Comparative Analysis of the Benefits of Glutathione-Rich Yeast Hydrolysate and Astaxanthin on Growth Performance, Antioxidant Capacity and Lipid Metabolism in Pacific White Shrimp (Litopenaeus vannamei).

Antioxidants, both glutathione (GSH) and astaxanthin (AX), possess beneficial applications in animal growth and antioxidant properties. In this study, three experimental diets with isoproteic and isolipidic were formulated, the control diet (CON), the control diet added with 0.03% Carophyll Pink (contains 10% AX), the control diet added with 0.67% glutathione-rich yeast hydrolysate (GYH, contains 5% GSH). The effects of AX and GYH on the growth performance, antioxidant capacity and lipid metabolism of Litopenaeus vannamei (0.36 ± 0.01 g) were compared. After an 8-week feeding experiment, shrimp growth and intestinal morphology showed significantly better performance in the GYH group. Both dietary AX and GYH regulated the expression levels of genes related to lipid metabolism, increased antioxidant enzyme activities and total antioxidant capacity of shrimp and reduced haemolymph malondialdehyde and hepatopancreas reactive oxygen species production. Compared with the CON and GYH groups, dietary AX significantly increased the redness (a*) and yellowness (b*) values of cooked shrimp. Based on the evaluation of the above results, AX and GYH were comparable in terms of antioxidant performance, and AX was superior in improving the red body colour of shrimp, but GYH has more significant advantages in promoting shrimp growth and intestinal development. Therefore, supplementation with GYH or AX in diet presents specific benefits to the growth, body colour and antioxidant of L. vannamei.