Vashchenko, P. A.Slynko, V. H.Shaferivskyi, B. S.Myronenko, O. I.Ващенко, Павло АнатолійовичСлинько, Віктор ГригоровичШаферівський, Богдан СергійовичМироненко, Олена Іванівна2026-02-232026-02-232025-11-10Vashchenko, P. А., Skyba, M. M., Saienko, A. M., Slynko, V. H., Shaferivskyi, B. S., Myronenko, O. I., Stadnytska, O. I., & Tsereniuk, O. M. (2025). Association of PIT1 gene polymorphism with milk productivity and body conformation traits in dairy cattle. Regulatory Mechanisms in Biosystems, №16(4). Pp. 1-7. DOI:10.15421/02251952519-8521https://dspace.pdau.edu.ua/handle/123456789/20656Marker-assisted selection (MAS) is an effective approach to accelerating genetic progress in livestock by identifying polymorphisms associated with economically important traits. The pituitary-specific transcription factor gene PIT1 plays a regulatory role in the synthesis of growth hormone and prolactin, thus potentially influencing milk yield and body conformation in dairy cattle. This study aimed to investigate the distribution of PIT1 genotypes and their associations with productive and morphometric traits in Ukrainian Red-and-White dairy cows – a local breed with limited genetic characterization. Genotyping was performed using PCR-RFLP with restriction enzyme HinfI on DNA samples obtained from 51 cows. Three genotypes (AA, AB, BB) were identified with frequencies of 0.059, 0.549, and 0.392, respectively. The population was in Hardy–Weinberg equilibrium, and the Polymorphic Information Content (PIC) value (0.34) confirmed an adequate level of variability for association analysis. The frequency of allele B was twice that of allele A, suggesting moderate genetic consolidation of the herd. Cows with the PIT1 BB genotype showed a significantly higher milk yield per lactation (higher by 14.8%) and a 9.8% higher 305 day yield compared with the AB group. In contrast, genotype AB was associated with greater chest width (by 3.4%), as well as higher pelvic–thoracic and thoracic indexes, indicating a more robust body type. No significant differences were found among genotypes for milk fat content, udder morphology, milking speed, live weight, or service period duration.The obtained results demonstrate that PIT1 polymorphism affects milk yield and certain conformation indexes in Ukrainian Red-and-White cattle, primarily through mechanisms related to endocrine regulation rather than skeletal development. The presence of both alleles at moderate frequencies highlights the genetic diversity of this local breed and supports its potential use in further genomic selection programs aimed at improving milk productivity while maintaining adaptive traits.enpituitary-specific positive transcription factor 1 genedairy cattleUkrainian Red-and-White dairy breedmilk yieldbody conformationmarker-assisted selectiongenetic diversityArticle