Glutamic acid and tryptophan additions to a low-protein pig starter.

Two feeding trials with baby pigs were conducted to evaluate the effects of additions of L-tryptophan and L-giutamic acid to a low protein (16%) starter diet on performance and plasma urea nitrogen, a-amino nitrogen and free tryptophan. In experiment 1, but not in experiment 2, glutamic acid addition (3.36%) improved rate of gain and feed efficiency. Tryptophan addition did not improve performance in either experiment. Plasma tryptophan data in both experiments indicated that the tryptophan level ~.nd availability were adequate in the low-protein diet. The response to glutamic acid suggests inadequate levels of dispensable amino acids for the baby pig in the low-protein basal diet.