Immunization against Experimental Staphylococcal Mastitis in the Goat by the Intramammary Infusion of Cell-toxoid Vaccine

Abstract

SUMMARY Each of 7 goats received 2 intramammary infusions of a staphylococcal cell-toxoid vaccine, in the left side of the udder, shortly before parturition. Together with 7 unvaccinated controls, the goats were challenged 1 to 5 weeks after kidding by the intramammary infusion in the left side of the udders of 10 4 viable units of Staphylococcus aureus strain BB suspended in milk. There was a marked staphylococcal alpha antitoxin response to vaccination, and a smaller increase in staphylococcal agglutinin levels in the vaccinated goats, in samples of serum and milk collected at parturition and challenge. Clinical observations, milk yield measurements, bacterial and leucocyte counts on milk samples and the post-mortem examination findings 10 days after challenge all indicated that the vaccinated group of goats was more resistant to challenge than the control group, although infection of the udders with strain BB was established in all the vaccinated goats. Vaccinationreduced the milk yield in 5 goats, and evidence of mammary involution was detected histologically in 4 of these.