Influence of organic selenium and stocking density on performance of Nile tilapia, Oreochromis niloticus.
2012
Naiel, M.A.E. | Nasr, A.E. | Ahmed, M.H.
ABSTRACT The present study was carried out to investigate the effect of organic ýselenium supplementation and stocking density on growth performance traits, feed ýefficiency, chemical body composition, blood parameters of Nile Tilapia (Oreochromis ýniloticus). Fish (5.5 ± 0.1 g) were randomly distributed in two groups of density (10 and ýý20 fish/aquarium). Each stocking density was divided into three treatments two of which ýwere fed diet (30% crude protein) containing 0.3, 0.6 g OS/kg (T2, T3), whereas the other ýtreatment (TI) was fed a basic diet without OS. The feeding rate was 3% of the live body ýweight. The feed was offered twice daily six days a week for 12 weeks. Fish growth ýindicated as live body weight, weight gain and specific growth rate (SGR) increased ýsignificantly and the maximum growth was obtained when fish fed diet containing 0.6 g ýOS/Kg. The highest feed intake and the lowest feed conversion ratio (FCR) were ýobtained for group of fish fed 0.6 g OS/Kg. Total lipids in fish body decreased ýsignificantly with the increase of organic selenium level in fish diet (p0.05), while crude ýprotein increased significantly by low density and interaction between T2 and low ýdensity. Also, ash content increased significantly with the increase of organic selenium ýlevel in fish diet (p0.05). Moreover, OS supplementation (T3) decreased serum ýcreatinine, uric acid and alanine aminotransferase (ALT) while aspartate ýaminotransferase (AST) not affected. It could be concluded that OS supplementation 0.6g ýOS/Kg enhanced fish growth, feed utilization, body composition and healthy of Nile ýTilapia fish.ý
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