Vaccinating chickens

[Marigold]

This subject has come up recently, so I wanted to do some research on what vaccinations are normally given to chicks and growers reared commercially, and find out what is involved.

Many of us with small domestic flocks will have hybrid pullets, bred from various carefully-selected breeds and strains to be reliable layers. They will have been hatched and reared commercially in very large numbers, and then at about 16 weeks old some of them will be sold on to smaller local poultry farms for resale to people like us. They will have undergone a vaccination programme designed to protect the adult flock from a variety of common and commercially devastating diseases, and we benefit from this when we buy these hybrid birds.

Here is a sample vaccination programme for a commercial flock of layers;

https://www.msdvetmanual.com/poultry/nutrition-and-management-poultry/vaccination-programs-in-poultry

And here is an outline of how and when the vaccines should be administered;

https://eorganic.org/node/7839

As you’ll see, the process is complicated and potentially expensive for a small-scale breeder of relatively few home-bred birds. The vaccines come in quantities of around 1,000 doses and once opened, they mostly have to be used immediately, sometimes within an hour or two from opening, so they can’t be saved for future use if not used up. Smaller breeders should at least give the vaccine against Mareks to their day-old chicks, but usually won’t provide the full cover against other diseases. Consequently, if you buy home-bred birds, it would be good to enquire carefully about what vaccinations, if any, they have had. There may be issues if your flock contains some birds that have been vaccinated and some that have not, as the vaccinated ones may sometimes act as carriers for the disease they are themselves immune to, and could possibly trigger an outbreak in their unvaccinated companions. This largely depends on the type of vaccine used, whether it was ‘live’ or not. This issue is complicated and my own understanding of it is incomplete, so I shall welcome more comment, research, information and corrections from those of you who are better informed.

 

[Hen-Gen]

I certainly can’t contribute to this though I did know about the transmissibility of Mareks Disease from vaccinated stock to unvaccinated. I’ve only encountered this disease once years ago among a group of Welsummers I had. This breed are said to be very susceptible to Mareks and about one third of the group died from it. Curiously the other two thirds did not even appear to contract it. There were none that had it but then recovered.
The only other thing I do with a nod to disease risk is to always use chick crumbs with a coccidiostat. I have seen the result of a coccidiosis outbreak and it is so easily prevented.
My general feeling is that chickens kept in decent, clean, stress-free environments are pretty disease resistant. Of course the day may come when I have to eat my words!

 

[Marigold]

I feel that the most dangerous time is when introducing new stock, as then you just have to take a chance that their previous environment was clean and uninfected, whether or not they’ve been fully vaccinated. The couple of weeks after they arrive do seem to be the time when apparently healthy birds go down to latent health problems, probably because of the effect of stress on their immune systems, but also because the bio-environment in their new home will be different, and therefore may be challenging to them. They may have built up resistance to any bugs present in their old home, especially if they are unvaccinated birds from a small breeder, but then meet different bacteria and viruses in the new place.

I feel that it’s probably best to either have a flock that is all vaccinated, or a purebred flock which isn’t, rather than mixing the two systems. It may also be best from the point of view of disease control to adopt an all-in, all-out policy, where you start afresh with new young birds from one single source every few years. But I know lots of people prefer to have a range of ages because their birds are well-loved pets, and there’s nothing wrong with that, if you’re prepared to quarantine and integrate new ones, and put up with declining egg numbers and egg laying problems etc in your oldies.

The best way is to keep a closed flock and breed your own replacements, as you do, HenGen, but this isn’t possible for many of us, for various reasons. Also of course if you never introduce new stock, you risk inbreeding.
I was interested in the technique of vaccinating the embryo against Mareks before hatch. If hatching an autosexing breed commercially, where all the boys would be culled at day old, a lot of vaccine doses would be wasted, but on the other hand it would save the time and logistic problems of individually vaccinating a huge flock of tiny chicks by injection.

 

[Hen-Gen]

Totally agree with all you say. In my case I avoid the dangers of introducing disease from buying in stock by only ever buying in hatching eggs. (Well, greatly reduces the danger would be more accurate).

 

[bigyetiman]

Interesting and thought provoking.
Nice to breed your own replacements if you can which not everyone can.
We choose the getting ours from a well respected supplier who vaccinates, and then keeping them, in a clean stress free environment with lots of space to roam. At the end of the day that's all you can do.
This reminded me of someone who always bought hers at fur and feather auctions, and then had them die usually sooner rather than later. Didn't matter how many times we told her to go elsewhere, she still continued. She had one lot that OH went to look at because they were poorly, they were riddled with lice. OH put powder on the first one, and it was like a Tsunami running up her arm

 

[rick]

I might be wrong about this but I really doubt than any other than the big sheds vaccinate. I.e. my local breeder has a good selection of hens in spring - maybe several batches of about 50 each of various popular breeds. Its not enough to warrant wasting most of a batch of vaccine for each hatch. I know she uses cocci growers feed because she gave me a half bag for the CLBs to finish off. The idea with the Mareks (I think) is that you vaccinate the whole commercial flock of several thousand layers and they never get out of the production cycle so it's never a problem. A tiny number of rescues get out but they are joining flocks that are relatively stress free and usually with a big garden to free range in. The rescues are stressed up to the eyeballs and have never seen real wild dirt before so are actually at the most risk anyway. Birds from a market often (not always but too often) have a worse time of it than the commercial lot!
Its just my impression - may be wrong - but I dont think it really matters that good breeders that properly look after their stock are very unlikely to vaccinate. Their immune systems are amazing so not being stressed is 99.9% of the solution.
... its much of the reason for slow introductions as well, of course. Not only does it dampen down the stress but it also gives them a chance to pick up low doses of a new pathogen through the wire and build immunity. I know I dont have a perfect record on that count - tight space doesn't help but live and learn!

 

[LadyA]

I've only kept hybrids from a large supplier. They would have all been fully vaccinated (whatever that is). I wouldn't fancy mixing them with unvaccinated stock, for the same reason as my two cats have to be indoor only. One of them is a chronic cat flu carrier. She is healthy, and vaccinated, but for some reason, still suffers the awful sneezing and snottiness she had when she was found as a tiny kitten. This means, the vet says, that the other cat is likely a carrier too. I wouldn't like to be responsible for spreading cat flu around the neighbourhood. Likewise, with the hens, I wouldn't mix them. I see on FB the problems that can arise. These days, I don't mix ages either. I use an "all in/all out" policy, and leave a couple of months at least between batches of hens. It may be coincidence, but since doing this, I've not had any sickness at all in the flock.