How old did chicken feet start to bend?

Look at the chicken feet for a few years, look at the scales on the chicken feet. Every other year, the scales are smooth and rough, and the claws are usually old hens; Listening to the cock, the cock crows crisp every other year, and the old hen crows thick at ordinary times; From the appearance, the authentic old hen's fur is bright yellow, and there is obvious oil accumulation in the lower part of the chicken's stomach. Chickens have thin claws, and they have a little toe every other year. The growth period of old hens is more than one year, and the main foods are vegetables, grass seeds and miscellaneous grains.