The Effect of Air Temperatures on Egg Shell Thickness in the Fowl

Abstract IT IS a well known fact that egg shells usually become thinner during the spring and summer. Miller and Bearse (1934) determined the shell percentages of eggs from December to October and found a more or less consistent decrease beginning in March and extending throughout the period. Variations of the percentage of the egg which is shell should be closely associated with shell thickness or strength. The results of these investigators suggest the possibility of some environmental factor which comes into play in the summer and reduces shell thickness. There is also the possibility that there is a fatiguing effect of a long period of continuous laying, resulting in a thinning of the egg shells produced at the end of the laying year. In an experiment recording the influence of high environmental temperatures on egg weight, Bennion and Warren (1933) recorded the fact that the egg shells seemed to be . . .