Appearance characteristics, growth cycle and nutritional value. 1. Appearance characteristics: Sanhuang chicken has the characteristics of small size, "three yellow" appearance (i.e. yellow feathers, yellow claws and yellow beak), strong viability, high egg production and fresh meat. The old hen's feathers, claws and beak are not as bright and black as Sanhuang chicken.

2. Growth cycle: Due to the long growth period of old hens, chicken contains more umami substances, higher fat content and more fragrant stew than chicks. The growth cycle of Sanhuang chicken is short, and the meat quality is tender and smooth.

3. Nutritional value: The nutritional value of Sanhuang chicken and old hen is also different. Because of the different growth cycle and meat quality, the nutritional components of food are also different. Because of the long growth cycle of old hens, the content of nutrients in their meat is relatively high, especially fat and protein.