Md. Abdus Samad
Dept. of Fisheries, University of Rajshahi, Rajshahi-6205
Md. Yeasir Arafat
Dept. of Fisheries, University of Rajshahi, Rajshahi-6205
Habiba Ferdaushy
Fish inspection and quality control officer, DOF, Dhaka, Bangladesh
Sujit Kumar Chatterjee
Fish inspection and quality control officer, DOF, Dhaka, Bangladesh
Alok Kumar Paul
Dept. of Fisheries, University of Rajshahi, Rajshahi-6205
Md. Mustafizur Rahman
Dept. of Fisheries, University of Rajshahi, Rajshahi-6205
Fingerling, Indigenous, Labeo rohita, Majorcarp, Stocking density
Maherchandi village, Matihar thana, Rajshahi
Animal Health and Management
The experiment was carried out for a period of 60 days from 14th August, 2013 to 14th October, 2013 in the south side of Maherchandi village, Matihar thana, Rajshahi. Experimental design: Experiment was conducted with 3 different treatments of stocking densities of Rui (Labeo rohita) namely T1, T2, T3. Treatments assignment were T1: 400000/ha, T2: 500000/ha and T3: 600000/ha.Pond preparation: Before start of the experiment, to repair dyke and bottom of the study pond, all the aquatic weeds and insects were removed. The quantity of rotenone was used 19.76 kg/ha for the removal of predatory and unwanted fish species. 227.24 kg/ha lime was used for the pond preparation by the farmer. The pond was prepared by using cow dung 1326.39 kg/ha, by using urea 242.06 kg/ha, by using TSP 192.66 kg/ha. Sources of water were deep tube-well and rain. The water was supplied by the pump machine.Collection of fry: Fry were collected from the “Rajshahi Fish Feed Hatchery”, Rajshahi, Bangladesh. Fry were transported to the experimental site through plastic bag with proper aeration. Stocking of fry: Rearing ponds were stocked with the separated fries of Labeo rohita after three weeks nursing for research purposes. The size of the stocked fires was 1.5±0.12 cm length and 0.43±.13 g weight. The length and weight of around 10% of all fry of each pond was measured and recorded for estimating initial stocking biomass and to adjust initial feeding rate for fishes. Feeding of fishes: Fries were fed three same type of supplemental feed for different treatments (T1, T2, and T3), such as fish meal, mustard oil cake, rice bran, wheat flour and maize bran at the rate of 8-10% of body weight daily.The supplemental feed was given to fry at the rate of 10%, 8% in 1st and 2nd month respectively. The quantities of feed were adjusted every 15 days interval on the basis of increase in the average body weight of the stocked biomass. The proximate composition of each, the feed were carried out in accordance with A.O.A.C method (1990). Growth sampling of fish: Fries were sampled from each rearing ponds by using small meshes seine net at fortnightly interval to determine the change in their growth in terms of length and weight gain. At least 10% fish from each pond was taken to make assessment of growth trends and to readjust feeding rate. Length and weight of sampled fish were measured using a measuring scale and digital electric balance (OHAUS, MODEL No.CT-1200-S). Fishes were handled carefully to avoid stress during sampling. Monitoring of water quality parameters: Different water quality parameters such as temperature (ºC), transparency (cm), pH, dissolved oxygen (mg/l), alkalinity, ammonia-nitrogen (mg/l) of the ponds were monitored at 8.00 am in each fortnight to assess the physico-chemical condition of the pond and analyzed by using HACH water quality analytical kit (FF2, USA). Growth parameters: Several parameters (Mean weight gain, Total weight gain, Specific growth rate, and Survival rate) were used to evaluate the growth performance of fishes under different treatments. Growth data collected from different treatments during the trials were calculated and analyzed using following equations: Mean weight gain (g) = Mean final weight (g) -Mean initial weight (g),Total weight gain (g) = Mean weight gain (g) × Number of fish (g), Length gain (cm) = final length (cm) –initial length (cm), SGR (%, bwd-1) = Error!x100 (Brown, 1957: Ricker, 1975), Survival rate (%) = Error!x100 (De Silva, 1989) Production of fish: At the end of the experiment, the ponds were drained and the fishes were enumerated and measured. Production was calculated based on average final weight of the harvested fishes and was expressed as kg/ha. The formula is Production = No. of harvested fishes x final weight of fish.Input cost and profit analysis: Simple cost-benefit analysis was followed to study the economics of fingerling production of Labeo rohita under different treatments for the present study. Data on both fixed and variable costs were recorded to determine the total cost (BDT/ha/60 days). Total return determined from the market price of fish was expressed as BDT/ha/60 days. Net benefit calculated by deducting the total return from total cost was expressed as BDT/ ha/60days.CBR was calculated, CBR=Net benefit/total cost. Statistical analysis: For the analysis of collected data, one-way analysis of variance (ANOVA) was performed by using the SPSS (Statistical Package for Social Science, evaluation version-16.0) program and significance was assigned at the 0.05% level and tested Duncan’s New Multiple Range Test (DMRT) to identify significant differences among the mean values (Zar, 1984).
J. Biosci. Agric. Res. 12(01): 968-975
Journal