Abstract
Baseline cytogenetic parameters in healthy livestock are essential for evaluating stress and mutagenic effects under environmental conditions. This study aimed to establish reference values of genome instability in cattle and sheep of different sex and age groups in the Almaty region. Cytogenetic analysis was conducted on “Kazakh fat-tailed coarse-wooled” sheep and “Alatau” cattle using two minimally invasive assays: the micronucleus (MN) test in peripheral blood erythrocytes and the cytome assay in buccal (nasal) epithelial cells. The research quantified genome instability and described the spectrum of cytogenetic abnormalities. Baseline values of MN were determined in both species. In cattle, MN frequency in erythrocytes and reticulocytes ranged from 0–0.5% and 0.1–0.8%, while in nasal epithelial cells the average MN level was 0.015% and other abnormalities reached 0.025%. In sheep, MN frequency varied from 0.1% to 1.2% (mean 0.31%). The mean MN level in buccal epithelium was 0.028%, whereas karyological abnormalities reached 0.04%. Comparative evaluation showed higher genome instability in females than males and in young animals versus adults, demonstrating the influence of physiological factors. The study provides reference values for cytogenetic biomarkers and identifies typical abnormalities in epithelial cells of farm animals. These results can support biomonitoring programs and improve assessment of livestock genetic health under environmental and anthropogenic stressors.