The hen's egg: Shell cracking at impact on a heavy, stiff body and factors that affect it

Publisher Website
Google Scholar
Abstract
1. Eggs from hens of three strains were dropped on to a heavy, stiff, smooth, plane body with impact at the equator of the shell; the height of drop, hc, just sufficient to produce shell failure was measured and the corresponding impact velocity, vc, calculated. 2. A small but commercially important percentage of the well‐formed eggs of one strain cracked when hc was as low as 3–3 mm and vc 250 mm/s. 3. Characteristics of the egg found to affect hc and vc included the overall thickness of its shell, thickness of its weak inner shell layer and average shell curvature, all measured at the point of impact, and its weight; its age also had a small effect (additional to that mediated through loss of weight); so did the degree of shell ridging. 4. No effect of shell colour was found. 5. Shell damage was typically a single hair‐crack that ran either round the equator or towards a pole.