In recent years, different strategies have been implemented to optimize the activity and make it intensive and sustainable, so biofloc technology (BFT) has been implemented in production, reducing the volume of daily water replacement and providing complementary food to organisms during culture. In addition to biofloc, strategies for efficient use of food in aquaculture have begun to be developed, such as intermittent feeding and compensatory growth, especially in detritus-consuming species, a technology that to date has not been evaluated in the Malayan prawn (Macrobrachium rosenbergii) in conjunction with biofloc culture. Therefore, the objective was to evaluate the effect of food restriction on the survival, growth and enzyme activity of Malayan prawn (M. rosenbergii) postlarvae during their culture in biofloc.
The experimental design was completely randomized with six treatments and three replicates. Three treatment were kept in clear water (W) and three in biofloc (B) with 3 days restriction / 3 days refeeding (3) and 3 days restriction / 6 days refeeding (6). Controls (BC) and (CW) received food daily. 15 prawns of 0.5 g were used and the study lasted 75 days. The parameters of water quality, productive performance, as well as proximal composition and digestive enzyme activity in hepatopancreas and intestine were evaluated. Data were analyzed with an ANOVA and Tukey test at p<0.05. The physicochemical variables in water were within the tolerance range for the PL´s. The survival at the end of the study was similar in the treatments and greater than 80%. The most efficient growth was obtained in BC, which was significantly higher than the rest of the treatments. Partial compensatory growth of treatments B3 and B6 was observed vs BC and total compensatory growth was obtained when compared B3 and B6 vs clear water control (WC), indicating that the biofloc allows maintaining the growth of the organisms even in the absence of commercial food. (Table 1). The nutritional composition of the prawns subjected to the treatment BC is significantly higher compared to the other treatments. Variations in enzymatic activity were observed in the hepatopancreas and in the intestine as a response to adapt to changes in food restriction and use of the biofloc.