A Method for Direct Viable Counts of the Facultatively Anaerobic Microflora in the Rumen of a Sheep maintained on a Hay Diet

This is the authors' abstract. We don't add key points for this paper.

SUMMARY: By direct viable counts in deep cultures in a basal nutrient agar, consisting of buffered and very highly clarified rumen liquor, supplemented only with vitamin-free acid hydrolysate of casein, tryptophan, a fermentable carbohydrate and agar, the crude wet rumen contents of a hay-fed sheep has been shown to contain a population of c. 108 viable and facultatively anaerobic bacteria per g., mostly Gram-positive cocci capable of fermenting a wide range of soluble carbohydrates including starch and inulin but not mannitol. The mannitol-fermenting population is of the order of 106 organisms per g., consisting mostly of Gram-negative rods, including coliform bacteria. Addition of reducing substances such as sodium sulphide or mercaptoacetate (thioglycollate) to the basal agar had little or no effect in increasing the counts. An extract of hay made with cleared and sterile rumen liquor did not yield the typical rumen streptococcal flora when counted by this method in raffinose + rumen liquor nutrient agar.