Abstract
<jats:p>The use of Holstein sires in dairy cattle breeding demonstrates variability in conformation characteristics due to breed characteristics, as well as feeding and housing conditions. Constitution and conformation are key indicators of the breeding and productive qualities of farm animals. A research and production experiment conducted at Sheminovka LLC in the Kostanay District of the Kostanay Region compared the conformation of first-calving cows based on their paternal lineage. Two groups of experimental animals were formed: Group I, consisting of the daughters of an American-bred Holstein bull, and Group II, consisting of the daughters of a domestically bred Holstein bull. The data obtained revealed that the animals in Group I had a distinct dairy type. They had a reliable superiority in height measurements by 2.1-2.4 cm (P≤0.05-0.01), in oblique body length by 2.1 cm and chest circumference by 2.8 cm (P≤0.05).</jats:p>