Author
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AKIN, DANNY |
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Submitted to: Nutrition Conference Proceedings
Publication Type: Proceedings Publication Acceptance Date: 9/13/1995 Publication Date: N/A Citation: N/A Interpretive Summary: An interpretive summary is not required for a literature review, book chapter (unless reporting original research), book review, or oral presentation (where only the title or abstract is published. Refer to directive 152.1 4/3/91 Technical Abstract: Lignin and aromatic constituents in plant cell walls are the most limiting factors in digestibility. Cell types such as xylem are heavily lignified and mostly resistant to microbial degradation. However, low molecular weight compounds, such as ferulic and p-coumaric acids, occur in non- lignified cell walls and can influence digestibility. For example, mesophyll and parenchyma bundle sheaths can be poorly digested in plants undergoing environmental stress, which increases the amounts of aromatics in non-lignified cell walls. These compounds appear to be a major factor influencing digestibility in parenchyma of many grass stems. Plant maturity is the major influence on cell wall aromatics and is, therefore, the major detriment to degradation of plant cell walls and to forage quality generally. Among the environmental factors, increased temperature appears to generally increase cell wall aromatics and directly reduce digestibility, with a greater and often substantial effect on stems. Temperature further affects forage quality in that plants adapted to grow in warm climates generally have more anti-quality characteristics than those adapted to temperate climates. Other stress factors are inconsistent and generally exert a small effect when compared with temperature increases. Results on a few grasses indicate that enriched CO2 concentrations generally do not alter forage digestibility. Of the challenges for the future, indirect effects of enriched CO2 levels, i.e., increased temperature and altered precipitation patterns, on plants require monitoring as these factors appear to more directly influence forage quality than additional C for plant growth. |
