Introduction: Aquaculture is currently the fastest-growing sector of animal protein production, playing a vital role in global food security. However, challenges such as rising feed costs, disease outbreaks, and restrictions on antibiotic growth promoters have intensified the need for alternative feed additives. Organic acids and their salts have gained significant attention due to their multifaceted benefits including antimicrobial properties, enhancement of nutrient digestibility, immune stimulation, and environmental sustainability. This extended abstract provides an overview of the current knowledge regarding the use of organic acids in aquaculture, summarizing their mechanisms of action, potential benefits, limitations, and future research directions.
Methodology: This review article is based on a comprehensive analysis of published peer-reviewed papers, conference proceedings, and experimental reports that investigate the dietary application of organic acids in finfish aquaculture. Studies included were selected based on their relevance to fish growth performance, digestive physiology, immune modulation, and microbial balance. Both freshwater and marine aquaculture species such as tilapia, rainbow trout, carp, and seabream were considered. Attention was also given to comparative differences among carnivorous and omnivorous fish species to highlight species-specific responses.
Finding: Organic acids such as formic, acetic, propionic, butyric, citric, lactic, and malic acids have been widely tested as dietary additives in aquaculture. Their mechanisms of action are diverse, including the reduction of intestinal pH, suppression of pathogenic bacteria, stimulation of digestive enzymes, and improvement in mineral bioavailability. Research demonstrates that supplementation with these acids improves feed utilization, enhances weight gain, and reduces feed conversion ratio (FCR). For instance, sodium butyrate has been reported to nourish intestinal epithelial cells and improve immune responses, while citric acid improves calcium and phosphorus absorption. Beyond growth performance, organic acids also contribute to microbial balance by suppressing harmful species such as Escherichia coli and Vibrio spp. while promoting beneficial bacteria such as Lactobacillus spp. Their immunomodulatory effects include increased white blood cell counts, activation of macrophages, and upregulation of immune-related genes like IL-1β and TNF-α.
Nevertheless, there are challenges associated with their use. Excessive supplementation, particularly with formic and propionic acids, can cause hyperacidity leading to intestinal mucosal damage and reduced enzyme activity. Species-specific differences are also evident; carnivorous fish such as rainbow trout and cobia generally tolerate organic acids better due to their highly acidic stomachs, while omnivorous species such as Nile tilapia, which have weaker gastric buffering, are more prone to negative effects. Additionally, legal regulations on permissible levels of organic acids in feed differ between regions, complicating their universal adoption.
Conclusion: In conclusion, organic acids offer great promise as sustainable alternatives to antibiotics in aquaculture, with proven benefits for growth, nutrient absorption, microbial balance, and immune defense. Their potential role in improving product quality and reducing the environmental impact of aquaculture systems also makes them attractive for future development. However, the variability of responses among species, risks associated with overdosing, and regulatory challenges highlight the need for species-specific formulations and carefully designed feeding protocols. Future research should focus on clarifying molecular mechanisms, developing encapsulation technologies to improve stability, and evaluating long-term safety under commercial farming conditions. With targeted applications, organic acids can significantly enhance the sustainability and profitability of modern aquaculture.
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