The highest PRE ratio was recorded for fish fed diets containing 4.3%
CGL. Protein content of tilapia carcasses increasedwith the inclusion of glycerin in diets P b 0.05). Glycerol can favor protein deposition in the carcass by sparing glucogenicamino acids since glycerol inhibits the ac- tivity of glutamate dehydrogenase activity, as documented by Steele