Abstract
A feeding experiment was conducted to evaluate the effect of non-supplementation of individual vitamins A, E, and C on the ovarian development of P. japonicus (mean weight =20.21±0.87g). Vitamin A palmitate, DL-α-tocopherol, and L-ascorbyl-2-phosphate magnesium (APM) were used as the vitamin A, E, and C sources, respectively. A control diet was supplemented with these three vitamins. Bilateral eyestalk ablation was performed within 30-37 days after feeding with the experimental diets, and weight gain and gonado-somatic index (GSI) were examined 20 days after each prawn's ablation.
The weight gain of prawns fed with the control diet was significantly higher (P<0.05) than of those fed with diets not supplemented with vitamins A or E; however, this was no different (P>0.05) from that of prawns fed with the APM-unsupplemented diet. The highest GSI (P<0.05) was observed in prawns fed with the control diet. The control and initial prawn tissues contained higher vitamins A, E, and C than those of prawns fed with diets unsupplemented with vitamins A, E, or APM respectively. The present study showed the essentiality of supplemental vitamins A, E, and C in the diets of broodstock prawns for enhanced ovarian development.
