A Comparison of Certain Methods of Estimating Shell Strength

THE strength of egg shell is an important factor in egg quality particularly in its relation to handling and transportation of eggs. Furthermore, Munro (1940, 1942) has shown that shell strength may be indicative of the hatching power of eggs. Shell strength is an extremely variable characteristic being influenced by numerous environmental and physiological factors such as diet, rate of egg production, length of period of egg production, position of egg in the clutch, breeding and climatic conditions. Most tests for strength or thickness of shell involve physical or chemical measures which require the egg to be broken. However, the specific gravity method of Olsson (1934) provides a measure of percentage shell without injury to the intact egg whether it be used for hatching or goes into market channels. The specific gravity method has been used satisfactorily in shell quality experiments for a number of years at Ottawa. Since resistance . . .