Feed utilization and wastage in semi-intensive pond culture of mahseer, Tor putitora. (Ham.)

摘要

Mahseer, Tor putitora with 12.75, 12.11, and 12.02g of initial weight were fou · J to attain a net weight gain of 12.0 kg, ll.5 kg, and 11.4 kg respectively in pond-1 (commercial feed), pond-2 (farm-made feed), and pond-3 (farm-made feed), respectively against 78.2 kg, 70.3 kg, and 68.1 kg feed fed. Gross energy contents in fish were 1359.3 Kcal/kg,ud1281.5 Kcal/kg and 1266.6 Kcal/kg, respectively in pond-1, pond-2, and pond-3 againstud3630.4, 3876.9 and 3570.5 Kcal/kg energy in the feed fed. Only 9.4%, 10.5% and 13.7% ofudthe protein, and 8.9%, 3.4% and 3.3% of the lipid fed to fish were converted into muscleudrespectively in pond-1, pond-2 and pond-3. It was observed that the higher the proteinudcontent in feed, the lower the rate of conversion in muscle; the same was also true forudlipid. It is supposed that feed derived wastes contribute potentially to water qualityuddeterioration and eutrophication. Lower feed conversion, higher nitrogenous andudphosphatic concentrations and higher plankton biomass in the ponds are all supportiveudto this observation.