VACCINATION AGAINST CONTAGIOUS
Vaccination has reduced the New Zealand average rate of contagious abortion in dairy cows from about 5 per cent to 1 per cent. However, the Department of Agriculture contends that there are still too many dairy farmers who do not vaccinate their calves. Past freedom from abortion is no excuse for not vaccinating, as infection may be introduced into a herd at any time.
Though vaccination does not begin until January or February, applications should be made now, as veterinarians and Livestock Instructors have to plan their vaccination itineraries. Late applications make this planning very difficult. Calves should not be vaccinated until they are over 4 months old, as poor immunity results if they are vaccinated before this.