This investigation evaluated the efficacy of a bacterin in reducing the prevalence of staphylococcal mastitis
and somatic cell counts (SCC) in a dairy goat herd. Does were vaccinated or left as controls, and the
levels of mastitis and SCC monitored over 18 months. Staphylococcus caprae (42.5%), S. xylosus (15.1%),
and S. simulans (10.0%) were the predominant causes of intramammary infections (IMI). The infection
rate was 1.64 IMI/doe among vaccinates, which tended to be lower (P < 0.12) than controls (2.67 IMI/
doe). The spontaneous cure rate of IMI after immunization was 1.28 cures/doe in vaccinates, which was
higher than controls (0.6 cures/doe; P < 0.043). Average SCC of milk samples from vaccinates tended to
be lower than that of controls (1274 × 103/ml vs. 1529 × 103/ml, respectively) (P < 0.10). Results support
the continued study of mastitis vaccines for use in managing staphylococcal mastitis and SCC in dairy
goats.