title: Dietary threonine response of Pekin ducks from hatch to 14 d of age based on performance, serology, and intestinal mucin secretion.
abstract: Two experiments were conducted to determine the dietary threonine (Thr) requirement of Pekin ducks from hatch to 14 d of age. In experiment 1, practical corn-soybean meal diets were formulated to contain 0.78, 0.84, 0.90, 0.96, and 1.02% Thr (0.74, 0.83, 0.88, 0.92, and 1.00% Thr on an analyzed basis). In experiment 2, corn-soybean meal diets supplemented with 11 crystalline amino acids were formulated to contain 0.60, 0.70, 0.80, 0.90, 1.00, and 1.10% Thr (0.60, 0.75, 0.89, 0.95, 1.01, and 1.09% Thr on an analyzed basis). In both experiments, diets were fed to 8 replicate cages with 6 male ducks per cage. Body weight and feed intake from each cage were recorded weekly. At 14 d of age, breast meat, ileal digesta, and serum were collected to determine breast meat yield, mucin secretion, and serology parameters. In both studies, the estimated Thr requirement (expressed as % dietary Thr basis) for 14 d BW and BW gain (BWG) by quadratic broken-line (QBL) regression were similar, which were 0.87 and 0.86%, respectively. Additional measures in both experiments resulted in Thr requirements via QBL regression in rank order of crude mucin secretion < breast meat yield < serum immune activity. Summing up the estimates from both studies, the Thr requirement ranged from a low of 0.81% to maximize feed intake (FI) to a high of 1.00% to maximize serum Rb L100 by QBL regression. Correspondingly, the Thr requirement varied between a low of 0.90% to maximize crude mucin secretion on a dry matter intake (DMI) basis and a high of 0.98% to maximize feed-to-gain when using quadratic regression.
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, IN 47907.
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 Institute of Animal Nutrition, Sichuan Agricultural University, Ya'an, Sichuan Province, 625014, PR China.
authors.forename: Q F
authors.initials: QF
authors.lastname: Zeng
authors.affiliation: Cotter Laboratory, Arlington, MA 02476.
authors.forename: P
authors.initials: P
authors.lastname: Cotter
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 applegt@uga.edu.
authors.forename: T J
authors.initials: TJ
authors.lastname: Applegate
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects; D000818:Animals; D030161:Avian Proteins / Q000235:genetics / Q000378:metabolism*; D001823:Body Composition / Q000187:drug effects; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D004063:Digestion / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004372:Ducks / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D005786:Gene Expression Regulation; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D009077:Mucins / Q000235:genetics / Q000378:metabolism*; D009751:Nutritional Requirements; D011897:Random Allocation; D013912:Threonine / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D030161:Avian Proteins; D009077:Mucins; D013912:Threonine
keywords: Pekin duck; growth performance; mucin; serology; threonine