I thought quite a bit before giving the pregnant ewes the anti-clostridia vaccine this season. The vaccines are not cheap. Especially so if you opt for the anti-pasteurella pneumonia product and, like me, are buying in small volumes.

The Heptavac P Plus was working out at about €1.60 per ewe, or two thirds of a lamb. If by vaccinating you saved one lamb you would have your money back. In the initial year the manufacturers recommend double vaccination, so you would have to double these figures.

The theory is that the vaccine will boost the immune system of the ewe herself for the next year and that she will pass on passive immunity to her offspring through her lambs via the biestings.

Looking at the literature the manufacturers claim about three weeks passive immunity for Heptavac vaccines and somewhat longer for the Covexin products.

Whichever product is used, introduction of so much foreign material is a cause of stress to the ewe’s system and should not be taken lightly.

The manufacturers recommend that the vaccines be given at least two weeks out from lambing, but I believe that you should move to a least a month pre-lambing.

I know that some flock owners have moved to every second year anti-clostridial vaccine for their mature ewes in order to save costs. The theory is that the ewes have built up a level of immunity that will handle most challenges.

Does this work in practice? I don’t know and it’s hard to quantify.

Last year I used Heptavac P and suffered little of no loss from clostridia or pneumonia. This year I ended up giving a half-rate vaccine and will wait to see the outcome.