Recently, condensed tannins (CT) have been considered as a functional feed additive in the aquafeed industry, as they have antioxidant and anti-inflammatory properties leading to improved gut health, and ultimately enhance the nutrient utilization and overall performance of shrimp. Hence, this study aimed to evaluate the effects of dietary supplementation of increasing levels of CT on the performance, oxidative status, and meat quality of Litopenaeus vannamei . The experiment consisted of two phases , nursery and grow-out, and was conducted under controlled conditions at the Aquaculture Sector of UFERSA (Mossoró, Brazil), using low-salinity water (3 ppt).
In Phase 1 (nursery phase), the post-larvae were stocked in 500-L tanks and fed four experimental diets, i.e. , basal diet, and three additional basal diets supplemented with CT (SetaGuard® Aqua) 50g, 150g, and 250g per ton feed for 28 days. Feed intake, growth performance, and feed conversion ratio were significantly affected by dietary treatments . Based on quadratic response , the optimal dose of CT for growth and FCR were 129.02 g/t, and 162.5 g/t, respectively .
In phase 2 (grow-out phase), the shrimp juveniles were fed four experimental diets i.e., 0g, 50g, 150g, and 250g CT per ton of feed, for 70 days. The highest final weight was observed at 50 g/t, with body weight uniformity highest at 124.83 g/t. Shrimp length improved significantly at 50 g/t, with higher tannin levels promoting weight uniformity compared to the control. Maximum weight gain and optimal FCR were recorded at 50 g/t, while survival rates showed no treatment effects.
In conclusion, the recommended dose of CT is 150 g/ton and 50 g/ton for the nursery phase and grow-out phase, respectively . These findings support the strategic use of condensed tannins as functional additives for sustainable shrimp production.