The digestive tracts of all ruminants are normally inhabited by Protozoa. It has been held by some that these are harmful; by others that they may be helpful in the digestion of cellulose and protein. Experiments in defaunating lambs by the use of copper sulphate indicated that the infusoria are not of importance, nor necessary for normal digestion in lambs.
Proceedings of the Iowa Academy of Science
©1930 Iowa Academy of Science, Inc.
Becker, E. R. and Everett, R. E.
"Comparative Growths of Infusoria-Free and Normal Lambs,"
Proceedings of the Iowa Academy of Science, 37(1), 400-400.
Available at: https://scholarworks.uni.edu/pias/vol37/iss1/113