Rumen Microbial Degradation of Grass Tissue Revealed by Scanning Electron Microscopy

Abstract Leaves of ‘Kentucky 31’ tall fescue (Festuca arundinacea Schreb.) and ‘Coastal’ bermudagrass (Cynodon dactylon (L) Pers.) were studied to relate microanatomical differences to differences in degradation. Leaf sections of each grass were incubated with rumen microorganisms for various times and examined using the scanning electron microscope. Data reveal that tall fescue is degraded more rapidly and extensively than Coastal bermudagrass. These differences agree with in vitro dry matter disappearance investigations conducted on leaf tissue of each grass. Portions of the lignified structures in tall fescue appear to be removed after a 72‐hour incubation, whereas all lignified tissues in Coastal bermudagrass are completely undegraded at this time. Data indicate that the amounts of particular tissues in grass leaves affect the rate of tissue degradation.