Effect of varying levels of dietary vitamin C (ascorbic acid) on growth, survival and hematology of juvenile tilapia, Oreochromis karongae (Trewavas 1941) reared in aquaria

Authors

  • A. R. Nsonga Department of Aquaculture and Fisheries Science, University of Malawi
  • J. Kang'ombe Department of Aquaculture and Fisheries Science, University of Malawi
  • W. Mfitilodze Department of Aquaculture and Fisheries Science, University of Malawi
  • C. K. Soko Department of Aquaculture and Fisheries Science, University of Malawi
  • A. H. Mtethiwa Department of Aquaculture and Fisheries Science, University of Malawi

DOI:

https://doi.org/10.14210/bjast.v13n2.p17-23

Abstract

Vitamin C (ascorbic acid) requirement of juvenile Oreochromis karongae was studied by incorporating varying levels of ascorbyl-2-polyphosphate in a 40% crude protein diet to obtain 0, 20, 40, 60 and 80 mg ascorbic acid equivalent kg-1 diet. Juvenile fish of 3.7g ± 0.02g initial body weight were used for the study. After 84 days of the experiment, the fish fed AA- supplemented diets had significantly (P < 0.05) higher specific growth rate protein conversion efficiency and protein efficiency ratio; and significantly (P < 0.05) better feed conversion ratios than non supplemented fish. Fish fed non supplemented diet recorded a 33 % rate of mortality, where as those fed with a diet supplemented with 60 mg ascorbic acid kg-1 had mortality as low as 4.4 %. Hematological indices showed a significant increase (P < 0.05) with dietary AA level. Diet containing 60 mg kg-1 of AA showed the maximum growth performance, while the broken line model gave 51 mg ascorbic acid kg-1 diet as the optimal level required by juvenile O. karongae. Our data show that ascorbic acid is essential for O. karongae growth performance.

Author Biographies

A. R. Nsonga, Department of Aquaculture and Fisheries Science, University of Malawi

D

J. Kang'ombe, Department of Aquaculture and Fisheries Science, University of Malawi

Department of Aquaculture and Fisheries Science, University of Malawi, Bunda College of Agriculture, P.O BOX 219, Lilongwe, Malawi.

W. Mfitilodze, Department of Aquaculture and Fisheries Science, University of Malawi

Department of Aquaculture and Fisheries Science, University of Malawi, Bunda College of Agriculture, P.O BOX 219, Lilongwe, Malawi.

C. K. Soko, Department of Aquaculture and Fisheries Science, University of Malawi

Department of Aquaculture and Fisheries Science, University of Malawi, Bunda College of Agriculture, P.O BOX 219, Lilongwe, Malawi.

A. H. Mtethiwa, Department of Aquaculture and Fisheries Science, University of Malawi

Department of Aquaculture and Fisheries Science, University of Malawi, Bunda College of Agriculture, P.O BOX 219, Lilongwe, Malawi.

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Published

2009-12-20

Issue

Vol. 13 No. 2 (2009)

Section

Research Articles

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