EFFECT OF DIETARY-PROTEIN LEVEL ON APPARENT HEAT INCREMENT AND POSTPRANDIAL NITROGEN-EXCRETION OF PENAEUS-SETIFERUS, PENAEUS-SCHMITTI, PENAEUS-DUORARUM, AND PENAEUS-NOTIALIS POSTLARVAE

The calorigenic effect of feeding (apparent heat increment, AHI) and p ost-prandial nitrogen excretion (PPNE) were measured in postlarval (PL 25-30) Penaeus setiferus, P. schmitti, P. duorarum and P. notialis fe d a fixed ration of 3 mg/animal using purified diets with 40, 50, 60, or 65% protein, Both AHI and PPNE increased with increasing dietary pr otein, The contribution of PPNE to AHI varied from 6.1 to 94%, with le sser values for P. setiferus and greater ones for P. duorarum, Also, t he AHI coefficient (percentage of ingested energy) increased with incr easing dietary protein. The AHI and PPNE coefficients for the four shr imp species ranged from 0.3 to 6.5% and 0.02 to 5.04% of ingested ener gy, respectively, These results suggest close relationships among prot ein requirements, the capacity to use dietary proteins as a source of energy, and adaptation by different species to different types of food , The amount of energy used for production of ammonia is proposed as a n adequate measure of the part played by dietary proteins in food cost .