EFFICACY OF A LYSINE-TRYPTOPHAN BLEND FOR GROWTH OF PIGLETS

An experiment was conducted to compare the growth-promoting efficacy o f a new source of L-tryptophan and L-lysine, Tryptosine(R) (15 % L-try ptophan, 56 % L-lysine) with pigs in the body weight range 10-25 kg fo r the L-tryptophan portion. A tryptophan deficient corn-pea-barley bas al diet was used, containing 0.16 % total tryptophan corresponding wit h 0.11 % apparent ileal digestible tryptophan. Two graded doses of try ptophan (0.03 and 0.06 %) of either tryptophan from Tryptosine or L-tr yptophan were added to the basal diet. Each diet was fed to two pens w ith each 10 castrated male pigs and two pens with each 10 female pigs. The trial consisted of a pre-test period of 15 days and an experiment al period of 28 days during which period the experimental diets were f ed. Results indicated a clear tryptophan deficiency of the basal diet. Graded doses of tryptophan to the basal diet resulted in improvements in weight gain, daily feed intake and feed conversion rate. The diffe rences in weight gain and feed conversion rate between both tryptophan sources were not significant. From the results of the study it was co ncluded that the biological activity of tryptophan from Tryptosine(R) is equal to that of L-tryptophan in piglets.