Eggshell temperature during early and late incubation affects embryo and hatchling development in broiler chicks

Area of Science:

• Animal Science
• Poultry Science
• Embryology

Background:

• Eggshell temperature (EST) is a critical factor influencing embryonic development in poultry.
• Optimizing incubation conditions is essential for broiler chick quality and performance.

Purpose of the Study:

• To investigate the impact of elevated eggshell temperature (EST) during specific incubation periods on broiler embryo and hatchling development.
• To determine the differential effects of early versus late high EST on skeletal development, hatchability, and overall chick quality.

Main Methods:

• A total of 720 broiler eggs were divided into three groups: control, early high EST (days 4-7), and late high EST (days 15-21).
• Measurements included embryonic skeletal development (femur, tibia, metatarsus length and characteristics), hatchability, embryonic mortality, navel score, chick weight, organ weights, tibia ash, calcium, phosphorus, and blood ALP levels.

Main Results:

• Early high EST reduced femur, tibia, and metatarsus length and characteristics at day 18 and hatch, along with tibia ash, calcium, and phosphorus concentrations.
• Late high EST decreased hatchability, increased late-term embryonic mortality, and resulted in higher navel scores and lower chick weight and organ weights at hatch.
• Blood alkaline phosphatase (ALP) and phosphorus levels were higher in the control group compared to both high EST treatments.

Conclusions:

• Early high EST primarily impairs skeletal development in broiler embryos.
• Late high EST negatively affects hatchability and overall hatchling quality, including navel healing and body weight.
• Incubation temperature management is crucial, with distinct critical periods influencing different aspects of broiler development.