Abstract

In aquaculture, feed accounts for more than half of the input cost. The biofloc technology (BFT) helps manage nitrogenous waste and produce floc-proteins. Focusing this, we investigated the effect of feed reduction on the growth, survival and digestive function of Labeo gonius fry in BFT. The experiment includes two feeding levels (3% and 6%) in BFT and a clearwater system (control). Advanced fry (mean weight = 0.94 g) were randomly distributed into four groups: 3% BFT, 6% BFT, 3% CN and 6% CN and fed 35% protein diet for 60 days. In BFT, molasses was used as carbon source and a carbon to nitrogen ratio of 20:1 was maintained. Growth was comparable in 6% CN and 3% BFT (p>0.05); however, highest in 6% BFT. Survival percentage was non-significant (p>0.05). Feed conversion ratio improved significantly (p<0.05) in biofloc group, compared to control, coinciding with higher activity of protease and amylase enzymes. Overall, biofloc system at both level of feeding delivers better growth and digestive enzyme activity. However, considering a comparable growth in 3% biofloc and 6% control, we concluded that restriction in feeding level (50%) is possible for early seed rearing of L. gonius in BFT. This work unravels the idea of feed minimization for better profit margin.

Singh, S.K., Debbarma, R., 2024. Reduced feeding strategy during fry rearing of Kuria Labeo (Labeo gonius) in biofloc system: Effects on growth and digestive enzyme activity. Research Biotica, 2024, online first.