Abstract
Since the middle of the last century, the use of antibiotic growth promoters in feed has improved the performance of several food-producing animal species. However, bacterial resistance to these drugs threatens public health and has led to their prohibition in animal feed. This has increased enteric problems in broilers and consequently the use of antibiotics for therapeutic purposes. In this context, several alternatives to antibiotic growth promoters have been proposed, among them organic acids, which, according to their physical and chemical properties, modify the composition of the intestinal microbiota, whose metabolites, such as short-chain fatty acids, favor the intestinal morphology, physiology, integrity, and immunity, aspects that contribute to maintain the health of this organ and increase the bioavailability of nutrients and, ultimately, to improve the productive response of birds. This review describes the main characteristics of the organic acids commonly used in the poultry industry, their mechanisms of action and their effects, individually, in combinations of organic acids or with bioactive, on the microbiota, their metabolites, and how this affects the intestinal health and productive performance of broilers under different sanitary and environmental conditions, as well as factors that potentially interfere with the activity of organics acids.