The Roles of Polysaccharides in Carp Farming: A Review

SIMPLE SUMMARY: Disease outbreaks pose a major challenge for farmers in sustaining carp farming. Antibiotics and chemicals are the conventional solutions to improve carp growth and health performance. Nonetheless, the consistent use of antibiotics as an antimicrobial agent in aquaculture could lead to pathogen resistance, harm the beneficial gut microorganisms and environment, and cause the build-up of excess antibiotics in the fish muscle that is dangerous to humans. Alternatively, polysaccharides could improve growth performances, active innate immunity and disease resistance, and alleviate abiotic stress in carp and other aquatic species. The application of polysaccharides in carp farming varies depending on the dosage and combination with other agents. Therefore, a comprehensive study is essential to reveal the molecular and cellular pathways that regulate the immune responses of carp to different pathogens and abiotic stressors. ABSTRACT: Carp is an important aquaculture species globally, and the production is expected to increase with the growing market demands. Despite that, disease outbreaks remain a major challenge, impeding the development of sustainable carp farming. Moreover, the application of antibiotics, a common prophylactic agent, can adversely impact public health and the environment. Therefore, polysaccharide has been recognized as a novel prophylactic agent in the health management of carp farming, as well as gaining consumers’ confidence in carp farming products. In this review, the definition, sources, and main roles of polysaccharides in improving growth performance, stimulating the immune system, enhancing disease resistance, and alleviating abiotic stresses in carp farming are discussed and summarized. In addition, the use of polysaccharides in combination with other prophylactic agents to improve carp farming production is also highlighted. This review aims to highlight the roles of polysaccharides and provide valuable information on the benefits of polysaccharides in carp farming.