10^6 - 10^7 CFU/ml
||Bacteria Streptococcus bovis
||Letarov A, Kulikov E. The bacteriophages in human- and animal body-associated microbial communities. J Appl Microbiol. 2009 Jul107(1):1-13. doi: 10.1111/j.1365-2672.2009.04143.x. p.6 left column top paragraphPubMed ID19239553
||Iverson, W.G. and Mills, N.F. (1977) Succession of Streptococcus bovis strains with differing bacteriophage sensitivities in the rumens of two fistulated sheep. Appl Environ Microbiol 33, 810–813. AND Tarakanov, B.V. (2006) The Phenomenon of Bacteriophagy in the Rumen of Ruminants. Moscow: Nauchny mir.PubMed ID326185
||P.6 left column top paragraph: "Coliform bacteria (>80% of them generally are E. coli) are normally present at 10^5–10^8 CFU/g in human and
animal faeces (BNID 112506). Streptococcus bovis is present at 10^6–10^7 CFU/ml of sheep rumenal fluid (primary sources). These cell densities are well above the reported threshold level of about 10^4cells/ml for exponential phage growth (Wiggins and Alexander 1985). Thus, some mechanisms stabilizing the coexistence of phages and their hosts have to be present."