Economic and biological characteristics of cows with different productivity levels

The aim of the study is to conduct a comparative analysis of economic and some biological characteristics of cows with different productivity levels. The studies were conducted at the Educational and Experimental Farm of the Northern Trans-Urals State Agrarian University. The object of the study was black-and-white cows that left the herd over a three-year period and were divided into three groups depending on the milk yield during the highest lactation: production (n = 298), highly productive cows (n = 212), and record-breaking cows (n = 93). The genetic potential of record-breaking cows was slightly higher, and the heritability of milk yields in the analyzed groups did not differ significantly (h2 = 0.26…0.27). The record-breaking cows achieved their highest milk yield at the age of 2.6 lactations, which is 0.6-1.1 lactations (p 0.05) compared to individuals from other groups. Record-breaking cows had the longest duration of economic use - 4.0 calvings on average versus 2.5-3.5 calvings, and their lifetime milk productivity was 31,861 kg of milk, which is 7,510-17,257 kg more (p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }