title: The cysteine, total sulfur amino acid, tyrosine, phenylalanine + tyrosine, and non-essential amino acid maintenance requirements of broiler breeders.
abstract: Two hundred and fifty Cobb-Vantress broiler breeders were used to determine the maintenance requirement and efficiency of utilization of dietary Cys, Tyr, and non-essential amino acids (AA) in a 21-day experiment. The breeders were fed crystalline amino acid diets containing graded levels of Cys or Tyr representing 0, 10, 20, 30, and 40% of their suggested requirement level with all other amino acids maintained at 40% of their suggested requirement level. To determine the non-essential AA maintenance requirement, graded levels of non-essential AA were provided by glutamic acid to represent 12, 19, 26, 33, and 40% of the ideal level of glutamic acid with all other amino acids maintained at their maintenance requirement level. The total sulfur amino acid (TSAA) and Phe + Tyr requirements were calculated by combining Cys and Tyr results, respectively, with previously determined Met and Phe, respectively. The slope of Cys, Tyr, and non-essential AA accretion regression line indicated that 29% Cys, 24% TSAA, 21% Tyr, 20% Phe + Tyr, and 9% non-essential AA of crystalline amino acids were retained. The Cys requirement for zero protein accretion was calculated to be 30.48 mg/d or 17.006 mg/ kgBW(0.75)/d or 75.426 mg/kgCP/d. The TSAA requirement for zero accretion was calculated to be 132.25 mg/b/d, 71.48 mg/kgBW(0.75)/d, and 307.55 mg/kgCP/d. The Tyr requirement for zero protein accretion was calculated to be 65.907 mg/d or 37.233 mg/ kgBW(0.75)/d or 175.566 mg/kgCP/d. The Phe + Tyr requirement for zero protein accretion was calculated to be 352.18 mg/b/d, 190.37 mg/kgBW(0.75)/d, and 749.33 mg/kgCP/d. The non-essential AA requirement for zero protein accretion was calculated to be 3715.194 mg/d or 2003.155 mg/kgBW(0.75)/d or 9452.954 mg/kgCP/d.
authors.affiliation: University of Arkansas, Center of Excellence for Poultry Science, Fayetteville, Arkansas 72701.
authors.forename: R D
authors.initials: RD
authors.lastname: Ekmay
authors.affiliation: University of Arkansas, Center of Excellence for Poultry Science, Fayetteville, Arkansas 72701.
authors.forename: S J
authors.initials: SJ
authors.lastname: Mei
authors.affiliation: University of Arkansas, Center of Excellence for Poultry Science, Fayetteville, Arkansas 72701.
authors.forename: N K
authors.initials: NK
authors.lastname: Sakomura
authors.affiliation: University of Arkansas, Center of Excellence for Poultry Science, Fayetteville, Arkansas 72701 ccoon@uark.edu.
authors.forename: C N
authors.initials: CN
authors.lastname: Coon
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000603:Amino Acids, Sulfur / Q000378:metabolism; D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects; D000818:Animals; D002645:Chickens / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism; D004032:Diet / Q000662:veterinary; D005260:Female; D009751:Nutritional Requirements; D010649:Phenylalanine / Q000378:metabolism; D011897:Random Allocation; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000596:Amino Acids; D000603:Amino Acids, Sulfur; D014443:Tyrosine; D010649:Phenylalanine; D003545:Cysteine
keywords: Phe + Tyr; TSAA; broiler breeders; maintenance; non-essential amino acids