damline

Damline is a term used in animal breeding to describe the maternal lineage of an individual, traced through its dam (mother) and her ancestors. A dam line is the sequence of female ancestors in a pedigree, often emphasized in recording and evaluating inherited traits passed through the dam, such as maternal ability, milk production, lactation, survivability of offspring, and longevity.

Breeders construct dam lines by recording generations of dams on the dam side of the pedigree, commonly including three to five generations, though deeper lineages may exist. In practice, dam line information is used alongside sire lines and overall pedigree to inform breeding decisions, select for desirable maternal traits, and assess genetic diversity within a breeding program.

Dam lines are distinct from sire lines, which trace paternal ancestry. Line breeding or inbreeding strategies may concentrate favorable traits from a particular dam line, but they carry increased risk of inherited defects if not managed with care. The reliability of dam line information depends on the accuracy and completeness of studbooks and pedigree records.

Dam line usage is common across many livestock and companion animal breeds, including horses, cattle, dogs, and poultry, where breeders may track maternal performance, temperament, and production traits. While valuable, dam line information should be integrated with overall phenotypic performance and genetic testing for responsible breeding.

See also: sire line, pedigree, linebreeding, maternal lineage.