1974/04/01 by Henry L. Short, Robert M. Blair, R. Blair +1
Agricultural and Biological Sciences · Earth and Planetary Sciences · #Ruminant Nutrition and Digestive Physiology #Bioenergy crop production and management #Coal and Its By-products
paper · doi:10.2307/3800724
Cell wall constituents (CWC) were usually more plentiful in grasses than in other forages at comparable phenological stages. Acid detergent lignin (ADL) was frequently a greater proportion of the acid detergent fiber (ADF) of browse leaves than of other forages. Forbs and woody twigs usually had intermediate CWC and ADL/ADF values. CWC increased and digestibility decreased as many forages matured. The digestibility of grasses, forbs, many browse leaves, and succulent browse twigs was significantly related to true digestibility as estimated by the summative equation. Dry matter di- gestibility of mature browse twigs was significantly related to cell content values, and estimated values for true digestibility tended to exceed observed values. Foodstuffs vary in degree and rate of digest- ibility largely because of their relative fiber contents. Plants with high CWC levels, especially when combined with high lignin contents, are low-quality forage for small ruminants. J. WILDL. MANAGE. 38(2):197-209 The purposes of the present study were to determine major distinguishing charac- teristics between different types of forages and to relate these characteristics to relative digestibility estimated by the nylon bag technique in ruminally cannulated goats. A large number of grass, forb, twig, and browse leaf samples were analyzed by the comprehensive system of Van Soest (1967), and duplicate samples were subjected to in vivo microdigestion. Since fiber content is known to increase with tissue maturity, forage samples were collected at different seasons. Differences were found among forages in their fiber composition, in the compositional changes associated with in- creased maturity, and in the extent and rate at which the forages were digested. METHODS