What are the benefits of having a vaccine programme and why is it so important for game bird health?
Ben South BVetMed MRCVS
There has been much talk in recent weeks regarding vaccinations to protect the population from COVID-19, however at St David’s in the first months of the year our thoughts always turn to vaccination protocols for your game birds as we look ahead to the next season.
Vaccinations are a very important part of preventative healthcare for the birds, and whilst they are an upfront cost for the season, it has proved to be a worthy investment to reduce the risk of larger financial costs later in the year.
In the same way as vaccines work for humans, the ones developed for game birds work by triggering the bird’s immune system to develop cells that are trained to fight against a specific disease, providing protection against future disease exposure and potential illness. There are different types of vaccines available to cover the many diseases that birds can be exposed to during their life cycle, with the development of vaccines ongoing to ensure that new variants and strains of a disease are accounted for year-on-year.
To ensure that the best levels of protection are provided to the birds, vaccine protocols are targeted and bespoke to the various life stages and environments for which they are hatched, reared and released in. With that in mind, our team of veterinary surgeons work closely alongside our clients across all parts of the game bird industry to identify disease risks and to advise on the vaccine programme that is best for them.
Traditionally, hens and cockerels are caught up off shooting ground throughout January for the forthcoming laying season. It is important to recognise that whilst birds do not always display symptoms of disease, these birds would have been exposed to many pathogens during the winter. At the practice we often see clinical outbreaks of disease at this time due to weakened energy levels in the birds and an increase in pathogen pressure as populations of birds are brought together in the rearing pens. For this reason, it is often advised that birds caught up from different areas or shoots are penned separately for an initial two week period to reduce the risk of the spread of disease. Birds should then be tested for current as well as historic disease that they have been exposed to, so as an effective vaccination protocol can be created for your flock.
The most common diseases that cause clinical issues in laying stock are Infectious Bronchitis (IB), Avian Rhinotracheitis (TRT) and Mycoplasma (MG). Early testing and identification of disease is vital in order to ensure that diseases such as Mycoplasma are either removed or carefully managed in your flock, thus protecting the health and wellbeing of the birds. TRT/IB and MG are all pathogens that can cause significant decrease in egg production sometimes up to 50% with poor recovery after the initial problem. They also lead to an increase in reject eggs and in the case of mycoplasma, passes the diseases onto their offspring. The financial consequences of a 50% egg drop or passing on MG to offspring can be astronomical and vaccines become almost an insurance policy against such losses.
Due to the early end of the season this year, gamekeepers are at an advantage as this gives us more time for testing of caught up stock, ensuring that only the best birds are kept on therefore reducing the risk of disease issues being carried into the next season.
Poults and New Stock for over-wintering
Similarly to caught up birds, birds that are intended to be over-wintered will have run out of their immune protection from their parents. As they are about to be released into the wild where they will encounter new diseases and environmental pressures it is really important that vaccinations are considered to provide the birds with increased protection during this time.
Mycoplasma is by far the most common disease we see on released game, especially in birds that have not been previously protected by a vaccine. Other viruses such as Infectious Bronchitis or Avian Rhinotracheitis can lead to significant secondary infections, with all these ailments leading to poor performance and flying ability as well as potential mortality.
Vaccines can be produced in a multiple of different ways, but they all have the end goal of stimulating the bird’s immune system to bring about future protection. Drug companies produce high quantities of commercially available vaccine that are formed from commonly seen pathogens in the poultry industry. We see cross protection when used in the game birds however we can see break throughs in mutated variants of disease and infection.
Another method of vaccine production is the creation of something calling autogenous vaccines. This is where isolates of specific pathogens collected from a bird or site are used to formulate a custom vaccine which is specifically designed to give protection against those disease strains. Autogenous vaccines have their benefits especially when looking at pathogens like mycoplasma in areas that have previously struggled to get the disease under control.
In summary, whether your stock is caught up or overwintered the same principles stand:
- Investigate and Test: Work with your local veterinary surgeon to identify what diseases that birds might currently have or have been exposed. This can be done through serology testing (blood tests).
- Vaccinate: Introducing a vaccine protocol with your vet to cover the highest risk diseases is advised as best practice. Your vet will be able to discuss the best vaccine protocol for you.
- Prevention and Planning: Ask your vet to work with you on a Veterinary Health Plan (VHP). This will ensure that the correct preventative measures are in place to look after your birds for the season and limit the risk of disease.
To ensure you have the best start to the next season, and to protect the future of your flock, please speak to your local St David’s veterinary surgeon who will be able to discuss the right vaccination and testing protocol for you. You can do this by calling 01392 872932 or by emailing email@example.com