Vaccination of back yard poultry is a topic we frequently discuss with customers, clients and vets alike. It is to a degree and area of mystery; causing confusion due to conflicting information and discussion on blogs, the uninitiated giving unfounded advice on a complex subject!
The number of commercial laying hens in the UK stands at around 35 million. In order to protect these birds from many poultry diseases they have to be vaccinated. Poultry diseases would either cause death and health issues with serious egg production drops, deeming loss of eggs to feed the nation and of course economic crisis for the egg producers. Examples of the diseases which birds are given protection from vaccines are Infectious Bronchitis, Marek’s Disease, Salmonella, Laryngiotracheitis, Gumboro disease, and Newcastle Disease. There are many others, all of which are given at specific times and in specific way; usually via the water as a drink, injected or as a spray vaccine. This is why it is complicated. Vaccines are given following veterinary advice from diagnostic findings in previous and present flocks of birds. The vaccination process starts from day old and carries on to about 16 weeks of age in the laying hen.
Back to the hobby and smallholder flocks. The size of flock kept is much smaller than commercial flocks; therefore pressure of disease is far less. This is good news in many respects, however, one thing hobby keepers like doing is collecting birds from many different sources! Doing this creates challenges for the flock as different sources of birds will have met different disease challenges. These situations tend to incur disease and problems. Actually vaccinating as a result of disease is a tricky business unless carried out with care and understanding of the situation. It is important to diagnose the disease in the first place rather than guess what it may be. Many poultry diseases give similar symptoms, particularly respiratory diseases. Vaccination alone will not give you a healthy flock. The management of the birds and preventing mixing of different ages and origins is also essential when a vaccine program is implemented. Vaccine program following disease are very much bespoke to the situation in hand. Keeping a closed flock (not buying birds or hatching eggs in) and isolating any new birds for 28 days is another proven way of reducing disease.
Commercially all eggs sold into retail for table use (class A) farmers have to be registered and adhere to a strict code, the Lion Code (you can find full details of this here www.egginfo.co.uk) part of the National Salmonella Control Program (NCP), a food safety move to protect the public from the incidence of food poisoning through Salmonella Enteritidis. Part of the code covers vaccinating the birds with salmonella vaccine to ensure that the eggs they produce are not infected with salmonella, plus many other management implementations to keep the eggs clean. No washed eggs are put into supermarkets for example from Lion Code farms. Washing eggs removes the protective waxy cuticle layer on the shell of the egg which prevents bacteria entering. Any eggs which are not class A automatically go into class B and these need to be heat treated/pasteurised.
As a side issue if you have less than 50 birds you are able to sell ungraded eggs directly to consumers. If you have up to 350 birds you need to register for a producer code so your eggs are stamped and therefore traceable should there be a problem. Over 350 birds the producer must register for a producer code and adhere to the NCP plus other legislation on egg labelling and marketing. Anyone with 50 birds or more must in addition register with DEFRA, as simple and free registration to assist in knowing where numbers of poultry are in the event of a notifiable disease outbreak. Further information can be found at www.gov.uk
With regards to vaccination for salmonella in small flocks it is mainly a matter of expense and practicality. Most poultry vaccines are only available in single disease strains with a minimum of 1000 doses. These are live viruses or bacteria which need to be administered within a few hours after reconstitution (mixing). The salmonella vaccine is given in the water 3 times between a few days old and 14 weeks of age. This would cost a few hundred pounds making it uneconomic and not very practical for a newly hatched group of chicks. It is not possible to vaccinate an adult bird for salmonella as the salmonella bacterium will have manifested within the bird already. There are injectable forms of salmonella vaccine, however 2 doses are required and again the pack size is 1000 doses.
Hygiene is the tool you can use to cut down risk with unvaccinated birds. Chickens unvaccinated for salmonella will carry salmonella bacteria in their droppings, therefore it is very important to keep the eggs as clean as possible. Ensuring there is fresh clean bedding (shavings are best) in the nest boxes is the most proactive way to keep the eggs clean. Making sure that everyone who handles chickens and their eggs thoroughly washes their hands afterwards. Storing eggs which are clean and not handling other food stuffs after touching dirty eggs all greatly reduce any risk. We frequently have concerns raised from schools with small flocks. The droppings from unvaccinated birds my carry salmonella. If birds are showing no signs of ill health, the coop and nests are kept clean and the staff and children wash hands there is little risk to contracting salmonella from eating eggs from unvaccinated hens. Purchasing already vaccinated pullets removes any concerns. It is prudent for schools to check their public liability insurance with reference to this subject should they feel the need to do so.
In summary seek veterinary diagnosis in the first instance if you are considering vaccinating your flock due to suspicion of disease. If you are in a situation where vaccination is not practicable then hygiene and a closed flock are the greatest defence in the reduction of disease. This is a vast topic and a short article does not do it justice, but hopefully some of this information will assist you in understanding more about vaccinating poultry.
