Rumen Microbial Degradation of Grass Tissue Revealed by Scanning Electron Microscopy

TLDR

The study compares Kentucky 31 tall fescue and Coastal bermudagrass to investigate microanatomical differences. The aim was to relate these microanatomical differences to differences in degradation. Leaf sections were incubated with rumen microorganisms for various times and examined by scanning electron microscopy. Tall fescue degraded more rapidly and extensively than Coastal bermudagrass, with lignified structures removed after 72 hours in fescue but remaining intact in bermudagrass, indicating that tissue composition influences degradation rate.

Abstract

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.