INFLUENCE OF LINEAGE ON THE MILK PRODUCTIVITY OF COWS OF DOMESTIC BREEDS WITH DIFFERENT HERITAGE OF THE HOLSTEIN BREED

Abstract

The results of research on the influence of the linear belonging of cows of domestic breeds and the percentage of conditional blood of the Holstein breed in their genotype on the manifestation of signs of milk productivity during four lactations are shown. The research was carried out on cows of the Ukrainian Black-and-White Dairy breed of Bell’s 1667366.74, Valiant’s 1650414.73, Elevation’s 1491007.65, Elbrus’s 897.78, Marshall’s 2290977.95, S. T. Rocket’s 252803, Starbuck’s 352790.79 and Chief’s 1427381.6 genealogical formations, which were used in the production of milk in 9 different herds under control regions of Ukraine. Representatives of the Ukrainian Red-and-White Dairy breed belonged to the Valiant’s 1650414.73, Elevation’s 1491007.65, Inhancer’s 343514.77, Cavalier’s 1620273.72, Cadillac’s 2046246.87, Hanover’s 1629391.72 and Chief’s 1427381.62 lines and were concentrated in 10 controlled herds. According to conventional blood, cows of both breeds were divided into 4 genotypic groups: 50.0–74.9% (I group), 75.0–87.4% (II), 87.5–93.6% (III) and 93.7–100% (IV). It was determined by the significant variability of milk yield of cows of both breeds in 305 days of the first to fourth lactation, which is caused by the studied genotypic factors. Only female offspring of both breeds of the Chief’s 1427381.62 line clearly increased hope with increasing Holstein heritability in their genotype for each of the four lactations. A reliable influence of lineal ownership on the manifestation of signs of milk productivity of cows was revealed. The percentage of conventional blood of cows of the Holstein breed is not a stable value for the population, since there is a constant absorption of the available breeding material by representatives of foreign origin, therefore it is not advisable to focus on a certain genotypic group when breeding cattle, with the exception of highly Holsteinized animals. It was concluded that selective crossing of cattle of domestic breeds with Holstein does not contribute to obtaining high milk productivity even in high-blooded animals close to the improvement breed, regardless of their lineal affiliation. Among the investigated genotypic factors, it is recommended to focus on the line when improving livestock of domestic breeds, as it has a significant impact on the productivity of cows and is a permanent constant in the breed hierarchy.