TRANSMISSION OF BRUCELLA-MELITENSIS FROM SHEEP TO LAMBS

Forty-one pregnant sheep showing positive immune responses to Brucella melitensis in serological or allergic tests were selected from natura lly infected flocks and kept in an isolated pen for lambing, The resul ting 62 lambs were maintained in the same pen with their dams during l actation, When the lambs were weaned, the dams were slaughtered for ba cteriological study and the lambs were reared in a clean pen. Fourteen ewes excreted B melitensis during lactation and 17 were found to be i nfected postmortem. B melitensis was not isolated from seven lambs (th ree born to infected dams) which died after birth or from eight serone gative lambs (four born to infected dams) which were slaughtered betwe en two and seven months after weaning, However, one permanently seropo sitive lamb born to a culture-negative dam was found to be infected wh en necropsied five months after weaning, The remaining 46 lambs were r eared until adulthood and slaughtered at intervals for bacteriological study, Four ewe lambs (two born to culture-negative dams) were found to be infected postmortem, but were negative in immunological tests fo r B melitensis.