title: Evaluation of tryptophan requirement of the commercial layer by using a corn-soybean meal basal diet.
abstract: An experiment was conduced with Hy-Line W36 hens to evaluate the requirement for Trp in a corn-soybean meal diet. Seven experimental diets were fed with Trp levels of 0.12, 0.13, 0.14, 0.15, 0.16, 0.17 and 0.18%. Supplemental amino acids (AA) were added to all diets to ensure that Trp was the first-limiting AA. A positive control diet (0.20% Trp) with Met supplementation was fed that had previously been shown to support maximum performance. Egg production (EP), egg weight (EW), and egg content (EC) were significantly increased by the addition of Trp to the basal diet. Broken-line regression indicated the Trp requirement for EP and EC was 139.8 and 149.0 mg per hen/d, respectively, for EP and EC when hens had a daily EC of 45.4 g per hen/d.
authors.affiliation: Department of Dairy and Poultry Science, University of Florida, Gainesville 32611, USA. Harms@dps.ufl.edu
authors.forename: R H
authors.initials: RH
authors.lastname: Harms
authors.forename: G B
authors.initials: GB
authors.lastname: Russell
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000378:metabolism* / Q000502:physiology; D004531:Eggs / Q000032:analysis; D005260:Female; D016014:Linear Models; D009751:Nutritional Requirements; D010058:Oviposition; D013025:Glycine max / Q000378:metabolism; D014364:Tryptophan / Q000378:metabolism* / Q000592:standards; D015430:Weight Gain; D003313:Zea mays / Q000378:metabolism
chemical_list: D014364:Tryptophan