Dietary substitution of protein concentrate of Ulva lactuca for soybean meal in the black tiger shrimp Penaeus monodon fry

A feeding trial was conducted to test the protein concentrate of the green seaweed Ulva lactuca as a substitute for soybean meal in the diet of the black tiger shrimp Penaeus monodon fry. Experimental diets containing various replacement levels for soybean meal by weight were prepared, namely 0 (control diet), 15, 30 or 45% Ulva protein concentrate (UPC). Survival rate was not affected by the diets. Feed intake (FI) was statistically similar in shrimp fed the control diet and diet containing 15% UPC replacement while the FI of shrimps fed diets containing 30% and 45% were lower and were not significantly different from each other. SGR of shrimps fed the control diet was not significantly different from the values of those fed diets containing 15% and 30% UPC replacements while those fed diets containing 45% UPC replacement exhibited significantly the lowest SGR. Protein gained of shrimps were statistically similar between those fed the control diet and those fed diets with 15% and 30% UPC while those fed diets at 45% UPC was significantly lower than the three groups. Protein efficiency ratio (PER) was unaffected by the dietary treatments. Ulva protein concentrate could be a substitute for soybean meal in the diet of Penaeus monodon fry up to 30% without compromising the survival, growth and feed utilization efficiency of the shrimp despite lower feed intake