ECONOMICALLY USEFUL TRAITS OF COWS IN FARMS LOCATED IN DIFFERENT CLIMATIC ZONES OF UKRAINE

The article presents data on the economically useful traits of Ukrainian Black-and-White dairy cows bred in farms located in different climatic zones of Ukraine, namely: LLC SP "Imeni Volovikova " Rivne region (Polissya zone, n =1840), SE DH " Olexandrivske " Vinnytsia region (Forest-Steppe zone, n =714) and SE "Research Farm "Askaniyske" (Steppe zone, n =926). The sample includes cows that at the time of the research had completed at least the third lactation. In the controlled cows, through a retrospective analysis of zootechnical accounting data (2006-2018), live weight was studied during their growing period (newborn, 6-, 12-, and 18-month-old), reproductive performance indicators (age and live weight after the first calving, duration of the first service period), and signs of milk productivity for the first and third lactation (yield, fat content in milk, and amount of milk fat). It was found that cows from controlled farms differed among themselves in economically useful traits. The highest values of live weight in newborn and 18-month-old heifers were observed in the Forest-Steppe zone - 36.0 and 410.2 kg, and in 6- and 12-month-olds - in the Polissya zone - 176.3 and 295.8 kg. At the same time, newborn and 18-month-old heifers from the Forest-Steppe zone exceeded their peers from the Polissya zone by the mentioned characteristic by 0.4 (P<0.05) and 2.1 kg (P<0.05) and were inferior to them at 6 and 12 months of age by 2.6 (P<0.001) and 1.8 kg (P<0.05), respectively, and their probable (P<0.05; 0.001) advantage over newborn, 12 and 18-month-old individuals from the Steppe zone was 2.4; 2.3 and 7.7 kg, respectively, however, at 6 months of age the advantage was already on the side of animals from the Steppe zone – by 0.5 kg. In all studied age periods, heifers from the Polissya zone significantly (P<0.001) exceeded their peers from the Steppe zone by 2.0; 2.1; 4.1 and 5.6 kg, respectively. The highest values of the relative speed and intensity of growth of the live weight of heifers were noted in the period from birth to 6 months, with age these indicators decreased. The best average daily gains in the studied age periods (exception - the period from birth to 6 months of age) and from birth to 18 months were noted in heifers from the Joint Venture LLC "Imeni Volovikova". Instead, the highest live weight at first calving (527.9 kg), the shortest duration of the first service period (149.1 days) and the highest milk yields for the first and third lactations ( 6492 and 7167 kg , respectively ), fat content in milk ( 4.08 and 4.01%) and milk fat yield ( 264.2 and 286.9 kg) were characterized by animals from the SE "Research Farm "Askaniyske", and the fastest maturing animals (832.0 days) were those from the Oleksandrivske State Agricultural Enterprise.