The determination of the sex of these birds is very complicated, because only after 4-6 weeks of life the boys put out the crest and other characteristics that indicate their sex. Breeders, however, need a quicker response, and for this reason there are real professionals, who know how to interpret the numerous "signs" that appear in the backside of newly hatched chicks, decreeing sex. The operation, however, is complex and it is estimated that before learning to recognize the sex of the chicks it is necessary to observe the backside of at least 250, 000 specimens.
Professionals. The best "sexists" can also examine 1, 700 chicks per hour (gaining mind-boggling figures), giving the correct answer in 99 percent of cases. The most skilled come from Japan, which has very strict schools dedicated to their training. Neurologists maintain that the years of study have the effect of reinforcing precise cognitive and mnemonic mechanisms, which over time become automatic and allow the recognition of the sex of chicks
You might be interested
Why are chicks yellow?