Egg Quality Deffects: Types, Causes and Occurrence: a Review

Poultry egg quality defects are broadly classified as external or internal. About 10% of the total eggs produced are downgraded due to external defects while 1% is due to internal defects. External defects include shell quality, cleanliness, shape, texture and soundness. Egg quality defects lower the grade, consumer appeal, storage/shelf life, hatchability, increase egg breakage and cost of packaging. Internal quality defects are in the yolk and albumen. They occur in the form of blood and meat spots, double yolks, mottled and discoloured yolks, rotten eggs, watery whites, discoloured whites and round worms in eggs. About 5-7% of eggs produced do not reach the consumer; 2-3% of the damage is due to problems during laying and 3-4% during the process after laying. No single factor is usually responsible for egg quality deffects. Factors related to egg quality defects include nutrition, health, flock management, environmental conditions and breeding. It is therefore important for the egg value chain players to understand the various types of egg defects and their causes. This will enable them device ways and means to minimize them, hence improve egg quality.