Effect of dietary threonine on laying performance and intestinal immunity of laying hens fed low‐crude‐protein diets during the peak production period

• Published in: Journal of animal physiology and animal nutrition 2017-10, Vol.101 (5), p.e55-e66
• Main Authors: Azzam, M. M. M., Dong, X. Y., Zou, X. T.
• Format: Article
• Language: English
• Subjects: a low‐protein diet; Amino acids; Animal Feed - analysis; Animal Nutritional Physiological Phenomena; Animals; Biomedical materials; Chickens - immunology; Chickens - physiology; Constraining; Conversion ratio; Diet; Diet - veterinary; Dietary Proteins - administration & dosage; Dietary supplements; Dose-Response Relationship, Drug; Egg production; Feed conversion; Female; Hogs; Immune response; Immune system; Immunity; Interleukin 1; Interleukin 2; Interleukin 6; intestinal immune function; Intestine; Intestines - drug effects; Intestines - immunology; laying hens; Low protein diet; mRNA; Mucosal immunity; Nutrient deficiency; Oviposition - drug effects; Oviposition - physiology; Poultry; proinflammatory cytokines; Proteins; Surgical implants; Threonine; Threonine - administration & dosage; Threonine - pharmacology; Trypsin; Uric acid
• ISSN: 0931-2439; 1439-0396
• DOI: 10.1111/jpn.12559

Summary Threonine (Thr) may be a limiting amino acid for laying hens fed diets with lowered protein level. An experiment was conducted to examine laying performance, and the intestinal immune function of laying hens provided diets varying in digestible Thr levels. Lohmann Brown laying hens (n = 480), 28 weeks of age, were allocated to six dietary treatments, each of which included five replicates of 16 hens. Dietary crude protein (CP) 16.18% diet was offered as the positive control diet. L‐Thr was added to the negative diet (14.16% CP) by 0, 1.0, 2.0, 3.0 and 4.0 g/kg, corresponding 0.44%, 0.43%, 0.49%, 0.57%, 0.66% and 0.74% digestible Thr. At 40 weeks, a reduction in CP level decreased laying performance (p