Immunization against bovine rotaviral infection

Area of Science:

• Veterinary Immunology
• Animal Virology
• Neonatal Calf Health

Background:

• Bovine rotavirus causes significant neonatal calf diarrhea and mortality.
• Colostrum provides crucial passive immunity to newborn calves.
• Existing vaccination strategies aim to protect calves from enteric diseases.

Purpose of the Study:

• To evaluate the efficacy of vaccinating pregnant cows with an inactivated bovine rotavirus vaccine.
• To determine if colostrum from vaccinated cows protects calves against rotavirus infection.
• To assess the impact of immune colostrum on the severity and outcome of neonatal calf diarrhea.

Main Methods:

• A field study involving 458 pregnant cows across 26 herds.
• Randomly assigned cows to vaccination or unvaccinated control groups.
• Newborn calves received daily colostrum supplements from their dams (vaccinated or unvaccinated).
• Monitored calves for incidence, severity, and outcome of diarrhea.

Main Results:

• Calves fed colostrum from vaccinated dams (immune colostrum) had significantly lower rates of diarrhea (2.8%) compared to controls (40.9%).
• No mortality was observed in calves receiving immune colostrum.
• Calves fed normal colostrum experienced severe diarrhea and high mortality (52 deaths).

Conclusions:

• Vaccination of dams with inactivated rotavirus vaccine effectively confers protection to calves via colostral antibodies.
• Immune colostrum is a critical factor in preventing severe rotavirus infection and mortality in neonatal calves.
• This vaccination strategy offers a promising approach to control bovine rotavirus in field conditions.