VARIABILITY OF SELECTION TRAITS IN COWS DEPENDING ON THE COUNTRY OF BULLS SELECTION
Authors: Kuziv M. I. , Fedorovych Ye. I. , Kuziv N. M. , Fedorovych V. V. 
Published: August 2022

Goal. To investigate the variability of selection traits in Ukrainian Black-and-White cows of dairy breed depending on the country of selection of bulls. Materials and methods of research. The research was conducted in the State Enterprise "Oleksandrivske" of Vinnytsia region on first-borns and adults (III lactation) cows of the Ukrainian Black-and-White dairy breed. To study the country's influence on selection of the father on the variability of selection traits of cows formed groups of daughters of bulls of different breeding countries. A total of 714 cows were included in the sample. In controlled cows by retrospective analysis of zootechnical accounting data for the last ten years studied the dynamics of live weight during breeding at a young age (newborns, 6, 12 and 18 months), reproductive capacity (age and live weight at first calving, duration of the first service period), milk productivity (yields, milk fat content and amount of milk fat). The strength of the influence of the country of selection of the father on the variability of milk yield, fat content in milk and milk fat yield was determined by one-way analysis of variance.

Research results. It is established that economically useful traits of cows depended on the country of selection of the bull. The smallest difference in live weight in the period cultivation was observed in newborn animals. Yes, between the descendants of bulls selection of the United States (highest value) and Hungarian selection (lowest value) difference was 2.2 kg (P < 0.05). In 6-; 12 and 18 months of age with the highest live weight characterized by daughters of bulls of n selection. It is established that the highest living the daughters of Russian bulls were noted for their mass and the oldest age at the first calving selection. By the duration of the first service period in the offspring of bulls of different selection, compared with the highest value of the probable difference is not detected.

During the first lactation, the highest milk yield (6269 kg) and milk fat yield (223.6 kg) had the daughters of bulls of German selection. In terms of milk yield, they probably outnumbered their peers Canadian, Russian and Ukrainian selection for 1323 (P < 0.001), 1083 (P < 0.001) and 327 kg (P < 0.05), respectively. The yield of milk fat of the daughter of bulls of German selection is likely (P < 0,001) dominated by offspring of bulls of Canadian selection by 43.7 kg, Russian selection – at 37.6 kg. Between the daughters of bulls of German selection and the descendants of the offspring of others studied selection for milking and milk fat yield no significant difference detected. For the third lactation with the highest milk yield (7120 kg) and milk fat yield (253.5 kg) descendants of Ukrainian breeders were noted. According to these indicators, they are probably (P < 0.01–0.001) dominated by daughters of bulls of Dutch selection by 1101 kg, Hungarian – 894 kg and incredibly – descendants of bulls of Canadian, German, Russian and American selection for 6–538 kg and 3.2–21.0 kg.

Descendants of bulls of Canadian selection were noted for the highest fat content in milk first lactation (3.66%). They probably (P < 0.001) outnumbered the daughters of German bulls selection by 0.07% and American – by 0.08% and incredibly – the descendants of bulls Dutch, Russian, Hungarian and Ukrainian selection by 0.01–0.05%. For the third lactation, the highest fat content was in the milk of daughters of breeders of Dutch selection (3.59%). However, the probable (P < 0.05) advantage in this indicator they had only over peers derived from bulls of Russian selection and it was 0.06%. The country of breeding bulls had a significant impact on the hopes and yield of dairy fat of their daughters. In the first-born the strength of the influence of the country of selection of the bull on hopes made 11.9%, on the yield of milk fat – 10.9%, and in adult cows – 4.5% and 4.3%, respectively P < 0.001 in all cases. The country of selection of breeding bulls significantly influenced the content fat in milk for the first lactation (8.7% at P < 0.001), and for the third lactation the force of influence was insignificant (0.9%).

Conclusions. The economically useful traits of cows were influenced by the country of selection of their parents. The highest live weight in most age periods was observed in the offspring of breeders Russian selection. The lowest live weight and the youngest age at the first calving and the daughters of bulls were characterized by the shortest duration of the first service period Dutch selection. The highest milk yield and milk fat yield for the first lactation was marked by the descendants of bulls of German selection, and the third – Ukrainian selection.

The most fat-milk for the first lactation had the daughters of Canadian breeders, and for the third – descendants of breeders of the Dutch selection. Country of breeding bulls had the most significant impact on the formation of milk productivity of first-borns.