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Livestock-Based Farming Systems, Renewable Resources and the Environment |
The aim of the experiment was to study on replacing earthworm by water spinach or duckweed on growing frogs with basal diet of rice bran and broken rice in 18 ponds with area of 2 m2 (2m x 1m) and 0.4m deep in each pond. All ponds were lined with white plastic in order to avoid filtration of water. A total of 144 frogs were bought from farmer and adapted to experimental area and feed for 10-15 days before started experiment. Frog stocking densities were 4 frogs per m2. The experiment design was Completely Randomized Design (CRD) with 3*2 factorial arrangements of 6 treatments and three replications within each treatment, the first factor was protein sources from earthworm (EW) alone, duckweed mix with earthworm (DW-EW) or water spinach mix with earthworm(WS-EW) and second factor was with or without light supplementation at night. In overall, the DM feed offer and CP offer were not different of DW-EW and EW but lowest was found in WS-EW treatment (P<0.001). DM feed offer and CP offer were high when light was supplement rather than without light supplementation. The live weight gain were found the best in all period of experiments when the frogs fed EW diet rather than WS-EW or DW-EW treatment (P<0.05). Supplementing light was effect on live weight gain compared with without light supplementation (P<0.05) but accepted from 30-60 days (P>0.05). The feed conversion ratio in DM basis was better on DW-EW and EW alone and poorest was WS-EW treatment (P<0.001), while the light supplementation was not effect (P>0.05) but excepted period of 60-90 days, feed conversion ratio were better on light supplementation (P<0.05). The survival rate and net yields were highest on earthworm treatment and not different in mixture of DW-EW and WS-EW. Light supplementation was effect on high survival rate and yield compared with without light supplementation. It can concluded that growth rates, survival and yield were best on treatment earthworm alone and light supplementation, while the mixture of duckweed with earthworm were improved but poorest was water spinach mix with earthworm.