Effect of eggshell temperature throughout incubation on broiler hatchling leg bone development

Area of Science:

• Animal Science
• Poultry Science
• Developmental Biology

Background:

• Leg problems in broiler chickens are a significant welfare concern.
• Eggshell temperature (EST) during incubation influences embryonic development and skeletal formation.
• Understanding the impact of EST on bone development is crucial for preventing leg abnormalities.

Purpose of the Study:

• To investigate the effect of different eggshell temperatures (EST) on the development and asymmetry of broiler chicken leg bones (femur, tibia, metatarsus).
• To assess the impact of EST on hatchability, chick quality, and organ development.

Main Methods:

• Broiler eggs were incubated at four different eggshell temperatures: low (36.9°C), normal (37.8°C), high (38.6°C), and very high (39.4°C).
• At hatch, chick quality parameters (length, body mass, navel score, organ weights) were measured.
• Leg bones were weighed, measured for dimensions (length, width, depth), and ash content was determined. Relative asymmetry was assessed.

Main Results:

• Very high EST significantly reduced hatchability, chick quality, and organ development compared to other temperatures.
• Very high EST led to decreased tibia and metatarsus length, and reduced metatarsus weight and femur length compared to high EST.
• No significant differences in relative asymmetry or bone ash content were observed among the temperature treatments.

Conclusions:

• Very high eggshell temperature during incubation impairs broiler chick development and leg bone formation.
• Optimal eggshell temperature management is essential for improving broiler welfare and skeletal health.
• Low, normal, and high EST showed minimal differences in bone development and chick quality, suggesting a critical threshold for negative effects.