Thursday, December 4, 2014

Vaccinating Calves - Guidelines

Dr. Amelia Woolums, College of Veterinary Medicine, University of Georgia, prepared a short list of guidelines for vaccinating young calves that have circulating maternal antibodies [these are calves that received an adequate volume of good quality colostrum soon after birth]. 

" When developing plans to vaccinate calves with circulating maternal
antibody, keep in mind the following:

a. calves are more likely than adults to require booster vaccinations,
which should be given at least 2 to 4 weeks after the initial

b. intranasal vaccines may be more effective than injected vaccines in
calves with moderate to high concentrations of maternal antibodies;
however, immunity from intranasal vaccines may not last more than
a few months;

c. repeated doses of intranasal vaccines may not boost as effectively
as repeated doses of injected vaccines;

d. calves with very high concentrations of maternal antibody, such as
those found in the first month of life in calves with good passive
transfer, may not respond as well to vaccination as calves with
moderate to low concentrations of antibody;

e. vaccines should be administered so that the final dose is given no
later than 1-2 weeks before the expected exposure of the group to
infectious agents.

I was pleased to see that she emphasized booster vaccinations and final dose no later than 1-2 weeks before expected exposure.

The protocol failures that I turn up on dairies are mostly missing the booster vaccinations and giving the final dose too close to the expected exposure (that is, before grouping or re-grouping heifers).

[Reference: "Vaccinating Dry Cows and Calves: With what, when, and is it effective at protecting the calf?', Western Canadian Dairy Seminar, March, 2014.

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