| The effects of Aspergillus oryzae fermentation extract, AmafermTM, on the rumen fungi Neocallimastix frontalis EB 188, Piromyces communis DC 193, and Orpinomyces ssp. RW 206, and the effects of cicer milkvetch, Astragalus cicer, on the rumen microorganisms were studied. Growth rates, protein and cellulase secretion and fungal mass production were all accelerated in the presence of Aspergillus oryzae fermentation extract. Fungal rhizoid development was increased in the presence of Aspergillus oryzae fermentation extract. Strength of fungal response increased in a dose dependent manner and demonstrated a positive correlation between cell surface area and enzyme secretion. Above certain concentrations of extract, however, the development of the fungus and enzyme secretions remained at control values or slightly diminished. These results support the idea that by accelerating fungal growth and metabolism, AmafermTM increases the rate of fiber degradation caused by rumen fungi and this, in turn, may contribute to enhance animal performance.; Cicer milkvetch (Astragalus cicer) has higher protein, ash and minerals, is higher in in vitro dry matter digestibility, and lower in fiber, ADF and NDF contents than alfalfa hay. Cicer milkvetch extract inhibited the bacterial and fungal attachment to fiber yet did not inhibit protozoal motility. The growth of rumen anaerobic fungus, Neocallimastix frontalis was inhibited by the addition of materials extracted from cicier milkvetch powder by carbon free medium, ethanol, acetone, but was not inhibited by the addition of ether extractable from cicer milkvetch. The fungal growth inhibiting factor could not be eliminated by autoclaving, microfiltration, membrane filtration, protein precipitation or proteinase treatment. Results of silica gel column separation and subsequent observation with UV/VIS spectrum suggest the fungal growth inhibiting factor may represent more than one compound. The fungal growth inhibiting factor did not contain phenol groups, aromatic rings or carbon double bonds and the molecular size of the fungal growth inhibiting factor was 1493.03. The exact chemical structure of fungal growth inhibiting factor in cicer milkvetch and its mode of action as a microbial fiber digestion inhibitor must await additional research. Such information may lead to strategies for the efficient and trouble free feeding of cicer milkvetch to ruminants. |
