Background. The macroscopic evaluation of the color and consistency of cow uterine-vaginal mucus (UVM) samples revealed that during days 1–3 of the estrous cycle, 45.4 % of the animals in the studied sample (n = 11) had a clear-glassy color, 27.3 % had blood impurities, 18.2 %, and 9.1 % – altered coloring. Additionally, 36.4 % of the samples had thick-viscous, liquid consistency, while 63.6 % had liquid texture. Materials and methods. Mucus was collected from experimental animals at 7–8 a.m. on days 1–3 of the estrous cycle. The volume (cm3) was measured and the color and consistency of the secretion were evaluated. Indicators of mass (g) and content (%) of water (H2O), organic substances (OS), and inorganic substances (IS) were determined gravimetrically. Results. The analysis of the volume and mass indicators of native UVM samples indicates a high (˃95 %) error rate in the registered changes of H2O. However, the error in the sum of the masses OS and IS samples of dry residue (DR) components is completely different. This indicator tends to change on days 1 and 2 (Р ˂0.05), but its stable probability is detected on days 2 and 3, as well as 1 and 3 (Р ˂0.001). Stable changes in the mass OS were detected on days 2 and 3 (Р ˂0.01), while the masses of IS changed on days 1 and 2 (P ˂0.01) and 2 and 3 (P ˂0.001). In all other cases, the error exceeds 95 %. The mass percentages of H2O, OS, and IS indicate a tendency (Р ˂0.05) for changes in H2O and OS content on days 1 and 3; IS content changes on days 1 and 2, as well as 2 and 3, but the changes on days 1 and 3 are highly stable (Р ˂0.001). Stable changes in the mass of DR components were only observed on days 2 and 3. The analysis of homeostasis changes in the mass of native samples indicates that the limit of mean values of UVM:Н2О (1.02–1.04:1) ˂ Н2О:OS (67–77:1) ˂ Н2О:IS (82–439:1), but the OS:IS ratios (1.2–5.5:1) of UVM sample align with the OS:IS ratios (1.2–5.5:1) of DR samples. The limit of Сv for UVM:Н2О, Н2О:OS, Н2О:IS ratio is 0.8–5.3; 19–27; 46–93 % respectively. The OS:IS ratios of native UVM and its DR samples are the same (49; 63; 31 %). The indicators of UVM:Н2О, Н2О:IS, and OS:IS ratios suggest a tendency for change (Р ˂0.05) on days 1 and 3. Their stable changes (Р ˂0.01–0.001) were observed on days 1 and 2, as well as 2 and 3 for Н2О:IS and OS:IS ratios. Conclusion. Given the above, there is a need for further thorough investigation of the characteristics of the imbalance in the components’ mass of UVM during days 1–3 of the estrous cycle, as well as the response of secretory cells of the mucous membrane of the reproductive organs to the effects of pathological factors. This research will be applied in the development of new methods of prevention, diagnosis, and treatment of reproductive tract diseases in female animals.
