Effect of dietary vitamin E on reproductive performance and vitellogenin gene expression in broodstock of Litopenaeus vannamei

Vitamin E (VE) is one of the most important micronutrients that influence the performance of shrimp reproduction. The effects of different dietary VE levels (0, 100, 300 and 500 mg kg-1) were investigated on the reproductive performance and vitellogenin (Vg) gene expression in Litopenaeus vannamei females which were co-fed with fresh food (two times daily) or experimental diets (two times daily) for 30 days. Sampling was carried out at the first day of the trial, prior to eyestalk ablation (ESA) (day 21) and after ESA (day 30). The reproductive parameters including hepatopancreatic index, absolute fecundity, egg diameter, latency period, and Vg gene expression were higher in the shrimp fed with VE supplemented diets than the control group (p <0.05). After ESA, the Vg gene expression significantly increased in all groups (p <0.05). As a measure of reproductive status of Pacific white shrimp, the present study evaluated correlations of Vg gene expression in hepatopancreas with the number and diameter of oocytes in gonads. Accordingly, Vg is a precursor of vitellin, which is the major yolk protein accumulated in ooplasm. These results provide evidence that dietary VE with 300 mg kg-1 may present a novel strategy and play a positive impact on reproductive performance and Vg gene expression of female shrimp.