Vashchenko, P. A.Polishchuk, V. A.Tsereniuk, O. M.Balabanova, I. A.Stadnytska, O. I.Shaferivskyi, B. S.Fesenko, O. G.Polishchuk, A. A.Ващенко, Павло АнатолійовичШаферівський, Богдан СергійовичФесенко, Оксана ГригорівнаПоліщук, Анатолій Анатолійович2026-10-272026-10-272026-09-12Polymorphism of the ADRB3 gene in Ukrainian Red-and-White Dairy cattle and its association with economically important traits / P. A. Vashchenko et al. Regulatory Mechanisms in Biosystems. 2026. №17(9), e26165. Pp. 1-9. DOI: 10.15421/02261652519-8521https://dspace.pdau.edu.ua/handle/123456789/22641Marker-assisted selection (MAS) is a promising approach for identifying genetic variants associated with economically important traits in livestock. The β3-adrenergic receptor gene (ADRB3) is involved in the regulation of energy metabolism and may influence growth, body development, and productive performance. This study aimed to characterize ADRB3 polymorphism and evaluate its associations with milk productivity, live weight, and body conformation traits in Ukrainian Red-and-White Dairy cows. Genotyping was performed in 98 cows and their paternal sires. Six alleles (A–F) were identified, with allele A predominating (0.500), while alleles B and E were rare (0.015 each). The effective number of alleles was 3.019, the Shannon information index was 1.319, and the polymorphism information content (PIC) was 0.624, indicating high genetic variability. All 96 genotyped cows were heterozygous, with observed heterozygosity of 1.000 and a negative fixation index (−0.495). All six paternal sires had the AA genotype, indicating that the alternative alleles in daughters were inherited from the maternal side. Association analysis included 90 cows with AC, AD, and AF genotypes; rare AB and AE groups were excluded because of their small size and deviation from normality. Significant genotype-associated differences were found for 305-day milk yield, live weight, sacral height, chest depth, chest width, chest girth, pelvic width, and cannon bone girth. Cows with the AC genotype had 662.2 kg (10.6%) higher 305-day milk yield and 7.47 kg (1.5%) greater live weight compared with AD cows. The AC genotype was also associated with greater sacral height and pelvic width, whereas AD cows showed greater chest dimensions, cannon bone girth, and body compactness. Significant differences were additionally detected for leg length, pelvic–thoracic, compactness, and bone indexes. The findings indicate that ADRB3 polymorphism may be a potential marker of variation in milk productivity, live weight, and body conformation in Ukrainian Red-and-White Dairy cattle. However, the specific pedigree structure and limited representation of sire families require cautious interpretation. Further studies in larger and independent populations are needed to validate these associations and clarify their biological basis.enmarker-assisted selectionmilk yieldlive weightbody conformationgenetic variabilityβ3-adrenergic receptorArticle