Ban on AGPS and the impact on the Asian Poultry Industry

As the European Union moves closer toward implementing its ban on the remaining feed grade antibiotics growth promoters in January 2006, the Asian poultry markets are on their toes and closely observing the situation in the EU, realizing that this change is inevitable. As a result, the scene in Asia has been set not to simply sit back and await this expected transformation, but rather, to participate by embracing this change in the best way possible, that is to prepare itself to follow suit.

The new regulations will strengthen the control of all types of additives in animal feed, but in particular it completes the EU's drive to phase out antibiotics as growth promoters. Banning the use of antibiotics as growth promoters in feed is also vital in efforts to combat antibiotic resistance.

The leading poultry integrators in Asia who are proactive and who want to remain competitive in this fast-changing industry have currently stepped up their research and development efforts in an effort to better understand their disease problems, to improve their nutrition, management, hygiene and biosecurity and to minimize any impact lest the Asian poultry industry should mimic their European counterparts in the near future.

Asian poultry integrators have been using antibiotic growth promoters for many decades, and have grown to be dependant on such substances, so much so that they would feel crippled and unable to raise their birds if these were ever taken away from them.

But what is the actual function of these antibiotic growth promoters? Their basic mode of action is to inhibit the growth of pathogens in the gastrointestinal tract. This leads to more efficient feed utilisation, better nutrient absorption and enhanced growth rates. In gnotobiotic animals with no microbiota present in the intestines, antibiotic growth promoters cease their activity and benefits. This shows that they needed bacteria to be present to have an effect. In this way, they are able to prevent these pathogens from causing gastrointestinal tract disease.

So whilst many producers are content with the usage of antibiotic growth promoters as long as it is not prohibited by legislation and regulations, there are the exceptional few who have made preparations for its phasing out in the livestock industry, by searching and researching for various possible alternatives. And while the exclusion of antibiotic growth promoters in Asia may be years or even decades away, many Asian producers have stepped ahead of their counterparts in embracing the concept of food safety and better public health, pioneering in aspects of antibiotic-free meat and eggs, and advocating the reduction of antibiotic usage to thus prevent the development of antibiotic resistance in bacteria.

The potential of oregano as a natural herb to replace antibiotic growth promoters has been long overlooked. Oregano-based feed additives have been used in worldwide poultry production even before the EU decided to impose its ban on antibiotic growth promoters. Oregano essential oil has been extensively researched and tested, and is able to increase the performance of poultry production by improving the Feed Conversion Ratio (FCR) as well as increasing the body weight gain of broilers. It also helps to reduce mortality caused by gastrointestinal diseases by preventing the occurrences of gastrointestinal pathogen invasion.

The phenolic compounds within oregano oil, carvacrol and thymol (Adam et al., 1998) effectively kill these microorganisms, which include both gram positive and gram negative bacteria (Stiles et al., 1995) upon contact, within the gut of the animals (Sivropoulou et al., 1996). The phenolic effect is through their activity on the bacterial cell wall, by denaturing and coagulating the protein within the cell wall structure. More specifically, phenols interact with the cytoplasmic membrane by changing its permeability for cations, like H(+) and K(+). The dissipation of ion gradients leads to impairment of essential processes within the cell, causing leakage of cellular constituents, which result in water unbalance and finally cell death (Heipieper et al., 1991). In contrast to antibiotic growth promoters, there has been no evidence of bacterial resistance from using oregano oil (Ingram, 1997).

Coccidiostats too, will be banned as feed additives by year 2011. Coccidiosis is an age-old problem that can result in subclinical syndromes such as impaired feed conversion, poor flock uniformity and poor performance; or clinical effects such as enteritis, diarrhoea and even death (Ekstrand et al., 1994; Waldenstedt, 2001; Youn and Noh, 2001). Coccidiosis is considered as one of the most severe health and welfare problems in poultry that costs a huge loss to poultry producers worldwide (Stevens, 1998). The continuous use of anticoccidials and the many types of ionophores in commercial poultry-rearing has also led to development of resistance and has given rise to multiple drug-resistant strains of coccidia in the field. But now the problem can be solved by the use of oregano essential oil.

Oregano essential oil can be used to control coccidiosis in all phases of poultry production. To effectively control coccidiosis, the phenolic compounds within oregano speed up the process of the normal shedding of enterocytes from the intestinal mucosae (Ultee et al., 1999; Weber and De Bont, 1996), causing a disruption in the life cycle of Eimeria spp. and as a result, the protozoa are not able to complete its life cycle to cause either clinical or subclinical disease. Besides effectively controlling coccidiosis, the usage of an alternative such as oregano essential oil will eventually lead to a reduced usage of coccidiostats and thus prevent coccidia from developing resistance, which is a problem faced by many who still use coccidiostats to control the disease.

In Turkey, oregano products are very popularly used to replace antibiotic growth promoters and coccidiostats in the broiler production cycle. In a commercial field trial that was conducted in a large poultry integrator in Bolu, such an oregano-based product (Orego-Stim^®, Meriden Animal Health Ltd.) was used during the withdrawal feed period. During this phase, antibiotic growth promoters and anticoccidials are excluded from the poultry feed.

Prior to the inclusion of the oregano-based product, the birds were suffering from pasty vent and blood-stained droppings, typical of a mixed coccidiosis and necrotic enteritis infection.

These clinical signs were present despite the inclusion of antibiotic growth promoters and coccidiostats before the withdrawal feed period.

