Long-term effect of reduced AGP usage: a worldview

Additive supplier Alltech conducted a survey of the global use of antibiotic growth promoters - and the results of its restriction - in livestock production.

A recent survey of 128 countries sponsored by Alltech reviewed the growing restrictions on the use of antibiotics as growth promoters. The survey focused on the 59 countries where restrictions exist or are likely to be implemented, including 28 from the European Union and the top seven countries in terms of livestock production.

General practices of antimicrobial use in food animals

There are four applications for antibiotics in animals: therapeutic, prophylaxis, metaphylaxis and growth promotion. Overuse of antibiotics is increasingly viewed as one of the potential drivers for microbe resistance, although the evidence linking antibiotic use in farm animals with resistance in humans is still controversial.

Reducing the use of antibiotics in animal production became an important objective for the European Union in the late 1990s. Since promoting growth involves the continuous consumption of antibiotics, this practice was completely banned in the EU on January 1, 2006. Several countries had made the choice before a formal ban, including Sweden (mid 1980s) and Denmark (1996). Since then, New Zealand (1999), Chile (2006), Bangladesh (2010) and Korea (2011) have followed suit.

Although AGPs have been banned in many markets, many continue to allow three antibiotic uses: therapeutic, prophylaxis and metaphylaxis. Scandinavian countries have already gone one step further by forbidding all antibiotics for animals except therapeutic use.

Antibiotic usage: Restrictions apply

Restrictions on antibiotic applications may occur through national standards but many countries now also have other voluntary standards. This allows companies to address niche markets, involving decreased use of antibiotics, and these markets are developing quickly in developed countries. Increasingly the meat industry is actively embracing them.

In the United States, 9 percent of the total broiler chicken production is now antibiotic-free as reported on NPR, and 2 percent of the layers and nearly three percent of the milking cows were U.S organic certified animals in 2011. The livestock industry from export countries now has developed “export” standards that fit with the customer country. For example, the Thai and Brazilian poultry industry have entire sections of their value chain follow the EU regulations to allow exports to that market.

In developing countries, however, there are no regulations that frame the use of antibiotics in animal production. The OIE is currently working with the U.S. Food and Drug Administration (FDA) and the World Health Organization (WHO) to help developing countries improve their legislation covering the control, distribution and use of veterinary antimicrobials.

In 2001, the World Organization for Animal Health (OIE) member countries in Africa identified lack of legislation, knowledge, resources and veterinary services as obstacles to the prudent use of antimicrobial drugs.

Three distinct consequences of the AGPs ban

The Alltech survey specifically focused on the use of AGPs in compound feed and the aftermath of bans and restrictions on their use in several countries. Here are three outcomes deduced from its findings:

1.Did production performance decrease after the ban of AGPs?

A small, but temporary decrease in performance was noted post-ban in Spain, Denmark, Greece and Finland, while Bangladesh, Korea, Romania and the Netherlands have reported no effects on animal performance.

In Denmark, reports indicate that the cost of production per pig produced increased by approximately 1.0 Euro with a high degree of variability between pig producers and phase of production. Temporary negative effects occurred during the post weaning period (7 to 30 kg), however no or limited effect were found in the finisher production (>25 to 30 kg).

For broilers there was no significant negative effect on animal health, welfare or production costs. In South Africa, trials conducted with AGP-free diets were reported to have had mixed results.

2.What did producers do after the ban of AGPs to get the same level of production?

In New Zealand, where they officially banned of AGPs in 1999, the same antibiotics were re-registered for disease prevention and treatment. This strategy, at least for a short transition period, was supported by the veterinarians. The same was reported in Bangladesh, Denmark, Finland, France and the Netherlands. (Figure 1)

The first consequence of the ban is that good husbandry management practices had to be reassessed. This means hygiene, batch management, cleaning, disinfection and feed hygiene but also basic nutrition and vaccination plans. The Danes have emphasized the need for more digestible raw materials, especially for piglets. Stocking density also had to be decreased. A long, growing list of compounds has been tested for their ability to replace antibiotics as feed additives in animal diets. This list includes, amongst others, probiotics, prebiotics, acidifiers, plant extracts, essential oils, nutraceuticals, medium chain fatty acids, enzymes, antimicrobial peptides, clay minerals, egg yolk antibodies and rare earth elements.

Unfortunately, the vast majority of these compounds produce inconsistent results and rarely equal antibiotics in their effectiveness. 

The search for effective alternatives to AGPs has been hampered by a lack of knowledge about the mechanisms of AGP-mediated growth enhancement. In New Zealand, only Mannan Rich Fractions (MRF) have been reported to show enough promise and are used by the poultry industry. 

Dr. Steve Collett, of the Poultry Diagnostic and Research Center (PDRC) at the University of Georgia, has demonstrated the benefits of a program, "Seed, Feed and Weed," in improving gut health and feed efficiency. The program consists of applying specific strains of clostridia, excluding probiotics, in the hatchery to seed the gut, while feeding bioactive yeast carbohydrates (MRF) and weeding using organic acids in the water and enzymes to reduce non-digestible feed fractions that may cause the proliferation of clostridia. In the absence of antibiotics, a key factor in maintaining an optimal gut microflora is also to control the flow of nutrients down the gastrointestinal tract.

3.Did meat, eggs and milk importation increase after the ban?

AGP restrictions haven’t resulted in increased importation of animal proteins, except for Denmark. Interestingly countries haven’t stopped importing protein food from countries that didn’t ban antibiotics Similarly, importation of U.S. beef using ractopamine to South Korea continued even the country forbade its use for its own beef production.
The report, “Competitiveness of the EU poultry meat sector,” released in December 2013 by Wageningen University stated that costs were 71 to 72 percent of that level in Argentina & Brazil, and 80 to 84 percent in the United States and Thailand.
U.S. broiler producers who switched to natural antibiotic-free production also changed to animal protein-free diets and reduced the stocking density. Understandably, both measures can affect the cost of production. This function of improved farm management, nutrition and research allied to import levies continue to protect the EU from these competitive pressures.

Successful reduction of overall antibiotic used in livestock…. So what’s next?

The ban of antimicrobial growth promoters has resulted in a considerable decreased use of antimicrobials in food animal production as measured in kilograms of active ingredient, specifically: Sweden, -65 percent; Denmark, 47 percent; Norway, -40 percent; and Finland, -27 percent. In France, the overall volume of antibiotics in animal production diminished by 33 percent between 2007 and 2012.   

In Denmark, it resulted in another system created by the government in 2002, called DANVET, to tightly control the usage of therapeutic medicine for livestock animals at herd and veterinarian level. The Netherlands and France implemented an auto-control system, which gave the responsibility to the veterinarians and the industry to self-regulate the antibiotic consumption.

Proper management optimizes gut health

While the impact on anti-bioresistance is more complex than expected, it adds to the rise in production costs of animal protein. The EU animal livestock industry has still moved forward despite the ban and is still producing high-quality animal proteins applying available knowledge and tools.

The complete optimization of gut health on every single farm isn’t possible using a unique component or intervention. Summarized by Collet as the “Seed, Feed and Weed” approach, strategies to improve gut health in commercial operations need to be cost effective, sustainable, farm specific and holistic.

Intervention/product selection needs to be science-based but practical, and each intervention must address the specific objective for its inclusion. Customized approaches to gut health are needed, keeping in mind that the principles of good husbandry are the very necessary foundations of gut health, and programs not products will be the key.


References available upon request.

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