Observations upon an Unidentified Factor in Feedstuffs Stimulatory to Cellulose Digestion in the Rumen and Improved Liveweight Gains in Lambs

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Abstract
Several of the more common feeds fed to cattle and sheep were tested using the artificial rumen technique in determining the presence or absence of an unidentified factor stimulatory to rumen microorganisms in the digestion of cellulose. A limited number of feeds and cow manure extract were fractionated in different ways in characterizing the chemical and physical properties of the factor. A lamb feeding experiment was carried out using a semi-purified ration in determining the significance of the factor in stimulating appetite and weight gains in feeder lambs. The results indicated that the factor is fairly widespread in common feeds fed to cattle and sheep, both concentrate feeds and roughages. Yeast and manure extract were particularly rich sources of the material. Fractionation of these materials indicated the factor to be heat stable, and soluble in water and low concentration of ethanol. It was absorbed on Norite and eluted with acetone and ethanol. Absorption did not occur on ion-exchange columns and ashing destroyed the factor, indicating that the active material was not a mineral but rather an organic substance. Since removal of proteins by precipitation failed to remove the active principle, and various B-vitamin and amino acid supplements failed to stimulate cellulose digestion, the factor does not appear to be a B-complex vitamin or a protein. The factor stimulated appetite and liveweight gains in lambs receiving a semi-purified ration paralleling the favorable activity noted with rumen microorganisms. Copyright © . .