BOVINE BESNOITIOSIS - TRANSFER OF COLOSTRAL ANTIBODIES WITH OBSERVATIONS POSSIBLY RELATING TO NATURAL TRANSMISSION OF THE INFECTION

Colostral antibodies to B. besnoiti were detected by immunofluorescenc e in four calves born to two Besnoitia-infected dams, with titres rang ing from 1:64 to 1:1024. A specific antibody titre of 1:1024 was found in colostrum collected from one of the dams. Two of the newborn calve s, when sampled immediately after birth, were serologically negative t o B. besnoiti, but became positive on the next day. In all the calves, antibodies were detectable up to the age of 4 months. Observations co ncerning passive transfer of antibodies from Besnoitia-infected dams t o offspring, and transmission of the infection among infected and non- infected closely kept cows, are discussed.