Effect of Different Application Rates of Cowdung and Poultry Excreta on Water Quality and Growth of Ornamental Carp, Cyprinus carpio vr. koi, in Concrete Tanks

Larvae (0.09±0.025 g) of Koi carp (Cyprinus carpio vr. koi) were cultured in outdoor concrete tanks for 90 days. Individual weight gain and survival rates were compared among a control (C), three treatments manured every 10 days with cowdung, applied at 0.13 kg/m3 (C1), 0.26 kg/m3 (C2), and 0.39 kg/m3 (C3), and three treatments manured every 10 days with poultry excreta, applied at 0.13 kg/m3 (P1), 0.26 kg/m3 (P2), and 0.39 kg/m3 (P3). Weight gain of Koi carp stocked at P2 was significantly higher than other treatments. There was a significant difference in survival of Koi carp among the treatments, ranging from 65.5% to 86% in C and P2, respectively. The C3 and P3 treatments yielded significantly higher values of specific conductivity, NH4 - N, NO2 - N, and PO4 - P, and significantly lower values of dissolved oxygen than the other treatments. Zoobenthos population was low in all the treatments. The results suggest that application rate of 0.26 kg/m3 every 10 days seems to be the most suitable for Koi carp tanks manured with both cowdung (C2) and poultry excreta (P2), through maintenance of better water quality and greater abundance of plankton in the system. Suitable environment in C2 and P2 resulted in significantly better growth of Koi carp than other treatments.
Anahtar Kelimeler:

Koi carp, Cyprinus carpio vr

Effect of Different Application Rates of Cowdung and Poultry Excreta on Water Quality and Growth of Ornamental Carp, Cyprinus carpio vr. koi, in Concrete Tanks

Larvae (0.09±0.025 g) of Koi carp (Cyprinus carpio vr. koi) were cultured in outdoor concrete tanks for 90 days. Individual weight gain and survival rates were compared among a control (C), three treatments manured every 10 days with cowdung, applied at 0.13 kg/m3 (C1), 0.26 kg/m3 (C2), and 0.39 kg/m3 (C3), and three treatments manured every 10 days with poultry excreta, applied at 0.13 kg/m3 (P1), 0.26 kg/m3 (P2), and 0.39 kg/m3 (P3). Weight gain of Koi carp stocked at P2 was significantly higher than other treatments. There was a significant difference in survival of Koi carp among the treatments, ranging from 65.5% to 86% in C and P2, respectively. The C3 and P3 treatments yielded significantly higher values of specific conductivity, NH4 - N, NO2 - N, and PO4 - P, and significantly lower values of dissolved oxygen than the other treatments. Zoobenthos population was low in all the treatments. The results suggest that application rate of 0.26 kg/m3 every 10 days seems to be the most suitable for Koi carp tanks manured with both cowdung (C2) and poultry excreta (P2), through maintenance of better water quality and greater abundance of plankton in the system. Suitable environment in C2 and P2 resulted in significantly better growth of Koi carp than other treatments.