Investigation of passive immunity level in calves from pregnant cattle vaccinated with bovine rotavirus vaccine for neonatal calf diarrhea

In this study, the level of Bovine Rotavirus (BRV) specific immunity in pregnant cattle vaccinated with the inactive polyvalent commercial vaccine (Rocodoll, Dollvet, Türkiye) and the status of BRV-specific passive immunity in their newborn calves were investigated. For this purpose, a total of 20 pregnant cattle, 10 of which were vaccinated (Group I) and 10 of which were not vaccinated (Group II) (control group), selected according to their gestational age, were used. Cattle in Group I were vaccinated twice in the last trimester of pregnancy, 21 days (3 weeks) apart, according to the commercial vaccine (Rocodoll, Dollvet, Türkiye) package insert. Parallel to both vaccinations, before receiving blood and colostrum/milk from cattle in Group I and Group II on the day of birth (1st day) and postpartum 3rd, 7th, 14th, 21st and 28th days, and colostrum from calves born from these animals (1 Blood samples were taken on the 3rd, 7th, 14th, 21st, and 28th days. All collected blood and colostrum/milk samples were checked for BRV specific antibody presence/titer by ELISA method. According to the determined data, the antibody level in blood serum and colostrum/milk samples of unvaccinated and vaccinated pregnant cattle, passive immunity level of newborn calves and exposure to the disease in unvaccinated animals were evaluated. A significant increase in BRV-specific antibody response (≥1/1024 – 1/256) was detected in all pregnant cattle administered the vaccine. In parallel, it was determined that the passive immunity level of BRV was high (1/1024 – 1/128) in newborn calves of vaccinated cattle that received colostrum. It was determined that natural BRV infection was formed in three pregnant cattle in the group that was not vaccinated, and passive immunization occurred in these animals. In conclusion, it has been demonstrated that it is beneficial to administer two doses of BRV vaccine in accordance with the procedure in cattle at the end of pregnancy to prevent BRV-induced neonatal calf diarrhea through maternal immunity. Keywords: Bovine Rotavirus, Cattle, Maternal Immunity, Neonatal Calf, Vaccine