TY - JOUR AU - Voitenko , Svitlana AU - Sydorenko , Olena PY - 2021/03/29 Y2 - 2024/03/28 TI - Ukrainian White-Headed breed for purebreed breeding and crossing JF - Bulletin of Sumy National Agrarian University. The series: Livestock JA - ls VL - IS - 1(44) SE - Articles DO - 10.32845/bsnau.lvst.2021.1.8 UR - https://snaubulletin.com.ua/index.php/ls/article/view/296 SP - 55-62 AB - Methods of purebred breeding with a breed of farm animals allow to preserve breed features, to fix desirable traits of ancestors in offspring, to consolidate selection groups, to improve productivity, but at a certain stage of work with it there is a problem of inbreeding and productivity reduction which are very difficult to solve. The Ukrainian White-Headed breed of cattle currently belongs to domestic local populations, in which inbred animals are present and which, given the low economically important characteristics, cannot compete not only with the world, but also with the best domestic breeds. With this in mind, the search for ways to increase the economically useful characteristics of animals and reduce the homozygosity of the population is one of the current problems. The research was conducted on livestock of Ukrainian White-Headed breed in LLC "Podilsky Gospodar" of Khmelnytsky region. The influence of bull, father of offspring and year of birth on the improvement of economically useful traits of cows in purebred breeding, as well as the possibility of using introductory crossbreeding to reduce the level of inbreeding in the herd and increase the genetic potential of cattle on the main selection traits. To determine the effectiveness of attracting white-headed Ukrainian cows to milk production on an industrial basis, we studied the effectiveness of their crossing with the Jersey breed. The main selection traits were determined based on the materials of the dairy cattle management system (DCMS "Intesel-Orsek") as of January 1,2018. It was found that the difference between the highest and lowest milk yield of Ukrainian White-Headed cows for the first lactation in 2009-2014 years of birth was 584 kg (P≤ 0.01), while the strength of the year of birth on the hopes of the firstborn was 9.4% 0.001), fat content - 18.0% (p ≤ 0.001), the amount of milk fat – 9.4%. The highest milk productivity in 3 lactations was found to be the daughters of Orel’s UA235 and Som’s UA6800085660, but in general the influence of the bull’s on cow productivity is insignificant, as the intragroup difference between milk yields between high-yielding and low-yielding daughter offspring exceeds one lactation for each of the three lactations. The strength of the bull's influence on the hopes of the firstborn was 3.4%. It is proved that the use of introductory and industrial crossbreeding increases milk productivity in crossbreed cows, compared to purebred and can be used as methods to increase the genetic potential of livestock in milk production on a breeding and industrial basis. ER -