In the present study, we evaluated the growth performance of grass carp (Ctenopharyngodon idella) and tilapia (Oreochromis niloticus) feeding German grass (Holcus mollis) produced organically using vermicompost. There were three treatments in the experiment, only German grass (T1), German grass + vermicompost @ 8,000 kg ha-1 year-1 (T2) and German grass + vermicompost @ 16,000 kg ha-1 year-1 (T3). In treatment T2 and T3, 25 % vermicompost was applied prior to 15 days ahead of fish stocking. The fish was stocked @ 10,000 grass carps and 15,000 tilapia ha-1, respectively. Water quality parameter such as temperature, dissolved oxygen, pH, nitrite, nitrate, and phosphate were varied among the treatments. 29 phytoplankton and 9 zooplankton genera observed in the three treatments with a significant abundance (p < 0.05) in vermicompost treated ponds. According to a gut content study, tilapia primarily fed zooplankton and phytoplankton, whereas grass carp pre-dominantly consumed German grass and phytoplankton. The gross production was significantly higher in treatment T3 (2.94 Ton ha-1) followed by T2 (2.78 Ton ha-1) and T1 (2.57 Ton ha-1) 77 days-1. The research disclosed that the vermicompost application at 16,000 kg/ha/year with German grass was better option of producing organic grass carp and tilapia.
Key words: German grass, Grass carp, Organic-farming, Tilapia, Vermicompost
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