DIFFERENCES BETWEEN HATCHED AND NON-HATCHED EGGS FOR WEIGHT-LOSS DURING INCUBATION, SHELL COLOR, AND SHAPE INDEX

Weight loss at day 17 of incubation, shell color and shape index were compared in hatched and non-hatched groups of eggs. A total of 2654 ha tching eggs were used;the number of infertile, hatched and non-hatched eggs were 299, 2150 and 205, respectively. There was significant diff erence for weight loss (P < .05) between the fertile eggs that hatched and did not hatch, hatched eggs having smaller weight loss than non-h atched eggs. Per cent weight loss and weight loss per unit of surface area were also smaller in hatched eggs. Weight loss of infertile eggs did not differ significantly from that of fertile hatched eggs. Neithe r shell color nor shape index were significantly different between hat ched and non-hatched groups of eggs. Separately from this experiment, relationships between weight loss, shell color and specific gravity we re investigated using a total of 536 hatching eggs. Correlation betwee n egg weight loss and specific gravity was negative (-.30) and signifi cant (P < .001), indicating that eggs with higher shell strength tende d to have smaller weight loss during incubation. Correlation between e gg weight loss and shell color was positive (.28) and significantly di fferent from zero, suggesting that darker shell eggs have smaller weig ht losses.