title: Efficacy of a lysine-tryptophan blend for growth of chicks.
abstract: Two chick experiments were conducted to compare the growth-promoting efficacy as well as the toxicity of a new source of L-tryptophan and L-lysine, Tryptosine (16.1% tryptophan, 56.3% lysine). A corn-feather meal-soybean meal basal diet was made singly deficient in either lysine or tryptophan, and graded doses of lysine or tryptophan from either Tryptosine or feed-grade sources of lysine and tryptophan were supplemented. Linear (P < .01) weight gain responses occurred, and responses to lysine or tryptophan in Tryptosine were similar to those obtained with equal doses of lysine or tryptophan provided by feed-grade sources of L-lysine.HCI or L-tryptophan. The toxicity trial involved additions of 1, 2, or 4% lysine with .29, .58, or 1.16% tryptophan to a lysine- and tryptophan-adequate corn-soybean meal diet. Both amino acids were provided as either Tryptosine or as feed-grade sources of lysine and tryptophan. Weight gain and feed intake were reduced in a linear fashion (P < .01) as levels of the two excess amino acids increased. The decreases caused by Tryptosine were similar to those caused by equivalent levels of excess feed-grade lysine and tryptophan.
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Baker
authors.forename: S R
authors.initials: SR
authors.lastname: Fernandez
authors.forename: H M
authors.initials: HM
authors.lastname: Edwards
authors.forename: C M
authors.initials: CM
authors.lastname: Parsons
mesh_terms: D000818:Animals; D002645:Chickens / Q000254:growth & development* / Q000502:physiology; D004032:Diet / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000502:physiology; D005260:Female; D008239:Lysine / Q000032:analysis / Q000494:pharmacology* / Q000592:standards; D008297:Male; D013025:Glycine max / Q000592:standards; D014364:Tryptophan / Q000032:analysis / Q000494:pharmacology* / Q000592:standards; D015430:Weight Gain / Q000187:drug effects / Q000502:physiology; D003313:Zea mays / Q000592:standards
chemical_list: D014364:Tryptophan; D008239:Lysine