@article{Khmelnychyi_Martynova_Mykytiuk_Kryvchenko_Miadelets_Naumenko_2021, title={Longevity of dairy cows depending on breeding methods}, url={https://www.snaubulletin.com.ua/index.php/ls/article/view/303}, DOI={10.32845/bsnau.lvst.2021.1.15}, abstractNote={<p><em>The duration and efficiency of lifelong productivity of cows of Ukrainian Black-and-White dairy breed of different blood by Holstein breed and purebred Holsteins of domestic selection of stud herd were studied. Within the genotypes, four experimental groups of crossbreed cows were formed, taking into account the conditional blood by Holstein breed: I group 3/4-blood; ІІ group - 7/8; III - 15/16; IV - 31/32.</em> <em>It was found that the best indicators of productive longevity were determined purebred Holsteins of domestic origin compared to crossbreds obtained by absorbing crosses with sires of Holstein breed. The longest lifetime (2633 days) and the largest number of lactations during life (5.2) were characterized by cows with a conditional share of Holstein heredity 3/4.</em> <em>When comparing purebred Holstein cows with domestic animals of groups I and II, the highly reliable difference in favor of hybrid cows in terms of lifetime was 378 and 289 days, respectively (P &lt;0.001), and in terms of lactation - by 1.3 and 0.9 pieces (P &lt;0.001).</em> <em>The growth of Holstein breed heredity did not lead to appropriate reduction of lifetime milk yield in the crossbreed animals. From the group of purebred Holstein cows with a share of Holstein blood 96.88% was obtained the highest lifetime yield (30327 kg) with the excess of cows group’s of other genotypes by 1575-4615 kg of milk with a reliable difference compared to hybrid genotypes of groups I-III (P &lt;0.001 ). With high reliability, purebred Holsteins were dominated by the corresponding crossbreed groups in the lifetime yield of milk fat, respectively, by 68.1-164.6 kg (P &lt;0.001). The milk yield of purebred Holstein cows for one day of life amounted 13.4 kg with the superiority of other cows group’s of hybrid genotypes by 1.2-3.6 kg with a high degree of reliability (P &lt;0.001).</em> <em>A positive correlation has been determined between the share of Holstein heredity and lifespan, the number of used lactations, lifelong milk yield, milk fat and milk yield per day of life. The level of conditional blood share did not affect the fat content in milk. As the inheritance of the Holstein breed increased, the correlation dependence of longevity traits on the Holstein heredity decreased significantly.</em></p&gt;}, number={1(44)}, journal={Bulletin of Sumy National Agrarian University. The series: Livestock}, author={Khmelnychyi , Serhii and Martynova , Yuliia and Mykytiuk , Petro and Kryvchenko , Tetiana and Miadelets , Vitalii and Naumenko , Maryna}, year={2021}, month={Mar.}, pages={103-109} }