Effect of selected levels of dietary protein on the Growth and feed efficiency of mullet Liza macrolepis fry

Abstract

In the experiment conducted in laboratory for a period of 45 days to evaluate the effect of selected dietary protein levels (30%, 35%, 40%, 50%, 60%) on survival, growth, conversion efficiency and protein efficiency ratio in the fry of the mullet Liza macrolepis, using purified diets, the high protein levels 40% to 60% gave better results on survival rate (69% to 87%). Maximum gain in length and relative growth (56.6%) was at 40% protein level. However, low conversion efficiency (2.41 )and high protein efficiency ratio (1.388) were at 30% protein diet. The maximum body proteins in the fish coincided with 35% protein diet and 40% protein diet and the minimum body protein was at 30% protein diet and again at 60% protein diet. Although the minimum conversion efficiency and maximum protein efficiency ratios were observed at 30% protein level, data on survival, growth and body protein content indicate that for the fry of Liza macrolepis the optimum protein level in the diet is 40%.