Unit 3: Incubation, Hatching and Brooding Management of Poultry

1. Incubation

Definition: Incubation is the process of providing the necessary environmental conditions (temperature, humidity, turning, and ventilation) to allow a fertile egg to develop into a chick.

Types of Incubation

1. Natural Incubation:
   • Uses a "broody" hen to sit on and hatch eggs.
   • Suitable only for small-scale/backyard poultry farming.
   • Capacity: A hen can cover 10–15 eggs.
2. Artificial Incubation:
   • Uses mechanical equipment (incubators) to mimic natural conditions.
   • Essential for commercial production.
   • Capacity: Ranges from a few dozen to thousands of eggs.

Selection of Hatching Eggs

To ensure high hatchability and chick quality, eggs must meet specific criteria:

• Fertility: Eggs must be fertile (requires a correct rooster-to-hen ratio in the breeder flock, typically 1:10).
• Weight: Medium-sized eggs are ideal (52g – 60g for chickens). Extremely large or small eggs have lower hatchability.
• Shape: Typical oval shape. Misshapen eggs often do not hatch well due to poor air cell positioning.
• Shell Quality: Strong, smooth shell without cracks. Porous or thin-shelled eggs allow excessive moisture loss.
• Cleanliness: Eggs should be clean but generally not washed (washing removes the protective cuticle). Dirty eggs are sources of bacterial contamination.

Storage of Hatching Eggs

• Temperature: 10°C – 15°C (50°F – 60°F). This arrests embryonic development without killing the embryo.
• Humidity: 75% – 80% Relative Humidity (RH) to prevent dehydration.
• Orientation: Store with the broad end up (air cell up).
• Duration: Ideally less than 7 days. Hatchability declines significantly after 7 days of storage.

Physical Requirements for Incubation (The "Big Four")

The incubation period for chicken eggs is 21 days.

Candling

A process of shining a strong light through the egg to observe development.

• 1st Candling (Day 7): To remove infertile eggs ("clears") and early dead embryos.
• 2nd Candling (Day 18): To remove "dead-in-shell" embryos before transferring to the hatcher.

2. Hatching Management

The incubation process is divided into two distinct phases managed in separate machines or compartments: the Setter and the Hatcher.

Phase 1: The Setter (Day 1 to Day 18)

• Eggs are placed in tilting trays.
• Turning mechanisms are active.
• Temperature and humidity are kept at standard incubation levels.

Phase 2: The Hatcher (Day 19 to Day 21)

• Transfer: On the 18th day, eggs are moved from the setter to the hatcher.
• Turning: Stops completely. The chick must position itself for "pipping" (breaking the shell).
• Temperature: Slightly lowered (approx. 37.2°C / 99°F) to accommodate the metabolic heat produced by the chicks.
• Humidity: Increased (75%+) to soften the shell membranes, making it easier for the chick to break out.

Post-Hatch Management (Hatchery Operations)

1. Sexing: Determining the gender of the chick (vent sexing or feather sexing) to separate pullets (females) for layer farms and cockerels (males).
2. Grading: Removing weak, deformed, or unhealed navel chicks. Only healthy, active chicks are selected.
3. Vaccination: Day-old chicks are often vaccinated against Marek’s Disease (using HVT vaccine) at the hatchery.
4. Packing: Chicks are packed in ventilated boxes (usually 100 per box) for transport.

3. Brooding Management

Definition: Brooding is the art and science of rearing chicks from day-old up to 4–8 weeks of age, during which they require supplemental heat because their thermoregulatory system is not fully developed.

Classification of Brooding

• Natural Brooding: Depending on a broody hen.
• Artificial Brooding: Using temperature-controlled systems.

Types of Artificial Brooders

1. Hover Brooders: An electric heating element with a canopy/reflector.
2. Gas Brooders: Uses LPG; common in areas with unreliable electricity.
3. Infra-red Bulb Brooders: Self-reflecting bulbs; no canopy needed.
4. Battery Brooders: Multi-tiered cages with built-in heating; saves space and minimizes disease (coccidiosis).

Preparation for Brooding

• Cleaning: The house must be cleaned, washed, and disinfected 2 weeks prior to arrival.
• Litter: Spread clean, dry litter (rice husk, wood shavings) to a depth of 2–3 inches.
• Chick Guards: Cardboard or metal circles (12–18 inches high) placed around the brooder to prevent chicks from straying too far from the heat source and to prevent drafts.

