The prime factor which will influence the quality of hydrolyzed poultry feathers is the degree of hydrolyzation.
Raw feathers are high in cystine.
During the processing of poultry feathers, the cystine linkage is broken. This increases the value of feather meal. If too many cystine bonds are broken, however, sulfur amino acids are destroyed and the protein quality of the meal is reduced. Approximately 34 lbs. per cubic foot. Each lot should be of a uniform color, composition, and texture.