Comparative juvenile performance assessment of genetically improved Nile tilapia ( Oreochromis niloticus L.) under commercial conditions in Bangladesh

Two experiments were conducted consecutively to evaluate and compare the mean weight (MWT), daily growth rate (DGR), feed conversion ratio (FCR), survival and production rate (PR) in the non-improved strain (NS) of the Nile tilapia, Oreochromis niloticus (Cichlidae) with those in the Genetically Improved Farmed Tilapia (GIFT) strain and the FaST selected tilapia (FaST), from the swim-up fry stage to fish weight of 1.0 g (Experiment 1) and from fish weight of 1.0 to 20 g (Experiment 2). In both experiments, results showed the GIFT and FaST strains to have significantly higher MWT, faster DGR, lower FCR and higher PR than those of the NS. Unlike in Experiment 1, survival rates did not differ significantly among the three strains. In Experiment 1, the improvements in the FaST for the MWT, DGR and PR over those for the NS were 77.9, 72.9 and 33.6%, respectively. In Experiment 2, the improvements for the same parameters were 58.7, 57.8 and 54.5%, respectively. These results indicate the advantage and potential of culturing the FaST or the GIFT strain in Kuwait for improving the production of fresh tilapia, reducing the production cost and increasing the profitability of tilapia farms.

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Growth Performance of GMT and Mixed Sex Nile Tilapia Oreochromis niloticus on Natural and Supplemental Feeds

Asian Fisheries Science ◽

10.33997/j.afs.2007.20.4.008 ◽

2007 ◽

Vol 20 (4) ◽

Author(s):

P.W. PERSCHBACHER

Keyword(s):

Oreochromis Niloticus ◽

Nile Tilapia ◽

Food Sources ◽

Natural Food ◽

Ictalurus Furcatus ◽

Recirculating Aquaculture System ◽

Recirculating Aquaculture ◽

Aquaculture System ◽

Nile Tilapia Oreochromis Niloticus ◽

Genetically Improved

Attention has been focused on genetically-improved stocks and strains of tilapia. A greenhouse recirculating aquaculture system (RAS) of three 540 L tanks stocked with 100 37.2 g genetically male tilapia (GMT) Nile tilapia, Oreochromis niloticus, and three identical tanks with the same number of 38.1 g mixed sex Nile tilapia, was used to measure response to floating 3.0 mm catfish pellets (32 % protein) fed once per day at four different rates based on body weight day-1 (2-4 % BW day-1). Feed rate and amount were changed every 14 days based on growth measurements. For growth comparisons on natural feeds (primarily phytoplankton), two 10.5 m3 net pens were each stocked in August with 105 7.7 g Nile tilapia m-3 of each group in each of two 1.0 ha blue catfish Ictalurus furcatus fingerling ponds and not fed. Fish were harvested in November. GMT fish outperformed mixed sex fish on both feed sources, and at most feed rates. In RAS trials at 2, 2.5, 3.0 and 4.0 % BW feeding, percentage growth day-1 was 1.95, 2.11, 2.21 and 3.31 for GMT, and 1.60, 2.22, 1.97 and 2.86 for mixed sex; and the associated food conversion ratio (FCR) was 1.54, 1.37, 1.37 and 1.04 and 1.64, 1.35, 1.42 and 1.20, respectively. At harvest in net pens, GMT fish were 25 % larger than mixed sex. Growth was 1.3 and 1.0 g day-1 on natural food sources for GMT and mixed sex, respectively.

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