Growth, survival and production of Macrobrachium rosenbergii (de man) with an indigenous feed

Abstract

Growth, survival and production of the giant freshwater prawn Macrobrachium rosenbergii have been evaluated with an indigenous feed developed at CIFT. The experiment was conducted in a freshwater pond in the Instructional Farm of the College of Fisheries. After initial preparations, prawn post larvae having an initial size of 20mm/7mg were stocked at the rate of 3 nos/m super(2). They were fed with crumble feed at the rate of 20% of the body weight for the first fifteen days. Feeding was reduced to 10% of the body weight for the next one month, then to 5% and finally to 2% during the last month. Observations on water temperature, pH, salinity and dissolved oxygen were made at weekly intervals during the culture period. The prawns were harvested at the end of 175 days and a production of 602.5 kg/ha/175 days was obtained. The gross production in the experiment works out to 830 kg/ha/175 days which includes the prawn and Chanos chanos which were introduced at a low stocking density in the pond for control of algal blooms. The retrieval rate of the prawns was 79.16%. A conversion ratio of 1.86 was obtained for the feed with the cost of the feed working out to only Rs.15/kg, since the feed with 40% protein contained only cheap indigenous animal and plant protein ingredients. The net profit works out to Rs.43,175/ha with the cost benefit ratio of 2.19.