WWW.WAS.ORG • WORLD AQUACULTURE • MARCH 2015 45 Center, Prey Veng, Cambodia phannacambodia@yahoo.com Kevin Fitzsimmons, University of Arizona, 1140E. South Campus Drive, Forbes 306, Tucson, AZ 85719 U.S.A. Madhav K. Shrestha, Agriculture and Forestry University (AFU), Chitwan, Nepal, madhavshrestha1954@gmail.com James S. Diana, University of Michigan, Ann Arbor, Michigan, USA Acknowledgments We acknowledge the contribution of collaborators, including Charles C. Ngugi (Kenyatta University, Nairobi, Kenya), Josiah Ani and Henry Lubanga (Department of Fisheries and Aquatic Sciences, University of Eldoret, Kenya), Nam So (Inland Fisheries Research and Development Institute, Phnom Penh, Cambodia), Ramana Oem (Prek Leap National College of Agriculture, Phnom Penh, Cambodia), Nelson Pokhrel and Narayan P. Pandit (Agriculture and Forestry University, Chitwan, Nepal). We acknowledge institutional collaborators the University of Arizona, University of Michigan, University of ConnecticutAvery Point and University of Eldoret, Agriculture and Forestry University (Chitwan, Nepal), Freshwater Aquaculture Research and Development Center (Prey Veng, Cambodia), Inland Fisheries Research and Development Institute (Phnom Penh, Cambodia), which provided facilities and resources. The AquaFish CRSP provided financial support. References APHA (American Public Health Association), AWWA (The American Water Works Association) and WEF (The Water Environment Federation) (2012). Standard Methods for the Examination of Water and Wastewater, 22nd edition. APHA, Washington, DC. Bolivar, R.B., E.B. J. Jimenez and C.L. Brown, 2006. Alternateday feeding strategy for Nile tilapia grow out in the Philippines: marginal cost-revenue analysis. North American Journal of Aquaculture 68:192-197. (CONTINUED ON PAGE 46) TABLE 2. Performance of Nile tilapia in each treatment in Nepal. Parameter Treatment Fertilization only Fertilization with half feeding Full feeding Total stock number 150 150 150 Average stock weight (g/fish) 6.2 ± 0.1 6.3 ± 0.0 6.1 ± 0.1 Total harvest number 42 ± 11 65 ± 8 53 ± 2 Average harvest weight (g/fish) 246 ± 98 343 ± 64 249 ± 26 Daily growth rate (g/fish) 2.0 ± 0.8 2.8 ± 0.5 2.0 ± 0.2 Extrapolated annual production (t/ha) 1.7 ± 0.2 4.3 ± 0.4 2.6 ± 0.2 Production cost (NR/kg) 125 ± 10 9 5± 5 15 0± 13 TABLE 1. Mean (±SD) values of water quality in feed only, fertilizer only and feed plus fertilizer ponds in Kenya and Nepal. Parameter Feed Fertilizer Fertilizer and feed Kenya Nepal Kenya Nepal Kenya Nepal pH 7.8 ± 0.5 7.8 7.8 ± 0.3 8.1 7.7 ± 0.4 6.9 Chlorophyll a (mg/L) 0.01 ± 0.01 0.03 ± 0.01 0.03 ± 0.01 Conductivity (μS/cm) 359 ± 28 278 ± 25 311 ± 25 TDS (NTU) 247 ± 31 185 ± 16 205 ± 16 Total Nitrogen (mg/L) 0.9 ± 0.1 1.2 ± 0.2 1.2 ± 0.1 1.3 ± 0.3 1.1 ± 0.1 0.9 ± 0.2 Nitrite-nitrogen (mg/L) 0.09 ± 0.01 0.04 ± 0.01 0.03 ± 0.00 Total Phosphorus (mg/L) 0.70 ± 0.07 1.5 ± 0.1 0.84 ± 0.06 1.3 ± 0.1 0.85 ± 0.04 0.9 ± 0.3 SRP (mg/L) 0.6 ± 0.001 0.6 ± 0.001 0.2 ± 0.001 DO (mg/L) 5.9 ± 0.3 5.4 ± 0.5 5.4 ± 0.2 4.5 ± 0.7 5.5 ± 0.33 4.3 ± 0.2 Temperature (C) 23.6 ± 0.7 26.3 ± 0.01 23.2 ± 0.5 26.5 ± 0.01 22.8 ± 0.4 26.4 ± 0.2 Ammonia (mg/L) 0.07 ± 0.06 0.8 ± 0.0 0.07 ± 0.06 0.5 ± 0.0 0.05 ± 0.04 0.5 ± 0.1 Alkalinity (mg/L) 291 ± 89 115 ± 4 329 ± 67 156 ± 22 274 ± 81 162 ± 21 CO2 (mg/L) 57 ± 34 81 ± 46 33 ± 15 Hardness (ppm) 55 ± 13 60 ± 14 49 ± 5 Secchi disk depth (cm) 26.0 ± 1.6 27.5 ± 0.4 27.7 ± 0.5
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