Morphohistological Structure of Liver in Wild Deer (Cervidae) as Indicator of Population Well-Being

Abstract

Wild ungulates are a convenient object for environmental monitoring. The authors used the histological structures in deer’s liver to assess the well-being of populations in unfavorable anthropogenic and natural habitats. The research featured liver tissues of red deer (Cervus elaphus), sika deer (Cervus nippon), and fallow deer (Dama dama). The histosections were examined in a MEIJI TECHNO microscope using the Vision Bio (Epi) software. The statistical processing involved traditional methods using the correlation and one-factor analysis of variance. The null hypothesis was rejected at an ingenuity level of ≤ 0.05. The structure of the hepatic plates, blood vessels, foci of necrosis, and inflammation proved suitable as indicators. The cell count, structure, shape, ratio of mono- and binuclear hepatocytes, as well as their nuclei and cytoplasm, were assessed by microscope. The areas of cells, nuclei, and cytoplasm, as well as the value of the nuclear-cytoplasmic index, demonstrated diagnostic significance. A number of parameters depended on age and sex. The indicators demonstrated reliable correlations. The animals had a similar histological picture, even when the samples were obtained from geographically separated areas. The samples showed pathological transformations, including necrotic foci and binucleate hepatocytes. The structure and microvasculature of hepatic plates were disturbed. Well-being assessment is a relevant issue for populations of economically important animal species. An environmental monitoring system with wild ungulates as biological indicators could improve the monitoring system for the state of biota and its qualitative parameters, as well as ensure the well-being of the livestock and the high quality of the resulting products. The obtained histomorphometric parameters can be used as reference values in the norm-pathology gradient.