Observation on some of the environmental parameters and feed quality of selected golda (Macrobrachium rosenbergii) farms in Bangladesh

摘要

A study was conducted to ascertain the existing farm water, effluent and feed quality of selected giant freshwater prawn farms from major prawn farming areas (Bagerhat Sadar, Noakhali Sadar and Mymensingh) of Bangladesh during July to November 2005. Water quality parameters such as the mean values of dissolved O_2, alkalinity, NO_2-N, PO_4-P and NH_3-N did not show any significantly differences among the farming areas. Whereas significant differences (p<0.05) were observed in the mean values of temperature, secchi disc visibility, pH and chlorophyll a. However, all the water quality parameters in the farming areas were within the suitable range for prawn culture. There was no significant variation in nutrients concentration of discharged effluent among the prawn farming areas. All of the nutrients measured in effluent water were within the acceptable range and did not seem to pose a direct threat to the recipient environment. The analysed crude protein contents of commercial CP, Quality and Saudi-Bangla prawn feeds were 31.84%, 27.21% and 28.97%, respectively, whereas all analysed farm made feeds were less than 25%. The other nutrients of prawn feeds varied largely with the source of feeds and ingredients used to prepare feed. The annual yield ofprawn varied from 320.4 to 512.6 kg ha~(-1) (mean 412.3 kg/ha) depending on the management system.