Growth features of young Holstein cattle, depending on the origin
The article presents the results of a study on the growth of young Holstein breed depending on the sex and origin of the animal. As a result of the study, it was established that at the age of one year, the heifers of the Texas 1771 bulls and the 5827 Malibu bulls have almost the same live weight. The live weight of the heifers of the Balaton 1777 bull at this age is 2.13 kg and 5.32 kg more than that of the daughters of the bulls Alcor 73 and Stalker 1425, respectively. The live weight of bulls obtained from bull Malibu 5827 at one year of age is more than bulls obtained from bull Alcor 73, Blaton 1777, Stalker 1425 and Texas 1771 by 4.7%, 6.6%, 12.4% and 5.2% respectively. Under the same conditions for feeding and keeping heifers and bull calves from birth to one year of age, the growth rate of bull calves is higher than that of heifers obtained from different sire bulls. It was reliably established that at the age of one year, the live weight of bulls by fathers, which were the bull Alkor 73 by 7.2% (p≥0.99), the bull Balaton 1777 by 4.6% (p≥0.99), the Malibu bull 5827 by 8.7% (p≥0.999), more than their daughters. The average daily gain in live weight of bulls is also greater than that of heifers. So, in bulls obtained from bull Alcor 73 by 7.0%, bull Balaton 1777 by 5.7%, Malibu 5827 by 9.5%, bull Stalker 1425 by 2.4%, bull Texas 1771 by 4.1% , compared to chicks. Consequently, the growth rate of Holstein bulls is greater than heifers, especially those obtained from bulls - Malibu 5827 and Alcora 73. Heifers and bulls obtained from bulls Malibu 5827 and Texas 1771 are characterized by a higher live weight at one year of age.