How to select chicken hatching eggs? Methods and techniques explained

First, the appearance should be clean, free of chicken manure, blood spots, dust, and broken egg liquid. Second, eggs should be collected more than 4 times a day. Collect hatching eggs within 7 days; beyond 12 days the hatchability drops noticeably. Third, the weight should be around 60 grams; white-shelled eggs are a bit smaller, brown-shelled eggs a bit larger. Fourth, the egg shape should be oval, with an egg shape index of 1.35 and a shell thickness of about 0.33 mm. Fifth, by candling, a fresh egg has a small air cell, thick albumen, and a yolk that does not shake violently; a normal yolk is orange-yellow or yellow. Sixth, cut it open to measure albumen height, that is, break the hatching egg onto a horizontal glass plate; a fresh egg has a large height.