Utilização da vacina Escherichia coli J-5 na imunização de vacas e novilhas leiteiras contra mastites causadas por Escherichia coli

Abstract

Immunization of cows and dairy heifers with E.coli J5 vaccine in order to prevent and control mastitis caused by E.coli was evaluated. Prevalence of postpartum intramammary infections by this agent; clinical mastitis occurrence and severity in the first 100 days of lactation, and its influence on somatic cell counts (SCC) and milk yield were analyzed. Cows and heifers (n=318) were randomly assigned into five groups of vaccinated and unvaccinated animals. Immunizations occurred at dry off, 30 days after dry off and in the first week after calving. Milk samples were collected for microbiological diagnosis and SCC evaluation, and data related to clinical mastitis occurrence; its severity and milk yield were recorded.There was a reduction in prevalence of postpartum intramammary infections caused by E.coli in vaccinated cows, the same was not observed in heifers. Vaccinated cows and heifers had less clinical cases than unvaccinated group. There was a reduction in severity of clinical signs in vaccinated cows. Milk SCC did not differ between the experimental groups. Milk yield was higher in vaccinated animals. Immunization with the E.coli J5 vaccine was effective in reducing prevalence of postpartum intramammary infections, occurrence and severity of clinical mastitis and increase in milk yield in the first 100 days of lactation