A method for determining a matchmaking quality for a first mammal in relation to a plurality of different second mammals by comparing genotypes thereof, comprises steps of providing a first database and second database. The first database comprises genotyping data of known traits and coefficients weighting severity of said traits, and the second comprises genotyping data for at least certain loci common to each of said mammals to be matchmade. In determination of value of the match first results of the coefficients weighting the severities of the traits are determined for each potential breeding pair of the first mammal with each of said plurality of the different second mammals, and second results relating to a diversity are determined for each potential breeding pair of the first mammal with each of said plurality of the different second mammals. A total result determining the matchmaking quality for each potential breeding pair is determined by combining said first and second results for each of said potential breeding pair.
