VARIOUS METHODS OF MEASURING SHELL QUALITY IN RELATION TO PERCENTAGE OF CRACKED EGGS

An experiment was conducted to study the relationships among percentage of cracked eggs and percentage shell, shell weight per unit surface area (SWUSA), specific gravity, egg weight, or shell weight. A total of 2,325 eggs were collected from four different flocks of Hy-Line(R) W36 hens. Eggs were weighed, and specific gravity was measured by flotation method using increments of .001. The eggs were passed across a small grading machine three times to apply stress to the shells. Then the eggs were candled, broken out, and shell with membranes weighed. Correlation coefficients and simple and multiple regression equations were calculated. Highly negative correlations were found between percentage of cracked eggs and percentage of shell, SWUSA, specific gravity, and shell weight. However, a positive correlation was found between percentage of cracked eggs and egg weight. Because of the errors involved in specific gravity determination, percentage shell or SWUSA is more accurate.