A Reflectance Method of Determining Skin and Shank Pigmentation

Pigmentation studies in the past have generally utilized either a measurement of extracted pigments or a visual subjective scoring of shanks or skin. The pigment extract procedure has most frequently involved the use of toe web discs which are extracted in acetone for 48–72 hours. The optical density or the percent transmission of the solution is then determined by a spectrophotometer and the pigment is expressed on the basis of a given area of toe web (Day and Williams, 1958). The visual scoring systems have used either a color chart or fan (Douglas et al., 1964), or have been accomplished by comparing the shanks to be tested to a set of arbitrarily selected shanks exhibiting a range of pigmentation levels (Waldroup et al., 1960). This procedure can also be used to evaluate skin pigmentation; results between experiments and among different laboratories cannot, however, be compared. It is the purpose…