Submitted to: Agronomy Journal
Publication Type: Abstract Only
Publication Acceptance Date: August 5, 1996
Publication Date: N/A
Technical Abstract: In vivo digestion of a forage is a function of the rate of digestion, residence time in the rumen and maximum extent of digestion, and is affected by species and maturity. In vitro rate and maximum extent of fiber digestion from 3 to 96 hrs. were determined on four different maturities. Alfalfa (Medicago sativa), Bermudagrass (Cynadon dactylon), crabgrass (Digitaria sanguinalis) and eastern gamagrass (Tripascum dactyloides) were each cut for hay after two or three intervals of regrowth. Neutral detergent residue was measured after incubation with rumen microorganisms and fiber digestion at each time interval was calculated. A single compartment model obtained a good fit for all grass samples (R2>.85). Across maturities, alfalfa had the highest rate of degradation (k=.032) but the lowest maximum extent of digestion (D=.77) and the rate of digestion did not change with maturity (k=.027). Results for maturity effects on digestion of Bermudagrass and eastern gamagrass were variable.