Layer Phase I
Layer Phase I
Identity
Primary production feeding phase for egg-type layers characterized by high calcium demand.
Overview
Layer Phase I corresponds to the period from the onset of lay, through peak production (typically exceeding 90% hen-day production), to the stabilization of egg mass. It prioritizes eggshell quality, sustained laying performance, and albumen synthesis by implementing a high concentration of highly bioavailable calcium balanced with available phosphorus. The biological demands on the hen are immense, requiring the synthesis of egg albumen and a calcium carbonate shell approximately every 25 hours.
Structured Facts
Classification
Feeding Phase > Layer; Layer Feeds > Production Laying Rations.
Biological Functions
Sustains peak hen-day egg output, maintains albumen quality, and supports structural shell synthesis.
Nutritional Requirements
High levels of highly bioavailable calcium (3.75% minimum), balanced available phosphorus (0.35%), and a minimum crude protein content of 14.0%.
Deficiency
- Clinical Signs: Cage Fatigue, thin-shelled eggs.
- Economic Impact: Poor eggshell quality.
Toxicity
Bioavailability
Requires highly bioavailable calcium.
Feed Phase Requirements
- Pre-Starter: Not applicable
- Starter: Not applicable
- Grower: Not applicable
- Finisher: Not applicable
- Breeder: Not applicable
- Layer: Weeks 21 to 45.
Quantitative Data
- Requirement: Metabolizable Energy, Crude Protein, Calcium, Phosphorus, Lysine, Methionine, Threonine.
- Minimum Level: Metabolizable Energy: 2400 kcal/kg; Crude Protein: 14.0%; Calcium: 3.75%; Total Phosphorus: 0.65%; Available Phosphorus: 0.35%; Lysine: 0.70%; Methionine: 0.30%; Methionine + Cystine: 0.52%; Threonine: 0.52%.
- Maximum Level: Moisture: 11.0%; Crude Fibre: 10.0%; Acid Insoluble Ash: 4.5%; Salt: 0.5%.
- Unit: Percentage (%) by mass (dry matter basis), kcal/kg.
Relationships
- Related Nutrients: Calcium, Phosphorus, Lysine, Methionine, Threonine.
- Diseases: Cage Fatigue, Thin-shelled Eggs.
- Breeds: Egg-Type Layers.
- Production Stages: Weeks 21 to 45.