A review on yolk sac utilization in poultry

Area of Science:

• Poultry Science
• Embryology
• Animal Nutrition

Background:

• Embryonic development relies on egg nutrients, transferred via yolk stalk or yolk sac membrane.
• Increased broiler metabolic rates may reduce residual yolk reserves, impacting posthatch performance.

Purpose of the Study:

• To assess changes in residual yolk weight and composition over 88 years (1930-2018).
• To identify factors influencing yolk utilization during incubation and posthatch.

Main Methods:

• Systematic review of scientific publications from 1930 to 2018.
• Comparison of residual yolk weight, metabolic heat production, and yolk utilization.

Main Results:

• Residual yolk weight and total solids appear decreased in recent decades.
• Limited effects on yolk utilization efficiency and embryonic heat production despite genetic and management improvements.
• Egg size and incubation temperature significantly affect residual yolk weight; breeder age influences yolk composition.

Conclusions:

• Residual yolk weight has likely decreased, but its impact on efficiency is minimal.
• Abiotic factors like egg size and incubation temperature are crucial for yolk utilization.
• Further research needed to fully understand genetic selection and management impacts on yolk reserves.