@article{Ladyka_Sklyarenko_Pavlenko_Malikova_2020, title={Comparative evaluation of dairy productivity of cows of ukrainian brown milk breed of different genotypes by β-casein}, url={https://snaubulletin.com.ua/index.php/ls/article/view/221}, DOI={10.32845/bsnau.lvst.2020.3.1}, abstractNote={<p><em>In recent years, the requirements for the quality of dairy products have significantly increased, which in turn requires the use of genetic markers in breeding and the search for their relationship with the milk productivity of animals.</em><em> The study of the influence of the genotype of cows of the Ukrainian Brown dairy breed for β-casein on the indicators of their milk productivity was carried out in the Breeding Plant of the State Enterprise "Experimental Farm of </em><em>Institute of Agriculture of Northern East of NAAS" of Sumy district, Sumy region on the livestock of the Ukrainian Brown dairy breed. The determination of the beta-casein gene polymorphism was carried out in the laboratory of Institute of Physiology named after Bogomolets of NAS. Milk productivity was determined by monthly control milking. The fat and protein content in milk was determined in the laboratory of Institute of Animal Husbandry of NAAS on Bently equipment.</em></p> <p><em>Animals with genotypes A1A2 and A2A2 made up almost 90% of the studied livestock.</em><em> Based on the results of our research, we found that animals with the desired A2A2 genotype are not inferior in milk yield to animals with heterozygous A1A2 genotype and homozygous A1A1 both in the first, third, and best lactation. According to the first and best lactation, animals with the A2A2 genotype were inferior in fat content to animals of other studied genotypes, but they were superior in protein content in milk. In terms of the amount of milk fat, cows with the desired A2A2 genotype were inferior to animals with other genotypes in the first lactation, but they were superior in terms of the amount of milk protein. In terms of the best lactation, animals with the A2A2 genotype outperformed others both in terms of the amount of milk fat and protein.</em> <em>The obtained results confirm our earlier results that the use of bulls-producers with the β-casein A2A2 genotype should improve the economically useful characteristics of offspring, compared to bulls of other genotypes (A2A1 and A1A1). This will help to maintain the desired level of milk productivity and milk quality. </em></p&gt;}, number={3 (42)}, journal={Bulletin of Sumy National Agrarian University. The series: Livestock}, author={Ladyka , Volodymyr and Sklyarenko , Yuriy and Pavlenko , Yuliya and Malikova , Alyona}, year={2020}, month={Nov.}, pages={3-7} }