Abstract
This study evaluates the effect of L-ascorbyl-2-polyphosphate (Vitamin C) on Litopenaeus vannamei immune and antioxidant responses, as well as sperm quality of broodstock males. Four diets were formulated: Basal (control group (16 mg/kg of total Vitamin C), and the other three prepared with different vitamin C levels: A (322 mg/kg); B (628 mg/kg); and C (934 mg/kg). Circulant cholesterol, triglyceride (TG), glucose, and total protein were measured. Activities and differential expressions of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and the immune gene system in the reproductive tract were measured. Sperm quantity and quality were determined. The lowest activity of the antioxidant enzymes was obtained in B (628 mg/kg) and the highest one in C (934 mg/kg) (p ≤ 0.05) diets. The immune system genes only showed differences in hemocyanin where the highest expression was obtained in B (p ≤ 0.05) diet. The highest sperm quantity was determined in individuals fed B (p ≤ 0.05) diet, which supplemented with 628 mg/kg Vitamin C benefit L. vannamei broodstock males because it guarantees less antioxidant system activity, suggesting a good physiological state.
Keywords: Sperm quality, Shrimp, Oxidative stress, Catalase, Glutathione peroxidase.