The protection of lambs from eperythrozoon infection while suckling Eperythrozoon ovis carrier ewes. 
When lambs born to and suckling Eperythrozoon ovis carrier ewes were inoculated with heparinised blood containing large numbers of E. ovis organisms, the lambs were either sterilised of the infection or patent infection was suppressed till the lambs were weaned.  In vitro infection, transplacental transfer of antibodies or soluble antigens could not be demonstrated.