title: Estimation of lysine requirements of growing Japanese quail during the fourth and fifth weeks of age.
abstract: A dose-response assay was conducted using broken-line regressions to estimate the lysine (Lys) requirements of quail chicks from 21 to 35 d of age. A basal diet was formulated to be adequate in all nutrients other than Lys. Incremental levels of L-Lys.HCl were added to the basal diet at the expense of a mix of cornstarch, NaHCO3, and NaCl to create 6 experimental diets containing 0.84 to 1.59% Lys. Feed intake (FI), weight gain (WG), and feed conversion ratio (FCR) responded quadratically to incremental levels of Lys (P < 0.0001). Using the linear broken-line (LBL) model, the estimated Lys requirements for WG during the fourth and fifth wk of age were 1.25 and 1.23% of diet, respectively. The corresponding values for FCR were estimated at 1.23 and 1.26% of diet, respectively. Fitting the quadratic broken-line (QBL) model, the estimated Lys requirements for WG during the fourth and fifth wk of age were 1.34 and 1.34% of diet, respectively. The corresponding values for FCR were estimated at 1.35 and 1.36% of diet, respectively. This study showed that using the QBL model as a promising way to estimate amino acids needed in the diet, the optimal Lys level to optimize performance of growing Japanese quail at the late stage of production might be 1.36% of diet, which is 105% of NRC recommendations.
authors.affiliation: Department of Animal Sciences, College of Agriculture, University of Zabol, Zabol, 98661-5538 Iran mehri@uoz.ac.ir.
authors.forename: Mehran
authors.initials: M
authors.lastname: Mehri
authors.affiliation: Department of Animal Sciences, College of Agriculture, University of Zabol, Zabol, 98661-5538 Iran.
authors.forename: Farzad
authors.initials: F
authors.lastname: Bagherzadeh Kasmani
authors.affiliation: Department of Animal Sciences, College of Agriculture, University of Zabol, Zabol, 98661-5538 Iran.
authors.forename: Morteza
authors.initials: M
authors.lastname: Asghari-Moghadam
mesh_terms: D000375:Aging / Q000502:physiology*; D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D003370:Coturnix / Q000254:growth & development*; D004032:Diet / Q000662:veterinary*; D004305:Dose-Response Relationship, Drug; D008239:Lysine / Q000378:metabolism*; D009751:Nutritional Requirements
chemical_list: D008239:Lysine
keywords: Japanese quail; broken-line model; lysine requirement; performance