|
|
||||||||
New Mexico State University, Las Cruces 88003
Abstract
Digestibility of organic matter in alfalfa hay, rangeland forages and purified cellulose (alphacellulose) was depressed by "soluble-silica" added to rumen cultures in the form of aqueous sodium silicate. In general, depression amounted to about one percentage unit of organic matter digestibility for each increase of 100 mg per liter (ppm) in "soluble silica" concentration for alfalfa hay, blue grama grass (cut green) and alpha-cellulose (plus glucose and urea); but the depression was greater when tobosa grass, a siliceous forage, was used as substrate. The effect of added silicate was modified by adding glucose, urea and/or a mixture of minerals (Mg, Mn, Zn, Co and Cu). The depression in digestibility due to silicate treatment involved mainly the degradation of fibrous materials in substrates rather than decreasing solubility of soluble organic matter. Availability of minerals to sustain cellulolytic microbial activity would appear to be a major factor influencing the effect of soluble silica on forage digestion by ruminants.
1 Submitted as Journal Article number 536 from the New Mexico Agricultural Experiment Station. Acknowledgment is made to R. M. Cattebeke, C. A. Arzola, Eloy Boggino and E. C. Smith who participated in some aspects of the experimentation, and to Dr. A. L. Neumann who participated in some aspects of the planning for the project.
2 Professors, Department of Animal, Range and Wildlife Sciences, and Head of Department, respectively.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |