The Relationship of Specific Gravity, 14-Day Incubation Weight-Loss and Egg Shell Color to Hatchability and Egg Shell Quality

Relationship between egg‐shell colour and two measurements of shell strength in the Vasca breed

“…Similar correlations between shell colour and specific gravity have been reported by Godfrey (1949), Godfrey and Jaap (1949) and Grover et al (1980), and between shell colour and shell thickness by Godfrey (1949) and Godfrey and Jaap (1949), though Carter (1975) found a significant negative correlation between shell colour and shell thickness. The high and significant negative correlation reported by Carter (1975) between egg-shell colour and incidence of shell faults, emphasises the beneficial effect of shell colour on strength.…”

“…The high and positive significant correlation found between specific gravity and shell thickness shows the strong relationship between the two methods of assessing shell strength, in good agreement with Godfrey (1949), Godfrey and Jaap (1949), Frank et al (1964) and Marks and Kinney (1964).…”

“…There are few results concerning the relationship between shell colour and shell strength, and none is conclusive. A relatively small but significant positive correlation coefficient was reported by Godfrey (1949), Godfrey and Jaap (1949) and Grover et al (1980) between shell colour and egg specific gravity and by Godfrey (1949) and Godfrey and Jaap (1949) between shell colour and shell thickness. Potts and Wash-467 burn (1974) found no significant correlation of shell colour and four measurements of shell strength (egg specific gravity, shell thickness, non-destructive deformation and breaking strength).…”

Strain Differences in Egg Shell Mottling, Internal Quality, Shell Thickness, Specific Gravity, and the Interrelationships Between These Factors

“…The coefficient of correlation obtained from the February experiment ( + .693) was probably lower than the others because the workers were not skilled in taking accurate measurements with the shell thickness gauge. Godfrey and Jaap (1949) obtained a coefficient of correlation as high as +.919 for specific gravity and shell thickness. Mountney and Vanderzant (1957) also found a significant correlation between specific gravity and shell thickness.…”

The Influence of Rate of Production and Temperature on Egg Shell Color

“…Funk and Forward (1949), using a three point scale found that dark brown eggs hatched significantly better than medium brown and medium brown eggs significantly better than light brown in New Hampshires. Godfrey and Jaap (1949), using a seven point scale ranging from white to darker than Ridgway's vinaceous cinnamon found a significant correlation between shell color and hatchability of all eggs set and hatchability of "non-clear" eggs in Oklahoma strain New Hampshires but not in Ohio strain birds.…”