Recent advances in the role of organic acids in poultry nutrition

In recent years, there has been an increase in the use of organic acids as substitutes for antibiotic growth promoters because of the fear of antibiotic resistance and the implications for human health. Organic acids and their salts have been used in poultry diets and drinking water for decades and seem to elicit a positive response in growth performance. An important objective of dietary acidification is the inhibition of intestinal bacteria competing with the host for available nutrients, and a reduction of possible toxic bacterial metabolites resulting in the improvement of nutrient digestibility, thereby ameliorating the performance of birds and enhancing the specific and non-specific immunity in poultry. Literature shows that short-chain fatty acids, medium-chain fatty acids and other organic acids have more or less pronounced antimicrobial activity, depending on both the concentration of the acid and the bacterial species that is exposed to the acid. The possible mechanisms contributing to these effects and the factors thought to explain the variability in these responses are discussed. This paper provides a review of the use of organic acids in the prevention of enteric disease in poultry, the effect on the gastrointestinal tract, nutrient digestibility, immunity and performance of broiler and laying hens.