Layer Grower (9-20 Wks)
Layer Grower (9-20 Wks)
Identity
Pullet rearing feeding phase designed to control growth rates before sexual maturity in egg-type birds. Under IS 1374:2024, the late stage of this phase (weeks 17-20) is formalized as a distinct Pre-Lay Feed.
Overview
Layer Grower (9-20 Wks) represents the critical development window prior to the onset of lay. It focuses on promoting digestive tract capacity and maintaining growth without adding excess fat, which could lead to prolapse or erratic laying patterns. The 2024 standard formalized the Pre-Lay Feed segment (weeks 17-20) to preemptively load calcium reserves by elevating calcium levels to 2.0%. This preemptive calcification constructs medullary bone tissue, ensuring the hen does not rapidly deplete structural bones when shell calcification begins.
Structured Facts
Classification
Feeding Phase > Layer; Layer Feeds > Pullet Developmental Rations.
Biological Functions
Regulates sexual maturation, promotes digestive tract capacity, constructs medullary bone tissue, and controls skeletal growth.
Nutritional Requirements
Strictly managed energy and protein to prevent premature egg production and obesity. Minimum metabolizable energy of 2400 kcal/kg and minimum 16.0% crude protein. Requires elevated calcium (2.0%) during the 17-20 week pre-lay window.
Deficiency
- Clinical Signs: Calcium shortfall prior to lay causes cage layer fatigue and osteoporosis.
Toxicity
- Clinical Signs: Excess fat leads to prolapse or erratic laying patterns.
Feed Phase Requirements
- Pre-Starter: Not applicable
- Starter: Not applicable
- Grower: Weeks 9 to 16.
- Finisher: Not applicable
- Breeder: Not applicable
- Layer: Pre-Lay Feed from weeks 17 to 20.
Quantitative Data
- Requirement: Metabolizable Energy, Crude Protein, Calcium, Phosphorus, Lysine, Methionine, Threonine.
- Minimum Level: Metabolizable Energy: 2400 kcal/kg; Crude Protein: 16.0%; Calcium: 1.0% (Grower) / 2.0% (Pre-Lay); Total Phosphorus: 0.65%; Available Phosphorus: 0.40%; Lysine: 0.70%; Methionine: 0.30%; Methionine + Cystine: 0.52%; Threonine: 0.52%.
- Maximum Level: Moisture: 11.0%; Crude Fibre: 9.0%; Acid Insoluble Ash: 4.0%; Salt: 0.5%.
- Unit: Percentage (%) by mass (dry matter basis), kcal/kg.
Relationships
- Related Nutrients: Calcium, Phosphorus, Lysine, Methionine, Threonine.
- Diseases: Cage Layer Fatigue, Osteoporosis, Prolapse.
- Breeds: Egg-Type Layers.
- Production Stages: Weeks 9 to 20.