total protozoa ~10^5-10^6: flagellate species 10^3-10^4 cells/ml of rumen content
||Yokoyama MG, Johnson KA: Microbiology of the rumen andintestine. In The Ruminant Animal: Digestive Physiology and Nutrition, Edited by: Church DC. Englewood Cliffs, N.J., Waveland Press1988: pp.125-144. p.130 left column
||P.130 left column: "The protozoa in the rumen number about 10^5 to 10^6 cells/ml of rumen contents. While flagellate species are present (10^3 to 10^4 per ml), the majority are ciliates. It has been estimated that the protozoa can comprise about 2% of the weight of rumen contents, 40% of total microbial N and 60% of microbial fermentation products in the rumen. The mass of the protozoa in the rumen may be equal to as much as that of the rumen bacteria."