Hatching Eggs Lecture Notes

Lecture Three: Hatching Eggs

Intended Learning Outcomes

• Describe the management of a hatchery.

• Identify key performance parameters of a hatchery.

• List optimal performance targets.

Overview of Egg Production

• Breeding Pyramid:

  • Hierarchical structure of poultry breeding.

  • Stages include: Grandparent -> Parent -> Broiler or Layer.

Egg Formation Process

• Light Stimulation:

  • Initiated through the pineal gland in response to light.

  • Triggers the release of Follicle Stimulating Hormone (FSH).

• Follicles and Yolk Production:

  • The ovary produces follicles which contain yolk.

Five Stages of Egg Formation in the Reproductive Tract

• Stage 1: Infundibulum

  • Captures the yolk produced in the ovary.

• Stage 2: Magnum

  • Fertilization occurs here.

• Stage 3: Ismuth (Ismac)

  • Formation of the egg membrane.

• Stage 4: Uterus

  • Eggshell deposition happens here.

• Stage 5: Vagina

  • Egg release occurs; there is no deposition of nutrients here.

Egg Anatomy and Shell Integrity

• Eggshell Characteristics:

  • The shell contains pores for gas exchange.

  • Purpose of Pores: Allow oxygen in for embryo respiration and carbon dioxide out.

• Importance of Shell Integrity:

  • Compromised shells can lead to bacterial entry.

  • Dirty eggs should not be taken to the hatchery due to risks of contamination.

Egg Handling Practices

• Egg Collection:

  • Proper egg handling reduces contamination.

  • Use of egg boxes is vital to prevent egg dirtiness by falling on the ground.

• Management Issues:

  • Exposure of eggs to dirt can lead to compromised shell integrity.

Disinfection of Eggs

• First Step in Hatchery Management:

  • Disinfection occurs after egg collection.

• Common Disinfectants:

  • Formaldehyde (banned due to carcinogenic properties).

  • Alternatives include Hydrogen Peroxide, Quaternary Ammonium Compounds, Ammonia, and Chlorine.

• Characteristics of a Good Disinfectant:

  • Does not compromise cuticle integrity.

  • Bacterial count after treatment should be low.

  • Should not negatively affect hatchability.

Egg Storage and Transport

• Timing for Incubation:

  • Ideal to transfer freshly laid eggs to the hatchery on the same day.

  • Eggs can be stored for a maximum of seven days; hatchability decreases by approximately 1% to 1.5% for each day extended.

• Temperature Regulation:

  • Eggs should be warmed gradually to prevent thermal shock upon entering the incubator (ideal temperature range: 37 to 38°C).

Incubation Process

• Incubation Duration for Chickens:

  • Total of 21 days (18 days in the incubator and 3 days in the hatcher).

• Key Parameters to Monitor:

  • Temperature, humidity, ventilation, and microbial factors.

• Egg Turning:

  • Mimics natural behavior to enhance embryo development.

Candling and Assessment

• Purpose of Candling:

  • Used to determine the fertilization status of the egg and assess embryo health.

  • Typically performed on days 7, 10, and at transfer to the hatcher.

Hatchery Characteristics

• Incubator vs Hatcher:

  • Incubator maintains turning of eggs while hatcher does not.

  • Must provide controlled environments for optimal embryo development.

Vaccination Practices

• In Ovo Vaccination:

  • Vaccination occurs through a needle that punctures the eggshell and injects a vaccine, closing the puncture afterward.

• Types of Vaccines Administered:

  • Respiratory diseases: New Castle disease, Infectious Bronchitis (administered via spray).

  • Vector diseases: Marek's Disease (subcutaneous injection).

Characteristics of Healthy Chicks

• Desirable Traits:

  • Normal, active, and uniform appearance.

  • Absorption of the yolk sac is essential for nutrient uptake.

• Common Problems:

  • Pasty vent (sticky fecal matter) indicating possible health issues.

Hatchery Traffic and Biosecurity

• Unidirectional Flow:

  • Employees must adhere to a one-way flow policy to prevent contamination between areas of the hatchery.

• Hatchery Regulations:

  • Ensures a safe and efficient environment for egg handling and chick processing.