Management Practices

1. Temperature Control

The behavior of the chicks is the best thermometer.

• Schedule: Start at 35°C (95°F) in the first week. Reduce by 2.8°C (5°F) every week until room temperature (21°C/70°F) is reached.
• Chick Behavior indicators:
  • Comfortable: Evenly spread under the brooder.
  • Too Cold: Huddled together directly under the heat source; chirping distressfully.
  • Too Hot: Moved far away from the heat source; panting; wings drooping.
  • Drafty: Huddled in one specific corner away from the draft.

2. Feeding and Watering

• Water: Must be provided before feed (with electrolytes/glucose/vitamins) to prevent dehydration. Water should be at room temperature (not cold).
• Feed: Maize grit or pre-starter crumbs provided on paper sheets or flat trays for the first few days to encourage pecking.

3. Space Requirements

• Floor Space: 7–10 sq. inches per chick (0–4 weeks).
• Feeder Space: 2 inches per bird.
• Waterer Space: 0.5 inches per bird.

4. Management of Growers

Definition: Growers are birds aged between 9 weeks and 20 weeks (the period between brooding and sexual maturity/egg laying).

Objectives

• To achieve the target body weight for the breed.
• To achieve sexual maturity at the correct age (not too early).
• To lower mortality.

Housing and Space

• Growers are usually moved from brooder houses to grower houses.
• Floor Space: Increases to 1.5 – 2.0 sq. ft. per bird (deep litter system).
• Litter Management: Stir litter regularly to prevent caking and wetness (which leads to Coccidiosis and Ammonia burns).

Feeding Management: Restricted Feeding

This is the most critical aspect of grower management. If birds eat ad-libitum (freely), they become obese. Fat birds lay fewer eggs and are prone to prolapse.

Methods of Restricted Feeding:

1. Quantitative Restriction: Providing a calculated amount of feed daily (less than appetite).
2. Skip-a-day Feeding: Feeding adequate amounts one day and skipping the next (mostly used in broiler breeders).
3. Qualitative Restriction: Providing low-protein or high-fiber diets.

Benefits:

• Delays sexual maturity (prevents small, early eggs).
• Reduces feed cost.
• Increases longevity of laying.

Other Management Practices

• Beak Trimming (Debeaking): usually done partially at day-old, but precision trimming is often done around 12–14 weeks to prevent cannibalism, feather pecking, and feed wastage.
• Deworming: Carried out periodically (every 6–8 weeks) based on litter examination.
• Vaccination: Critical boosters for Newcastle Disease (Ranikhet) and Fowl Pox must be administered during this phase.

5. Management of Layers

Definition: Layers are birds from the onset of egg production (21 weeks) until the end of the laying cycle (72–80 weeks).

Housing Systems

1. Deep Litter System: Birds on floor. Requires nest boxes (1 box per 5 birds) to ensure clean eggs.
2. Battery Cage System: Most common for commercial layers.
   • Advantages: Higher stocking density, cleaner eggs, no coccidiosis, easier culling, lower feed wastage.
   • Disadvantages: Welfare concerns (lack of movement), cage layer fatigue.

Lighting Management (Photo-stimulation)

Light stimulates the anterior pituitary gland to release FSH and LH, which control ovulation.

• Rule: Never decrease light duration during the laying period.
• Duration: Layers require 16–17 hours of total light (natural daylight + artificial light) per day.
• Intensity: 0.5 to 1 foot-candle. (Dimmer than brooding).

Feeding Layers

• Calcium: Requirements increase drastically for eggshell formation. Layer mash contains 3.5% – 4.0% Calcium (compared to 1% in growers).
• Phase Feeding: Adjusting protein and energy levels based on the age of the bird and production percentage (Phase I: Peak lay; Phase II: Mid lay; Phase III: End lay).

Egg Production Cycle

1. Point of Lay: Approx. 18–20 weeks.
2. Peak Production: Reached at 26–30 weeks (90%+ production).
3. Persistency: The ability to maintain high production.
4. Decline: Production gradually drops. By 72 weeks, production may drop to 65–70%, rendering the flock economically unviable.

Culling (Removal of Unproductive Birds)

Regular culling saves feed costs.

Summer Management for Layers

Layers are highly susceptible to heat stress (no sweat glands).

• Diet: Increase nutrient density (birds eat less in heat), supplement Vitamin C and electrolytes.
• Water: Cool water is crucial.
• Environment: Foggers/sprinklers on the roof, whitewashing the roof to reflect heat.