title: Research note: effect of excess lysine, methionine, threonine, or tryptophan on production performance of laying hens.
abstract: An experiment was conducted with laying hens to determine effects of feeding excesses of several individual amino acids in a practical layer diet. Single Comb White Leghorn hens, which were in peak production (31 wk of age), were assigned to one of five dietary treatments: a 16% CP corn and soybean meal positive control diet, or this diet fortified with 1% additional L-Lys, 1% additional DL-Met, 1% additional L-Thr, or 1% additional L-Trp. The diets were fed for ad libitum intake for 4 consecutive wk of production. For the entire production period, hen-day egg production, egg yield, and feed intake were not significantly different among any of the treatments. The study indicated that considerable tolerance exists in high-producing laying hens for individual excesses of the amino acids commonly used as supplements in poultry diets.
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801.
authors.forename: K W
authors.initials: KW
authors.lastname: Koelkebeck
authors.forename: D H
authors.initials: DH
authors.lastname: Baker
authors.forename: Y
authors.initials: Y
authors.lastname: Han
authors.forename: C M
authors.initials: CM
authors.lastname: Parsons
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002645:Chickens / Q000254:growth & development / Q000502:physiology*; D004531:Eggs / Q000592:standards; D005260:Female; D008239:Lysine / Q000008:administration & dosage / Q000494:pharmacology*; D008715:Methionine / Q000008:administration & dosage / Q000494:pharmacology*; D010058:Oviposition / Q000187:drug effects; D011897:Random Allocation; D013912:Threonine / Q000008:administration & dosage / Q000494:pharmacology*; D014364:Tryptophan / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D013912:Threonine; D014364:Tryptophan; D008715:Methionine; D008239:Lysine