In addition to use of yield records and pedigree information in a breeding program, use of udder and teat parameters has become an improtant issue in selection of dairy ewes in recent years. In general, usefulness of including selected udder and teat traits in a breeding program is determined by heritability, repeatabilty, and peresence of high genetic and phenotypic corelation between these parameters and milk yield.

One of the methods practiced for evaluation of udder morphology is linear evaluation of udder and teat traits. Such method has of importance to determine desired traits (i.e., milk yield), and also to establish an effective and easy-to-apply selection program in dairy ewes. Linear evaluation method has also advantage of facilitating of data collection as well as allowing to work with larger populations without modification of herd management. This method requires evaluation of udder depth, udder attachment, teat position, lenght, and overall udder shape using a 1 to 9 scale. .

Since linear evaluation has not been commonly used in breeding of dairy ewes in Turkey, there is a need for information and research in this area of study. In this review, effects of application of udder and teat grading system in Turkish ewe breds on milk yield and machine-milkability, and necessity of use of such system in selection practices are discussed.