure the availability of evidence-based and best-practice arrangements in antimicrobial stewardship.
The best alternative proposal to reduce the use of AGPs, is a general improvement of animal production systems (biosecurity), and banning the use of medically important antibiotics from their use in a growth promotional role in poultry and livestock.
What we have learn from the countries that already ban AGPs
The whole industry (swine and poultry) were worried about decreased productivity as well as increased disease prevalence because of the AGP ban. There were many objections and arguments continued for years until AGPs were completely. Since the ban, everyone has realized that nothing has changed and the industry realized that the efficacy of AGPs was very limited in terms of growth promotion or feed efficiency.
The experience in the EU shows that an integrated approach that includes strict government regulations, improved farm management, general animal health status and production processes are indispensable for the successful implementation of AGPs ban. Importantly, the improvement of gut health contributes to the overall health status of animals. Consequently, an appropriate vaccination scheme and a satisfactory animal management including infectious disease prevention and control program, would help to limit additional antimicrobial resistance (AMR). It would also open an opportunity for better preservation of future antimicrobials during a time when their efficacy is highly compromised. Lastly, the integration of an interdisciplinary approach (one health concept) is needed to control AMR dissemination.
Reversal antibiotic resistance
There is evidence that suggests that reversing of antibiotic resistance in bacterial populations is feasible but this is dependent on the existent resistance mechanisms including the transition route of the species. The reduction of antibiotics combined with natural compounds, such as short chain fat acids (SCFA), medium chain fat acids (MCFA) and some botanical components has shown promising effects in reducing AMR. Some natural components might play an essential role in reversing antibiotic resistance by helping antibiotics recover their therapeutic functionality that has been compromised by an exponential rise in the number of antibiotic-resistant microbial strains. One example of SCFA is butyrate which induces the expression of endogenous antimicrobial host defense peptide (HDP) that represents an alternative way to control the spread of antibiotic resistant genes. The induction of molecules HDPs that affect the membrane (or cell walls) also generate sufficient conditions for growth inhibition or trigger secretion (efflux) modification processes of microorganisms. Some phytogenic molecules, such as terpenoids, alkaloids, and flavonoids, may disrupt the pathogenesis of bacteria through antimicrobial compounds or by their ability to enhance the activity of antibiotics. For instance, it has been observed that some phytogenic fractions, in combination with antibiotics, can inhibit the resistant mechanism through which Staphylococci can evade beta-lactam toxicity. On the other hand, it has been reported that quorum sensing (cell-to-cell communication) inhibition may modulate the expression of antibiotic resistance as well as virulence genes.
Emerging opportunities for alternative feed additives
As the market has put tremendous pressure on the balance between highly productive animals and the reduced use of antibiotics, livestock and poultry producers are looking for new alternatives that can deliver the same benefits provided by AGPs. For years, functional feed additives have been gaining considerable interest because their ability to improve performance by sustaining a healthy gut environment, optimum microbiota balance in early life, and strong foundations for preventing intestinal colonization of enteric pathogens. This creates a significant opportunity for alternatives that can substitute or reduce the use of AGPs. In addition, following the ban, countries in the APAC region that export animal products, such as chicken and pork meat, will find it difficult to continue without alternative solutions.
An obvious choice is the development of alternatives to antibiotics that work via similar physiological mechanisms which may, in turn, affect microorganisms, maximizing livestock health, and growth, whilst enhancing the efficiency of feed conversion. Several different feed additives such as enzymes, prebiotics & probiotics, organic acids, plant extracts, and proprietary blends are emerging as potential alternatives to protect livestock from pathogens whilst improving growth performance. However, the general belief is that there is no direct replacement available for AGPs. Instead, a multifactorial approach and integral programs are needed.
At Nutriad, it is believed that it is possible to drastically reduce the use of AGPs in the animal production systems through an integral approach. The versatility of Nutriad products allows feed producers to drastically reduce the use of antibiotics while ensuring that their protection against pathogens remains robust. Meanwhile, Nutriad suggests a holistic animal management approach (such as appropriate treatment, strict control of antimicrobial agents, early clinical and microbiological diagnosis, and implementation of strict animal production standards) is needed to reduce AMR on animal and human health.
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Article made possible through the contribution of Daniel Ramirez, MVZ, MSc, Tim Goossens, Ph.D. and Nutriad International, Belgium