Day 21 Management: Transitioning to Finisher Feed & Ventilation Control
Critical Day 21 management principles for broiler farms including target weight parameters, feed phase adaptation, vaccine audits, and ventilation balance.
Day 21 Management: Transitioning to Finisher Feed & Ventilation Control
By Day 21 (Week 3), your broiler flock is entering a critical rapid-growth phase. Over the next seven days, feed consumption will multiply. This makes the next phase highly susceptible to respiratory diseases and metabolic disorders if ventilation and gut health are not maintained.
1. Weekly Performance Indicators
Compare your batch to standard growth targets:
| Parameter | Cobb 500 Target | Ross 308 Target | Ideal Range |
|---|---|---|---|
| Cumulative Feed Consumed | 1,280g / bird | 1,320g / bird | 1,250g - 1,350g |
| Average Body Weight (ABW) | 980g | 1,020g | 950g - 1,050g |
| FCR Target | 1.30 | 1.29 | 1.28 - 1.33 |
| Cumulative Mortality | < 1.0% | < 1.0% | 0.0% - 1.2% |
2. Dynamic Calculators
Calculate your actual flock metrics in real-time below.
Feed Conversion Ratio (FCR) Calculator
Interactive ComponentBatch Mortality Rate Calculator
Interactive Component3. Feeding & Water Management
Transition the flock from Grower Feed to Finisher Feed. This process must be completed gradually over 48 hours to avoid causing structural stress to the birds' digestive systems.
Gradual Transition Protocol
Checklists for Feed & Water
4. Ventilation & Litter Management
With increased feed and water intake, the volume of manure excreted grows exponentially. Ammonia control is the primary objective of Day 21 management.
Ammonia Spike Hazard
Bio-Monitoring & Health Observations
Maintain high visual standards in the house.
{ "indicator": "Even spread of birds" } Birds are spaced evenly throughout the house. This indicates optimal temperature distribution and proper draft ventilation.
{ "indicator": "Clear, bright eyes and high alertness" } Flock responds immediately when you make sounds or enter the pen, signifying clean air and zero respiratory congestion.
5. Frequently Asked Questions
Why is my FCR spiking above 1.50 at Day 21?
Usually, this indicates feed waste caused by feeders placed too low, or intestinal damage caused by sub-clinical coccidiosis. Verify your litter is dry and calculate FCR regularly.
6. Key References
- Cobb 500 Broiler Management Guide (2025)
- Indian Council of Agricultural Research (ICAR) Poultry Handbook