The Symbols Pedigree gets its name because symbols are used to identify each ancestor. Squares are used to represent the males and circles to represent the females. When the littermates are included as part of pedigree analysis the technique is called “breadth of pedigree” and the best way to display this kind of information is to use the Symbols Pedigree. The littermates of each ancestor are also represented as either a circle or a square. As information about each individual is collected it is coded using designated colors that represent specific traits or diseases. Accounting for all of the ancestors and their littermates not only shows litter size and gender but it also provides a reliable way to track the genes being passed from one generation to the next. This approach expands the analysis and makes the information more useful.
Notice that the Symbols Pedigree codes ancestors for those that are affected, those that died and the carriers. When information is not known or has not been collected, the symbol is blank.
One of the advantages of pedigree analysis is the ability for breeders to “formula breed” and when information is misting go to a method known as “breeding-up.