Can dietary β-carotene supplementation provide an alternative to astaxanthin on the performance of growth, pigmentation, biochemical, and immuno-physiological parameters of Litopenaeus vannamei ?

The present study aimed to investigate the effect of dietary beta-carotene (beta -car) compared with astaxanthin (Ax) and their combination on the performances of white shrimp (Litopenaeus vannamei). Eight experimental diets containing 0, 100, 200, 300, 400, 500 mg/kg beta-car, 200 mg/kg Ax, and the combination of 100 mg/kg Ax with 200 mg/kg beta-car were provided for 56-days. The results indicated that shrimp fed beta-car at 300-400 mg/kg had significantly higher growth performance and survival than the other beta-car supplemented treatments without significant differences from shrimp fed Ax(200) and the combination. The redness (a*) of shrimp increased as the beta-car level increased up to 300 mg/kg diet. Furthermore, shrimp fed carotenoid combinational diet developed the deepest red color, consistent with the highest shell Ax contents. Hepatopancreatic total antioxidant capacity (T -AOC) and malondialdehyde (MDA) content showed significantly better performance in shrimp fed carotenoids including diets than the control. Significantly positive relationships were detected on alkaline phosphatase (AKP) activities and dietary beta-car levels. The combination treatment recorded the significantly highest lysozyme activity. Broken-line analysis indicated that the optimal dietary beta-car levels ranged from 265.2 to 341.28 mg/kg diet. In conclusion, data suggested that dietary beta-car could provide an alternative to Ax referring to its efficiency in improving the overall performance of L. vannamei.