Effects of Bentonite, Zeolite, and Illite as Dietary Supplements for Pacific White Shrimp (Litopenaeus vannamei)

This study evaluated the effects of dietary supplementation with three silicate minerals (bentonite, zeolite, and illite) on the growth performance, whole-body composition, hematological and immune parameters, and apparent digestibility of Pacific white shrimp (<i>Litopenaeus vannamei</i>). Four isonitrogenous (35% crude protein) and isoenergetic (17.0 MJ kg^-1) diets were formulated: a control (CON) and three experimental diets containing 5% bentonite (BE), zeolite (ZE), or illite (IL), in which an equivalent amount of starch was replaced. Juvenile shrimp specimens (initial weight: 0.02 g) were reared for nine weeks and assessed for growth performance, feed efficiency, survival, biochemical indices, immune responses, and apparent digestibility. Shrimp specimens fed the illite-supplemented diet exhibited significantly higher final body weight (5.95 ± 0.97 g), weight gain, specific growth rate, and protein efficiency ratio than the other groups (<i>p</i> < 0.05). The feed conversion ratios were significantly better in the IL (1.10 ± 0.03) and ZE (1.16 ± 0.02) groups than that in the BE (1.26 ± 0.05) and CON (1.32 ± 0.04) groups (<i>p</i> < 0.05). The whole-body crude protein content was significantly higher in the ZE and IL groups. Hemolymph glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvate transaminase (GPT) activities were significantly reduced in the ZE and IL groups, indicating improved hepatic health. Non-specific immune responses, including nitro blue tetrazolium (NBT), phenoloxidase (PO), glutathione peroxidase (GPx), and lysozyme activities, were most enhanced in shrimp fed the IL diet. Apparent crude protein digestibility peaked in the IL group (93.3 ± 0.70%) followed sequentially by the CON (87.3 ± 0.92%), BE (87.8 ± 0.88%), and ZE (89.1 ± 1.11%) groups (<i>p</i> < 0.05). These findings demonstrate that dietary supplementation with illite significantly improves the growth performance, feed efficiency, hepatic condition, innate immune response, and protein digestibility of <i>L. vannamei</i>. Illite appears to be a promising candidate for functional feed supplementation aimed at enhancing productivity and health in intensive shrimp aquaculture.