Preliminary assessment of herbivory in silver barb, Puntius gonionotus
1990
Gouthaman, Gopalan
Experiment was conducted for a period of 64 days to determine the efficacy of macrophytes (cassava, duckweed, chopped paragrass, rice and water spinach) fed ad libitum to Puntius gonionotus in an unfertilized system. The effect of chopping was tested on cassava and water spinach. Commercial pellet was used as the control. The feed intake/day on a dry weight basis was negatively related to the fibre and positively related to the protein content of the feed. But protein and fibre contents did not fully explain the difference in intake of different feeds. Protein intake (dry weight basis) was positively related to the feed intake (dry weight basis). Growth expressed as weight gain (g), % weight gain, daily weight gain (g) and relative growth rate (g/kg fish/day) showed a positive relationship with protein intake. The lower total digestibility in relation to higher protein digestibility and lack of correlations between growth and food conversion ratio, protein efficiency ratio and protein conversion efficiency showed that most of calculated non-protein energy was unavailable in all feeds except for pellet, hence protein was an important energy source. Duckweed with higher protein was fed more and resulted in better growth. The paragrass and rice with the lowest protein content were fed less and resulted in poor growth. The growth parameters for all other feeds lay in between and overlapped. An experiment on the feeding rate of small fish of size 2.8-4.5 cm showed they were able to feed on water spinach leaves and Lemna. But a growth trial is needed to study the feeding value of these macrophytes for these smaller silver barb.
显示更多 [+] 显示较少 [-]