Effects of Different Preparations Containing Selenium on Selenium Status and Reproductive Performance of Common Carp ( <i>Cyprinus carpio L</i> .) Broodstock

Abstract This study evaluated the efficiency of different Selenium supplements on blood Se status and reproductive performance of carp broodstock. Female carp (n=120) were distributed in 4 groups supplemented with Se as follows: control (non-supplemented), sodium selenite 200 µg/kg feed, sodium selenite i/m injection (160 µgSe/kg bodyweight), and selenized yeast 200 µg/kg feed. Blood was sampled on days 1, 20, and 30. On day 30, samples of roe were taken from females, and samples of blood and milt from 10 unsupplemented males. Larvae samples were taken after hatching. Plasmatic Se concentration was 51.38±3.77 µg/kg (day 1) and did not vary significantly. The erythrocyte Se concentration increased from 14.04±3.05 µg/kg (day 1), reaching 90.58±12.43 (day 20), to 212.38±57.87 µg/kg (day 30). Plasmatic glutathione peroxidase activity in supplemented groups increased from 4.41±1.15 to 7.73±2.26 μkat/L and plateaued until day 30. A similar pattern was observed for erythrocyte glutathione peroxidase activity, ranging from 54.51±15.45 μkat/L (day 1) to 80.72± 6.82 μkat/L (day 30). Se concentration and selenoenzyme activities in males did not differ from the female control group. Roe Se content ranged from 48.26±17.53 μg/L in control to 65.68±34.39 μg/L in fish supplemented selenized yeast, and in the pooled larvae samples, ranged from 26-43 μg/L. The Se concentration in the milt was 24.78±4.27 μg/L. Results suggest that 250 µgSe/kg feed was sufficient to meet the requirements of mature carp, sodium selenite being more efficient in elevating blood Se concentrations and selenoenzymes activities, while selenized yeast being more efficient in roe and larvae.