BOVINE VIBRIOSIS VACCINATION

An adjuvant vaccine was prepared from an Australian isolate of Campy-lobacter fetus subsp fetus biotype intermedius and injected into 23 virgin Guernsey heifers. Ten nonvaccinated animals served as controls. When challenged by the intravaginal route with a culture of either the homologous strain or biotype venerealis, weekly swabs from the anterior vagina continued to yield either biotype in 8 of 10 nonvaccinates at 6 weeks as compared with 3 of 23 vaccinates. Serology in vaccinated heifers and rabbits showed that the vaccine produced high titres of antibody against both homologous and heterologous strains.     

THE EFFECT OF BOVINE EPHEMERAL FEVER VIRUS ON THE BOVINE FOETUS

Six pregnant heifers that were experimentally infected with bovine ephemeral fever virus produced normal calves. Foetuses of 8 heifers that were immune to bovine ephemeral fever were inoculated with bovine ephemeral fever virus. One was aborted after 36 days, but the cause of abortion could not be determined. One was sacrificed after 28 days. The foetus and its membranes were normal and neither virus nor antibody was demonstrated. The other 6 heifers produced normal calves. One calf, 501, inoculated after 160 days gestation, contained high levels of neutralising antibody in serum before ingestion of colostrum. The others, inoculated at gestational ages of 52 days to 157 days showed no evidence of neutralising antibody in blood samples collected at birth.