Abstract
The objective was to evaluate subclinical mastitis dynamics and clinical mastitis monthly rate in response to use of an autogenous vaccine. Lactating dairy cows were enrolled into two groups: Vaccinated (n = 300) and Control (n = 300). To identify the herd mastitis microbiological profile, CMT test were conducted, and positive milk samples were submitted to microbiological culture. Corynebacterium bovis, Escherichia coli, Staphylococcus chromogenes, Streptococcus agalactiae, Streptococcus dysgalactiae and Streptococcus uberis showed a high isolation rate and were used in autogenous vaccine manufacturing. The first vaccination occurred in March 2022 and the booster 30 days later. Blood samples from 10% of each group were collected every 30 days for seroconversion analysis by ELISA. Data of monthly clinical mastitis and individual SCC were evaluated by T-test (GraphPad Prism; P < 0.05). Vaccination stimulated the cows’ immune system to produce specific antibodies against vaccine bacteria. The individual monthly SCC average were lower for Vaccinated than in Control group. In subclinical mastitis dynamics, Vaccinated group showed a higher number of healthy and cured cows, and a lower number of cows with new infections and chronic cows. No difference was observed in clinical mastitis rate among groups. In conclusion, autogenous vaccine appropriately stimulates immune system, reduces the individual monthly SCC average, increases the number of healthy and cured cows and reduces the number of cows with new infections and chronic cows in a crossbred dairy herd.