Reducing AGPs usage with Essential oils

The rapid increase of the world population generates each year a greater demand for food products that come associated with the intensification of the production of grains as well as of animal protein. Along with the technological development of animal rearing that is increasingly efficient, there are new requirements related to social issues, to food safety and to the environment arise. In recent years, the widespread use of antibiotics for the treatment of diseases in humans and animals and, also, in animal production has been raised as a matter of importance in food safety and public health. With the increase of these concerns, the animal rearing is being pointed as one of the great villains of the emergence of antimicrobial resistance.

For many decades antimicrobials have been used in animal production, mainly for swine and poultry. Known as growth promoters, they have the purpose of improving the productive performance of these animals. In this regard, they act, for example, as feed nutrient absorption improvers, improving the weight gain and feed conversion, as well as helping to reduce the occurrence of diarrhea in recently weaned and growing pigs (Hernandez, 2004). Due to the association between the emergence of super-resistant bacteria and the unrestrained use of antibiotics as performance enhancers in animal production, new restrictions on the use of antibiotics as growth promoters have been implemented. For example, in 2006 the European Union had banned the use of antibiotics as growth promoters, and its use is only allowed to treat diseases (Brugalli, 2003).

Nutrition is a key issue in animal production. As the control of antibiotic use as performance enhancer is changing worldwide and to meet market demands, it is necessary to search for alternatives to the use of these substances. Currently, there are several alternative products on the market such as enzymes, probiotics, prebiotics, organic acids and essential oils, which can generate good results if used properly. Plant extracts and essential oils have received special attention, mainly for using in poultry rearing (Krishan & Narang, 2014). Essential oils are known to have antioxidant, antibacterial, anti-inflammatory, anti-carcinogenic, digestion stimulating and hypolipidemic activities (Krishan & Narang, 2014). Essential oils are aromatic, volatile compounds synthesized by plants with antibacterial, antifungal and antiviral properties, and a repellent function to ward off insects and animals. There are several studies that document the antibacterial properties of essential oils and recognize this function in both in vitro and in vivo studies (Bento, 2013, Kalemba & Kunicka 2003, Dorman & Deans 2000, Mitsch 2004 and Tiihonen 2010). Antioxidant properties, as well as effects on the digestion physiology and GUT, are also known (Franz, 2010). The aromatic compounds and the essential oils act along the digestive tract, increasing the appetite and modulating the intestinal flora. They can be used as flavor enhancers and palatability agents, which increase feed intake by animals, thus, increasing zootechnical indexes. They may also have beneficial effects for maintaining the health of the intestinal microflora and, therefore, promoting the control of potential pathogens. Additives such as herbs and volatile oils can help control infections, leading to increased availability of essential nutrients for intestinal absorption, improving the immune response of these animals to pathogens and facilitating them to develop according to their genetic potential.

In addition to the aforementioned functions, the essential oils also have known antimicrobial activity, having an inhibitory effect on the multiplication of bacteria such as Escherichia coli, Salmonella spp. and Clostridium perfringens; as well as antioxidant effect, avoiding that lipids present in the feed undergo oxidation. Furthermore, essential oils affect the lipid metabolism in the animal, increasing the concentration of antioxidant enzymes and polyunsaturated fatty acids in different tissues.
In summary, the essential oils improve the characteristics of the feed offered to the animals, through its antimicrobial and antioxidative effect, increasing the feed shelf life. Thus, essential oils can promote the enhancement of the digestion and consequently in the performance of the animals by the stabilization of the intestinal microbiota, elevation of the enzymatic activity and better absorption of nutrients. Moreover, they can improve the characteristics of the products of animal origin since the products present better oxidative stability. Considering the wide range of functions and beneficial effects that essential oils can offer, they can be an excellent alternative to the use of antimicrobials as growth promoters, meeting both regulatory and market requirements, and raising the quality of products of animal origin.

Article writen for XVET by Mariana Oliveira, DVM.

References

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