Determination of Plant-Environment Interactions That Promote Bloat in Grazing Cattle
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Frothy
bloat is the major non-pathogenic source of death loss and lost weight
gain in wheat pasture-stocker cattle systems in Texas.
Losses to the stocker cattle and dual-use wheat industries of Texas exceed $20 million per year. Research we have conducted over the last two years has shown that bloat is a multi-axis problem that no one environmental, animal or management factor catalyses or alleviates. |
Rationale
Bloat has historically been associated with lush growth of pasture forage that is low in fiber, high in soluble proteins and moisture. Small grain forages contain high concentrations of highly soluble proteins, yet bloat occurs irregularly in cattle grazing wheat pastures and the specific reasons for its occurrence are not known.
Condensed
polyphenolics (tannins) present in certain forage plants reduce bloat incidence
because of their ability to bind to soluble proteins and interfere with protein
degradation by rumen microbes. Wheat produces tannins and a range of other
phenolic compounds that may affect bloat incidence. Phenolic compounds play an
important role in plant protection against ultraviolet radiation and oxidative
stress; thus, their metabolism may be affected by environmental factors.
The
relationships between environmental factors (light quality and intensity,
temperature, moisture, soil physics and chemistry) and plant biochemical
processes are well known. We hypothesize that specific interactions
between light intensity and quality, and temperature may interfere with phenolic
compounds synthesis and degradation pathways in wheat
forage, affecting the occurrence of bloat in grazing cattle.
Objectives
The objectives of this research are 1) to identify the relationships between changes in light and temperature, and phenolic content in wheat forage, and 2) determine the role of phenolic compounds in forage on the activity of rumen microflora and the occurrence of bloat.
Status
A second-year data (2006) are being collected in cooperation with Dr. William E. Pinchak, and Dr. Byeng-Ryel Min (TAES Vernon, TX).
