Title: Dietary zinc requirement of juvenile large yellow croaker,Pseudosciaena crocea
Abstract: A growth experiment was conducted to determine the dietary zinc requirement for juvenile large yellow croaker [initial average weight(1.78±0.02) g].Six semi-purified diets were formulated to contain 9.68,30.63,48.94,91.28,167.49 and 326.81 mg zinc per kg diet,supplied as ZnSO4·H2O.Each diet was randomly assigned to triplicate groups of fish in flowthrough system,and each tank was stocked with 40 juvenile fish.Fish were fed twice daily(05:30 and 17:30) to apparent satiation for 8 weeks.The water temperature fluctuated from 26.5 to 29.5 ℃,salinity from 25 to 28 and dissolved oxygen was approximately 7 mg·L-1 during the experimental period.No significant differences in survival were found among dietary treatments.Specific growth rate(SGR) significantly increased with increasing dietary zinc from 9.7 to 48.9 mg·kg-1 of diet(P0.05),and then leveled off.Zinc content in the vertebrae,whole body and serum was significantly affected by dietary zinc level(P0.05).No significant difference was observed in body protein(14.0%-15.0%),lipid(5.4%-6.1%),ash(3.7%-4.1%) and moisture(76.1%-77.9%) among dietary treatment(P0.05).Broken-line analysis showed that the optimum dietary zinc requirement for large yellow croaker juveniles,using SGR and vertebrae zinc saturation as response criteria,was 59.6 and 84.6 mg zinc per kg diet,respectively.
Publication Year: 2008
Publication Date: 2008-01-01
Language: en
Type: article
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Cited By Count: 7
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