Effects of Dietary Lysine for River Catfish Juveniles on Protein Digestibility and Body Composition

Abstract

The success of intensive aquaculture for river catfish juveniles (Pangasius hypophthalmus Sauvage, 1878) is determined by the availability of good quality feed. Good quality feed does not only contain protein required by the fish; it should also contain essential amino acids to support fish growth. Lysine is a constraint of amino acids in the formulation diet due to the characteristics of the plant-based protein with lysine deficiency. This study was conducted to determine the dietary effects of lysine river catfish juveniles on protein digestibility, body composition, and relative growth rate. The river catfish juveniles used in the study had a mean weight of 8.21 g ± 0.32 g fishP -1P . The test feed contained 37.1 % and 19.76 MJ kgP -1 P . Doses of lysine in the feed were added in an increase of 0.25 g 100 gP -1 P [1.48 g; 1.73 g; 1.98 g; 2.23 g; 2.48 g, and 2.67 g] 100 gP -1 P dry diet)]. The results showed that a lysine-added diet with the dose of 2.23 % 100 gP -1 P dry diet generated the highest values of protein digestibility (ADCp), relative growth rate (RGR), and fish body composition compared to other treatments. The optimal dose of lysine in feed for protein digestibility and relative growth rate of river catfish juveniles were 2.22 % to 2.24 % dry diet.