[shrekfeet]

question in the title really, how soon/how long can I leave it?

[jaykay]

You do them at 3-4 weeks. Earlier than that and their passive immunity from the mum's colostrum interferes with their own immune response to the vaccine. Much later than that and they're unprotected.

In practice, if you do them in batches of 'sheep cycles' for when they were born, then the oldest are 17 days older than the youngest at 3 weeks.

[plumseverywhere]

Then a booster 4 weeks later, am I right Jaykay?

[suziequeue]

Yes

[jaykay]

That's right Plums, 4-6 weeks later.

[dyedinthewool]

You do them at 3-4 weeks. Earlier than that and their passive immunity from the mum's colostrum interferes with their own immune response to the vaccine. Much later than that and they're unprotected.

In practice, if you do them in batches of 'sheep cycles' for when they were born, then the oldest are 17 days older than the youngest at 3 weeks.

Hi jaykay

A friend of mine who has had sheep for yonks (as opposed to me who has had them for 2yrs...)said her vet said lambs didn't need Heptavac-ing until they were 3months old...?  she had always done them at 6 weeks previously.

My first born lambs are now 10 weeks old I was going to Heptavac them next week-end (11 weeks) I've only 6 ewes with lambs born through the month of 5th Feb- 1st Mar.

what about withdrawal time as they are quite big, getting on for 35-40kg

It's all very confusing

[jaykay]

That's interesting Fleecewife, most folk say the passive immunity would have long gone by then.....Off to do some finding out.

No withdrawal for vaccines - I had exactly the same thought, I think it's programmed into us 

Edited to add this article, it's American but it's got a good graph in it showing the decline of passive immunity. I couldn't copy just the graph. vaccinating lambs