Effect of Delignification upon In Vitro Digestion of Forage Celluloses1

Abstract

Orchardgrass forages harvested at two maturities (early and late) were ground through two screens (1 and 8 mm) and digested in vitro as intact forage and forage delignified by permanganate oxidation. Initial and residual cell wall, initial and residual cellulose and potentially digestible cellulose were greater in late intact forage than in the early. In the delignified forage, late cut forage had less residual cellulose than did the early, but initial and potentially digestible cellulose were similar. Particle size had less consistent and smaller effects upon cell wall and cellulose than did maturity. Cellulose of intact orchardgrass was 64% digested at 72 h vs 94% for cellulose of delignified orchardgrass. Digestion rate of cellulose was .0197 and .0220 logn units/hr for early and late cut intact forage and .0554 and .0719 logn units/hr for early and late cut delignified forage. Removal of the inhibitory effects of lignin increased the amount of digestible cellulose, increased the rate at which cellulose degraded and decreased the indigestible cellulose residue. Reduction in lignin could greatly improve forage intake and utilization at moderate levels of animal production.

Structural characterization of alkaline hydrogen peroxide pretreated grasses exhibiting diverse lignin phenotypes

“…Lignin removal or redistribution has an obvious impact of polysaccharide accessibility and enzymatic digestibility. Acid chlorite delignification of orchardgrass ( Dactylis glomerata L) was found to significantly improved its rate of in vitro rumen digestibility [69]. Yang and Wyman [6] showed that lignin removal in corn stover by hot water pretreatment in a flow-through reactor could be correlated to enzymatic digestibility, while hot water batch pretreatment could achieve comparable enzymatic digestibility without concomitant lignin removal.…”

Quality of Alfalfa Herbage Estimated by a Prepared Cellulase Solution and Near Infrared Reflectance Spectroscopy

“…was developed by Goering and Van Soest (1970) as The fifth procedure included soaking herbage sammodified by Darcy and Belyea (1980); samples ples in l0 mL of 0.5 N HCI for t h at 110'C were incubated for 48 h in rumen liquor followed followed by CS (ACS).…”

Composición química, digestibilidad y cinética ruminal de la digestión de residuos agrícolas tratados con explosión de vapor

“…However, increasing the fraction A of the FDA (P<0.05) is not easily explained because the cellulose remains insoluble after treatment with steam (47,48) . Moreover, the degradation of cellulose occurs when using pressure above 28 kg-1 cm 2(46) , which is higher than the pressures used in this study.…”

“…Sin embargo, el incremento de la fracción A de la FDA (P<0.05) no se explica fácilmente, porque la celulosa permanece insoluble después del tratamiento con vapor (47,48) . Además, la degradación de la celulosa ocurre cuando se utilizan presiones por encima de 28 kg -1 cm 2 (46) , que es superior a las presiones utilizadas en el presente estudio.…”