Abstract
This article discusses social genotypes based on the morphological and mechanical properties of the udder of first-calf heifers. For the study, 2 groups of first-calf heifers were formed, obtained by industrially crossing queens of the red steppe breed with red Estonian and Angler bulls. Assessing the overall morphological characteristics and functional properties of the udder of first-calf heifers depending on the breed of the father, it should be noted that a larger percentage of cows with the desired udder shape were in the first group (RS × А), but greater udder glandularity was found in first-calf heifers of the second group (RS × RE), the rate of lactation was higher in the second group, i.e. from the daughters of Estonian bulls.