Effect of food restriction on compensatory growth and enzymatic activity of freshwater prawn post larvae (M. rosenbergii), during its culture in Biofloc

Abstract

Abstract During 75 days, the effect of food restriction/cyclic refeeding was evaluated on the survival, growth, and digestive enzymatic activity in hepatopancreas and intestine of post larvae (PL 20) of freshwater prawn cultured with/without biofloc. A completely randomized experimental design was used in triplicate: Three treatments were kept in clear water (C) and three with biofloc (B): C3/B3: 3 days’ restriction / refeeding; C6 / B6: 3 days’ restriction / 6 days’ feedback and their respective controls BC: control with biofloc; C: control with clear water; where the control groups received food daily. The parameters of water quality, the productive performance of the prawns, as well as proximal composition, and digestive enzyme activity in hepatopancreas and intestine were evaluated. The physicochemical variables in water were within the tolerance range for the PL´s. The survival was similar to the treatments and greater than 80%. The most efficient growth was obtained in BC, which was significantly higher than the others treatments, while the growth of the C prawns was similar to B3 and B6, which indicates that the biofloc covered the nutritional needs that allowed compensatory growth despite the temporary absence of commercial feed. Variations in enzymatic activities were observed in the hepatopancreas, where the highest enzymatic activity of the amylase, lipase, acid, and alkaline phosphatase enzymes occurred in the biofloc treatments, these enzymes being indicative of the nutrient absorption processes present in the biofloc during times of restriction of organisms, generating an adaptation advantage during times of food restriction, improving culture conditions.