Nutraceuticals Used as Antibacterial Alternatives in Animal Health and Disease

Abstract

In the past decades, an accumulative amount of research has been concentrated on the development of alternatives to antimicrobials to maintain animal welfare and health and performance. A high level of internal and external biosecurity for farms, herds, or flocks is critical because they constantly receive and deliver biological material. Many efforts have been dedicated to demonstrate how viruses or bacteria are shed from poultry or pigs and transmitted among farms, herds, or flocks. A good external biosecurity is crucial to avoid introduction of new biological agents. To overcome the increased rate of mortality and morbidity resulting from the ban of in-feed antibiotics, a number of antibacterial alternatives have been designed. The classes of alternative substances described in this chapter include organic acids and short- and medium-chain fatty acids, phytobiotics and essential oils, antimicrobial peptides, bacteriophages and their endolisins, and immunomodulatory compounds (vaccines). Prebiotics and probiotics, and enzymes, are also notable alternatives to antibacterials but are described in two other chapters. These nutraceuticals are valuable tools in antibiotic-free production systems to support the intestinal health of the animal. Based on a literature search, it is evident that a long and growing list of compounds have been reported for their ability to replace antibacterials as feed additives in animal diets. Research is still needed in the area of nutraceuticals used as antibacterial alternatives in animal health because the perfect alternative to antibacterials does not yet exist. The mechanism of action for these compounds needs to be better defined. Regulations concerning feed additives in the European Union for these nutraceuticals used in animal production are also described.