Organic Acids and Potential for Modifying the Avian Gastrointestinal Tract and Reducing Pathogens and Disease

Abstract

Recently, antibiotics have been withdrawn from some poultry diets; leaving the birds at risk for increased incidence of dysbacteriosis and disease. Furthermore, mortalities occurring from disease contribute between 10 to 20% of production cost in developed countries. Currently, numerous feed supplements are being proposed as effective antibiotic alternatives in poultry diets, such as prebiotics, probiotics, acidic compounds, competitive exclusion products, herbs, essential oils, and bacteriophages. However, acidic compounds consisting of organic acids show promise as antibiotic alternatives. Organic acids have demonstrated the capability to enhance poultry performance by altering the pH of the gastrointestinal tract (GIT) and consequently changing the composition of the microbiome. In addition, organic acids, by altering the composition of the microbiome, protect poultry from pH-sensitive pathogens. Protection is further provided to poultry by the ability of organic acids to potentially enhance the morphology and physiology of the GIT and the immune system. Thus, the objective of the current review is to provide an understanding of the effects organic acids have on the microbiome of poultry and the effect those changes have on the prevalence of pathogens and diseases in poultry. From data reviewed, it can be concluded that the efficacy of organic acids on shifting microbiome composition is limited to the time of administration, the composition of the organic acid product, and the current health conditions of poultry.

Probiotics and Its Potential Role in Poultry Production: A Review

“…In addition, Wang et al 37 showed that lactic acid could even completely inhibit growth of pathogens inclusive of E. coli, Salmonella and L. monocytogenes. The others include physical blocking of available bacterial receptor sites 32,38,39 ; compete with pathogenic bacteria for essential nutrients and energy source; secretion of antimicrobial substances and release of selective gut protective metabolites like arginine, glutamine, short-chain fatty acids and conjugated linoleic acids. 35,40…”

“…The common mechanisms of bacteriocin-mediated killing include the destruction of target cells by pore formation and/or inhibition of cell wall synthesis. 39,40…”

“…Probiotics are proposed to increase the length of villi by activating cell mitosis and induce gut epithelial-cell proliferation. 39,48,54 Increased villi height by probiotics is beneficial to the broilers as the increased surface area of the villi enhanced the absorption of nutrients. It has been suggested that alteration in villi length and crypt depth may lead to poor nutrient absorption, digestive enzymes secretion in the GI tract and eventually lower growth performance in broilers.…”

Source of Water and Potential Sanitizers and Biological Antimicrobials for Alternative Poultry Processing Food Safety Applications

“…In addition to SCFAs, organic acids also entail medium chain fatty acids (MCFAs) which are 6 to 12 carbons in length, and long chain fatty acids (LCFAs ≥ 13C) (Beermann et al, 2003). Short chain fatty acids are produced in the gastrointestinal tract (GIT) of chickens and humans and have been extensively studied as potential poultry GIT modifiers for pre-harvest intervention as animal feed additives (Cherrington et al, 1991;Ricke, 2003;Van Immerseel et al, 2006;Dittoe et al, 2018a). These fatty acids have also been utilized as sanitizers, although less information is available from the literature.…”

“…Lauric and myristic acids inhibit Clostridium perfringens at concentrations of 0.1 to 0.2 mg/ml (Skrivanová et al, 2006). However, the lipopolysaccharide layer of Gramnegative bacteria has been shown to elicit resistance against MCFAs and LCFAs by preventing the fatty acids from crossing the cell membrane (Sheu and Freese, 1973;Cherrington et al, 1991;Dittoe et al, 2018a). Citric acid, another organic acid, has been shown to inhibit C. perfringens at a concentration of 4 mg/ml and has antimicrobial properties against Gram-negative bacteria (Skrivanová et al, 2006;Over et al, 2009;DoleŽalová et al, 2010).…”