Ahmed T.
Department of Fisheries, University of Dhaka, Dhaka-1000, Bangladesh.
Faruque M.H.
Department of Fisheries, University of Dhaka, Dhaka-1000, Bangladesh.
Kabir M.A.
Department of Fisheries, University of Dhaka, Dhaka-1000, Bangladesh.
Mustafa M.G.
Department of Fisheries, University of Dhaka, Dhaka-1000, Bangladesh.
Stocking density, Labeo bata, Earthen pond, Yield, Cost-benefit analysis
Maa Fish Farm, Nawabgonj, Dinajpur, Bangladesh
Animal Health and Management
Performance
This on-farm study was carried out in six private rearing ponds of „Maa Fish Farm” Nawabgonj, Dinajpur, Bangladesh for a period of 60 days from August to October 2015. The surface area of each pond was 2 decimals with average water depth of 1 meter. The ponds were rectangular in shape, also had similar basin conformation, contour and bottom type. Fish fry were stocked at a rate of 750 fry decimal-1, 1000 fry decimal-1 and 1250 fry decimal-1 designated as treatment-1 (T1), treatment-2 (T2) and treatment-3 (T3), respectively, each with two replicates. The mean initial weight and sizes of fry were 1.02±0.06g and 3.42±0.07 cm, respectively. Prior to stocking, preparation of rearing ponds were done according to the practice followed by Chakraborty et al. (2007) and Samad et al. (2014). Then, all ponds were stocked with L. bata fry which was collected from Fish Seed Multiplication Farm, Parbatipur, Dinajpur, Bangladesh. After stocking, all the ponds were fertilized with both organic and inorganic fertilizer recommended by (DOF, 2011) at weekly intervals to stimulate the primary productivity of the ponds. Nursery feed (Aftab feed) was given to stocked fish at the rate of 10, 8, 6 and 5% for the fish attaining 1-3, >3-7, >7- 10 and >10 g body weight, respectively. Fish were manually fed twice a day at 9 am and 4 pm with two equal splits of the ration. The feed was broadcast on the pond water surface. Proximate composition of the feed was analyzed according to AOAC (2012) method in the Nutrition Laboratory of the Department of Fisheries, University of Dhaka. Crude protein, crude lipid, crude fiber, ash and moisture of the experimental feed was 31.80%, 6.74%, 8.25%, 15.84%, and 11.12%, respectively. Water quality parameters of the experimental ponds were monitored at 7 days interval between 9 am and 11 am. Portable digital thermometer (TFA Germany, D-97877 Wertheim) was used to record water temperature (?C). Dissolved oxygen (DO), pH and transparency (cm) were measured using DO meter (HACH, HQ30d), pH meter (HACH, sensIONTM PH31) and Secchi disk, respectively. Alkalinity testing kit (HACH, AL-AP) was used to measure the total alkalinity of water samples. Thirty (n=30) individuals from each pond were sampled by a fine-meshed nursery net at 15 days interval throughout the experimental period for the assessment of growth and for feed adjustment. At the end of trial, all fish were harvested and survival rate (%), finals weight and length, production (number ha-1 and kg ha-1), specific growth rate (SGR=ln final weight−ln initial weight/days×100,%/day), feed conversion rate (FCR, weight of feed/gain in wet weight of fish) of each pond and treatment were calculated. The data were analyzed through one- way analysis of variance (ANOVA) followed by Tukey test for post hoc comparisons. All data were expressed as mean±SD. Estimation of the net benefits from different treatments was simply done by cost-benefit analysis.
Iranian Journal of Fisheries Science; Volume- 18(4) 771-778; 2019
Journal