Seasonal Effects on the Ultrastructure of the Ruminal Mucosa Epithelium and Ruminal Bacteria in the Fallow-deer (Dama dama L.)

Abstract

The multilayered epithelium of ruminal mucosa in fallow-deer was investigated in the course of four seasons of the year. A total of 16 animals was studied, with 4 individuals in each group. Except for winter when they were offered additional feed, the animals grazed. Excisions of ruminal mucosa were processed using the routine methods for electronmicrospical study. Cells of the multilayered epithelium were compared within experimental groups (spring, summer, autumn, winter). Each layer of the epithelium consisted of typical cells (basal, parabasal, intermediary, granular, transitional, keratinized). Intercellular spaces of different widths were found in individual layers and groups of animals. The widest spaces were found in the basal layer in the groups spring and summer. Cytoplasmic projections of adjoining cells were connected by desmosomes. Mitochondria, indicators of metabolic processes, were most numerous in the basal and intermedial cells in animals studied in the spring and summer. A continuous layer of transitional cells was found in summer and partially in spring. Ruminal bacteria were found to adhere to the surface of keratinized cells and also among ther cells. It is concluded that the observed seasonal changes in ruminal mucosa of the fallow deer are a result of mucosal adaptation to various types of diets.