Avian Production Management

EGG QUALITY - SPECIFIC GRAVITY

• This gives an indication of the egg shell quality, as well as its freshness. Fresh eggs will have higher specific gravity than old and long stored eggs, because there will be a loss of moisture in the old eggs which inturn replaced by air. So the air cell will become bigger as the egg is stored for a longer time.
• Similarly, eggs having stronger shell will have higher specific gravity than thin shelled eggs.
• The measure of specific gravity can be made by several methods.
  • By measuring the egg weight and then weighing the egg in water, to find the weight loss in water.
  • By dipping the eggs in a salt solution having several concentration of salt dissolved in it; having a specific gravity ranging from 1.0-1.1 with an interval of 0.02.

A normal egg will have a specific gravity of 1.06.

• Any value less than this may indicate that the egg is old or the eggs are thin shelled; irrespective of other criteria, smaller eggs will have high specific gravity due to more uniform shell.
• By knowing the egg weight and volume.