IMMUNOGENIC PREPARATION AND METHOD FOR IMPROVING THE PRODUCTIVITY OF RUMINANT ANIMALS

摘要

A method of improving the productivity of a ruminant animal comprising administering to said animal an amount of an immunogenic preparation effective to invoke an immune response to at least one rumen protozoan, such that the immune response invoked at least reduces and preferably totally removes the activity of the at least one rumen protozoan. The invention also provides novel immunogenic preparations which may be used in the method of the invention.