Effects of plant-origin binder sources in Asian catfish diets on growth, feed quality, blood chemistry, liver and gut health, and economic efficiency

Natural polysaccharides have demonstrated considerable potential as binding agents in aquafeed formulations, enhancing water stability and reducing nutrient leaching and pellet disintegration in aquatic environments. In this study, four isoproteic diets (32% crude protein) were formulated using different binders: carboxymethyl cellulose (D₀, control), purple fingerling potato (D₁), taro root (D₂), and glutinous rice (D₃). Each diet was administrated to Asian catfish (Clarias batrachus) (mean initial weight: 6.66 ± 0.01 g) over a 90-day trial to evaluate growth performance, feed stability, whole-body composition, health parameters, and economic feasibility. The results indicated that binder type significantly affected pellet durability index, floatability, and swelling rates (p < 0.05). Notably, fish fed the D₂ diet exhibited significantly higher (p < 0.05) feed attractability and palatability. Growth performance metrics, including final weight, weight gain, total biomass, specific growth rate, feed conversion ratio, and protein efficiency ratio, varied significantly (p < 0.05) among dietary treatments, with the D₂ group demonstrating the most favorable outcomes. Additionally, fish from the D₂ group exhibited significantly higher (p < 0.05) crude protein levels lower crude lipid content in whole-body composition. The dietary binders also had significant impact (p < 0.05) on hemato-biochemical indices, except for monocyte levels. Histological analysis indicated that fish in the D₂ and D₃ groups exhibited improved intestinal structure, characterised by increased villi length, a higher density of goblet cells, and an elongated lamina propria. In contrast, fish fed the D₀ and D₃ diets displayed increased vacuolar cytoplasm and degenerative nuclei. Furthermore, economic analysis revealed that the D₂ diet significantly enhanced economic efficiency (p < 0.05) compared to other treatments. In conclusion, incorporating taro root as a binder in the diet of Asian catfish (D₂) improved growth performance, feed stability, health status, and economic returns, making it a promising alternative to conventional binders.