Reproductive Output of Rainbow Trout, Oncorhynchus mykiss (Walbaum), Fed Increasing Levels of Ascorbic Acid

Gavriilidou; G. Fotis; C. Batzios

Reproductive Output of Rainbow Trout, Oncorhynchus mykiss (Walbaum), Fed Increasing Levels of Ascorbic Acid

2003

Gavriilidou | G. Fotis | C. Batzios

Possible effects of increasing dietary levels of ascorbic acid (AsA) on rainbow trout Oncorhynchus mykiss (Walbaum) reproductive parameters such as fecundity, egg diameter, hatchability, embryo and sac-fry mortality, as well as the percentage of the total fry produced, were analysed. A total of four hundred rainbow trout broodstock were equally divided into four groups; four diets (AsA-0, AsA-600, AsA-1200, AsA-2400), one for each group, were fed to fish for a period of 144 days. No additional AsA was incorporated in diet AsA-0, whereas diets AsA-600, AsA-1200 and AsA-2400 were supplemented with AsA to contain 600, 1200 and 2400 mg kg G <SUP>1</SUP>, respectively. From the statistical analysis and evaluation of the research results it was established that the above-mentioned quantities of AsA in the broodstock diet did not cause a significant difference to fecundity or the mean diameter of the eggs (P>0.05). On the contrary, AsA supplementation significantly affects hatchability, sac-fry mortality and the percentage of the total fry produced (P # 0.01). It could be suggested that the addition of 1200 mg AsA kg G <SUP>1</SUP> into rainbow trout broodstock diet increases not only hatchability, but the viability of sac-fry and the percentage of the total fry produced, as well.

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