In their place, oregano was able to perform its function of providing growth-enhancing and anticoccidial properties as well as having extra benefits for the birds, such as resolving the diarrhoea, reducing mortality, improving feed efficiency and increasing the performance of the treatment group. Thus, this resulted in a higher profitability for the broiler producers.

In the Philippines, Professor Marcela Batungbacal from the Institute of Animal Science, UPLB found that oregano extract (Orego-Stim, Meriden Animal Health Ltd.) was more effective in controlling oocyst production compared to amprolium. Amprolium has been found to be highly effective against Eimeria tenella and E. necatrix but less effective against E. acervulina, E. maxima and E. brunetti, but the mode of action of oregano extract was not species-selective in controlling and preventing coccidiosis.

Coccidial vaccines are commonly used in breeder operations and can usually provide adequate protection against coccidiosis. However, they may not be the perfect solution due to certain post-vaccination reactions that may occur during the 3rd to 4th week after vaccination and also the emergence of necrotic enteritis, an enterotoxaemic disease that usually accompanies coccidiosis, caused by Clostridium perfringens.

Waldenstedt (2001) investigated the effects on production and health in broilers vaccinated against coccidiosis with a commercial vaccine (Paracox^®, Schering-Plough) in combination with an oregano-based product (Orego-Stim^®, Meriden Animal Health Ltd.). The results of her study indicated that vaccination against coccidiosis in combination with the oregano-based product proved a better method of controlling both coccidiosis as well as necrotic enteritis.

Sweden is widely cited as the first country to stop using antibiotic growth promoters (AGPs).  In 1986, Sweden became the first European country to ban non-therapeutic use of antibiotics in response to pressure from the Swedish Farmers Union and consumers. In Sweden, the occurrence of necrotic enteritis increased dramatically following the ban. Intestinal colonisation by Clostridium perfringens not only decreases growth and feed utilization, but can also result in high mortality.

This is where the wonders of oregano come in and play its role. With the implementation of a proper combination programme, oregano-based products can safely and effectively be positioned in combination with coccidial vaccines. Clostridium perfringens is easily destroyed upon contact by the phenolic compounds of oregano essential oil. With such an application scheme, the incidence of coccidiosis and necrotic enteritis in poultry can easily be controlled and reduced effectively.

However, we must note that not all oregano products work the same. The efficacy and activity of Orego-Stim is due to the unique matrix of the components found in it, but the major components of Orego-Stim are still carvacrol and thymol, which make up about 85% of the active components. The level of carvacrol and thymol in Orego-Stim is in a very specific range. This specific ratio between carvacrol and thymol plays a major role in its antibacterial, antifungal, antioxidant and growth enhancing activities.

A constant worry of using essential oils would be the degree of inconsistency in the amount of active ingredients contained within them. Most companies that produce oregano products in an attempt to take advantage of the EU ban on AGPs have resorted to using oregano grown and harvested from the wild, sourced from different Mediterranean countries. In a further attempt to compensate for the deficiency in natural phenols, these companies may resort to the usage of synthetic phenols, which are cheaper and easier to produce, but contain traces of toxic substances and carcinogens. This is not in line with the global demand for safer and healthier meat and eggs.

Orego-Stim is the world's leading product in the field of naturals, a product of blending science and nature. A product that would help to sustain intensive livestock-rearing in a competitive environment and be able to see through all the changes in legislations to reach a common goal of promoting healthy animals for healthy people the natural way.

1. Adam, K., Sivropoulou, A., Kokkini, S., Lanaras, T. and Arsenakis, M. (1998) Antifungal activities of Origanum vulgare ssp. hirtum, Mentha spicata, Lavandula angustifolia, and Salvia fruticosa essential oils against human pathogenic fungi. J. Agric. Food Chem. 46, 1739-1745.

2. Ekstrand, C., Algers, B., Thebo, P. and Hooshmand-Rad, P. (1994) Rearing broilers without coccidiostats. Proceedings of the Eighth International Congress on Animal Hygiene, Minnesota, USA, 67-70.

3. Ingram, C. (1997) The Cure is in the Cupboard (How to use Oregano for Better Health). Publisher: Knowledge House, Illinois.

4. Sivropoulou, A., Papanikolaou, E., Nikolaou, C., Kokkini, S., Lanara, T. and Arsenakis, M. (1996) J Agrc Food Chem.: 44; 1202-1205

5. Stevens, D.A. (1998) Coccidiosis. In: Delves, P. J., Roitt, I. M. (Eds.), Encyclopedia of Immunology, 2nd Edition, vol I, Academic Press, London, pp. 591-593.

6.  Stiles, J. C., Sparks, W. and Ronzio, R. A. (1995) J Appl Nutr. 47: 96-102.

7. Ultee, A., Kets, E. P. W. and Smid, E. J. (1999) Mechanisms of action of carvacrol on the food borne pathogen Bacillus cereus. Appl. Environment. Microbiol. 65, 4606-4610.

8. Waldenstedt, L. (2001) Rearing broilers without growth promoters and coccidiostats. Proceedings of the XXI Worlds Poultry Congress, Ontario, Canada.

9. Weber, F. J. and De Bont, J. A. M. (1996) Adaptation mechanisms of microorganisms to the toxic effects of organic solvents on membranes. Biochim. Biophys. Acta 1286, 225-245.

10. Youn, H. J. and Noh, J. W. (2001) Screening of the anticoccidial effects of herb extracts against Eimeria tenella. Vet. Parasitol. 96, 257-263.

11. Batungbacal M. R., Luis E. S., Centeno J. R. and Carandang N. F. (2004) Oregano extract: an alternative anticoccidial and performance enhancer for broilers. Unpublished report.