IMPROVEMENT OF FISH PRODUCTION AND WATER QUALITY IN TILAPIA CULTURED PONDS BY USING DIFFERENT TYPES OF ARTIFICIAL DIETS AND ORGANIC FERTILIZERS

Document Type : Original Article

Authors

National Institute of Oceanography and Fisheries, Cairo

Abstract

Feeding trials were conducted to evaluate the fluences of the supplementary diets and organic fertilizers on fish production and water quality in tilapia cultured ponds. Tilapia species (Oreochromis niloticus) fingerlings with an initial weight ranged from 16.36 to 16.79 gm was reared in earthen ponds (3 feddans each) at a rate of 6300 fish/fed. (1.5 fish/m²) during a period of 214 days. The cultured fish were fed on three artificial diets (25.0-30.0% protein) composed of different feed ingredients. Ponds 2,3 were fertilized with two levels (low, high) of organic fertilizers (manure). The experiment indicated that, the daily weight gain reached its highest value (1.69 gm/fish) in pond I (fed only on diet 1) and total fish production was 2.209 tons/feddan (5.256 tons /hectar) for fish fed on the same diet. These values slightly decreased to 0.77 gm/fish/day and 2.370 tons in-/ha in pond 3 (fed on diets 3 with high level of fertilization). Meanwhile the profit index has its maximum value (2.00%) for fish reared in pond 2 (fed diet 2 with low level of fertilization). Food conversion ratio has the values of 2.11, 2.25 and 2.42 at the three treatments respectively. With respect to fish body composition, the maximum value of crude protein (70.21%) was observed in fish fed diet 1, ether extract was not affected in the three treatments. While ash content and dry matter reached its highest values (26.95% and 29.66%) in fish of pond 3. In case of water quality, it was noticed that the water temperature, pH value and salinity throughout the rearing period increased gradually from pond 1 to pond 3 in which these values are 31.9°C, 8.6 and 11.8 ppt., while the dissolved oxygen has its maximum value (9.2 mg/L) in pond 1 (feeding only without fertilization).

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