Evaluation of lysine and methionine supplemented duckweed (Lemna minor) based diet for Labeo calbasu

摘要

An investigation was conducted to evaluate the effect of dietary supplementation of lysine and methionine, on growth performance and nutrient retention of Labeo calbasu fingerlings. Four experimental duckweed based diets AO (control, without lysine or methionine supplementation), Al (lysine), A2 (methionine) and A3 (both lysine and methionine supplementation) were fed to L. calbasu for 90 days in laboratory conditions. All treatments were maintained in replicate of three. Significantly higher (P<0.05) growth and nutrient utilization in terms of weight gain, specific growth rate, protein efficiency ratio, apparent protein digestibility and lower feed conversion ratio were observed in the fingerlings of group A3, fed on diet supplemented with both lysineand methionine. Significantly (P<0.05) low ammonia excretion and reactive phosphate production in holding water by A3 fed group denote the less deamination of protein fed resulting in better water quality. Significantly high erythrocyte and leucocyte count by A3 fed fingerlings illustrated superior health. Although group fed with lysine and methionine supplemented diet separately (diet Al and A2) did not show low growth, carcass composition yet significantly more effective growth and improved protein accumulation was depicted by fish when fed on diet containing both the indispensable amino acids together revealing proper and efficient functioning and utilization of amino acids to balance the protein synthesis. The supplementation of essential amino acids can be helpful in promoting growth and feed utilization of candidate species by preventing halt in the protein synthesis imparted by the use of deficient and low value plant protein source.