Comparison effect of dietary astaxanthin and β-carotene in the presence and absence of cholesterol supplementation on growth performance, antioxidant capacity and gene expression of Penaeus monodon under normoxia and hypoxia condition

Two trials were conducted to determine the effects of two different carotenoid sources on shrimp, Penaeus monodon, first on growth performance, secondly on the immune response of shrimp was investigated with an air emersion challenge. In trial 1, P. monodon (mean initial wet weight about 2.07g) were fed five diets in triplicate; a basal diet (D1) without carotenoids; two diets formulated to supply 0.1% astaxanthin alone (D2), combination of 0.1% astaxanthin and 1% cholesterol (D3); two diets with 0.25% beta -carotene alone (D4), combination of 0.25% beta -carotene and 1% cholesterol (D5). Growth performance (final body weight, FBW; weight gain, WG; biomass gain, BG) and survival of shrimp fed D3 showed the highest values. The apparent digestibility coefficients (ADCs) of carotenoids in carotenoid-supplemented diets (D2-D5) were quietly high (>90%), and cholesterol supplementation did not significantly improve the carotenoid ADCs any more. However, cholesterol addition significantly enhanced the tissue carotenoid retention efficiencies in astaxanthin-supplemented diet treatments (D3 vs D2) but not in beta -carotene-supplemented diet treatments (D5 vs D4). Hepatopancreas malondialdehyde (MDA) and hemolymph clotting time of shrimp fed carotenoid-supplemented diets (D2-D5) were lower (P