Poultry Nutrition Encyclopedia
Biochemical guidelines, amino acid digestibility, and mineral balancing metrics.
Scientific Overview
Feed comprises 60-70% of commercial poultry production costs. Formulating diets requires balancing metabolizable energy (AMEn), digestible amino acids (lysine, methionine, threonine), and minerals (calcium and phosphorus) to support skeletal growth, feathering, and egg shell calcification.
Amino Acid Digestibility & Ideal Protein Profile
Chickens do not have crude protein requirements; they require specific digestible amino acids. The Ideal Protein Profile measures amino acid requirements relative to digestible Lysine (set at 100%). digestible Methionine + Cystine should be balanced at 74% of Lysine for broilers, and Threonine at 65%.
Calcium & Phosphorus (Ca:P) Balance
Calcium and Phosphorus must be balanced to support skeletal health and prevent leg disorders. For growing broilers, maintain the Ca:P ratio between 2.0:1 and 2.2:1. Excess calcium binds phosphorus in the gut, forming insoluble calcium phosphate complexes that cause rickets. Layer hens require high calcium (3.8 - 4.5% of total feed, formulated in our interactive Feed Formulation Calculator) to support eggshell calcification in the uterus.
All scientific data, diagnostic criteria, and performance benchmarks presented on this page are derived from published peer-reviewed journals and official veterinary codes:
- Avian Pathology & Diagnostics: World Organisation for Animal Health (WOAH, 2023). Manual of Diagnostic Tests and Vaccines for Terrestrial Animals. Paris, France.
- Poultry Diseases & Histology: Swayne, D.E., et al. (2020). Diseases of Poultry (14th ed.). Wiley-Blackwell / American Association of Avian Pathologists.
- Nutrition & Feed Chemistry: Leeson, S. & Summers, J.D. (2001). Commercial Poultry Nutrition (3rd ed.). University Books, Guelph, Ontario.
- Commercial Breed Standards: Aviagen (2024). Ross 308 & Cobb 500 Broiler Performance Objectives. / Lohmann Breeders (2024). Lohmann Brown Management Guide.