The production of antibiotic-free chickens is a global trend: The use of growth-promoting antibiotics has been banned or regulated by some countries, and, many consumers are increasingly avoiding foods containing antibiotics. In view of this regulation of antibiotics, the demand for organic products that ensure food safety has increased, and there is a great interest in using natural alternatives to Growth Promoting Additives, in order to maintain both animal performance and welfare.

Antibiotics as growth promoters have been an excellent option for controlling gastrointestinal diseases in production animals over the past 50 years. However, negative publicity, market demand and observed marketing opportunities indicate that the poultry industry should implement antibiotic-free production as growth promoters.

Many poultry companies worldwide already have good experiences with antibiotic-free systems, while some other producers still face difficulties in controlling various health challenges, as well as the transition in infrastructure, changes in feeding and management programs, since these measures implemented to control factors that can affect the intestinal health of birds, imply additional costs.

Antibiotic-free systems can be cost-effective, if the prices of the final product cover the costs involved in the investment needed to develop them.

One of the common mistakes in antibiotic-free poultry production is to think in terms of gut disease control. In general, attention is given to coccidia or certain enterobacteria such as Clostridium or Salmonella as the main health problems in poultry. However, these would be the consequences and not the causes of the main problem.

Excess nutrients in the gut, either due to high levels of nutrients in the diet or low digestibility, cause microbial growth in the gut. Excess nutrients, especially protein and fat, are not well digested or absorbed at the end of each feeding phase. This increases microbial proliferation in the cecum.

Adequate digestibility can be achieved and maintained if the diet does not contain too many nutrients. In this way, microorganisms and the diseases they generate can be controlled. Therefore, for a low or free production of antibiotics, it is necessary to make feeding in phases, or increase the phases that currently exist, to improve the accuracy in the formulation of the balanced feed, according to the needs of the animal.

Exogenous enzymes have been adopted on a wide scale, due to their impact on reducing costs in diet formulation and their positive effect on productivity, as they reduce microbial proliferation by decreasing non-digestible components of the food or irritation of the intestinal mucosa. Enzymes also generate metabolites that promote microbial diversity, allowing for a more stable intestinal microbiota, which is more likely to inhibit the proliferation of pathogens.

Some food additives and mineral levels can help maintain healthy gut microbiota. These include probiotics, prebiotics, enzymes, organic acids and essential oils, plant and spice extracts and phytobiotics:

– Probiotics provide live microorganisms beneficial to the gastrointestinal tract

– Prebiotics promote the growth of bacteria beneficial to the gastrointestinal tract.

– Enzymes help to eliminate the anti-nutritional effects of water-soluble polysaccharides and/or alter substrates to enhance the growth of certain beneficial bacterial communities.

– Organic acids inhibit bacterial growth.

– Essential oils, plant extracts and phytobiotics can support the balance of the microbiota, stimulate the production of digestive enzymes and the immune system.

The category of phytobiotics, plant extracts and essential oils are a blend of phytochemicals with specific antimicrobial properties that have shown promising results in reducing colonization and proliferation of Clostridium perfringens and controlling coccidia infections, thereby helping to reduce necrotic enteritis. In addition, the combination of these essential oils with benzoic acid has been shown to reduce mucin production in the small intestine of broilers.

Some studies carried out by the Faculty of Veterinary Medicine and Zootechnics of the National Autonomous University of Mexico have even concluded that the use of a natural product based on plant extracts and essential oils or plant alkaloids in the chicken diet results in a behavior similar to that of antibiotic growth promoters (Colistin + Bacitracin zinc or Bacitracin zinc), resulting in these products being an alternative in poultry farming.

Reducing the use of antibiotics or their responsible and careful management by veterinarians involved in animal production will be increasingly critical and will require adherence to the principles of good administration and responsible use.