What does microbiome management mean and why is it important?
The approach to supporting flocks that are unhealthy, or that have poor performance, has evolved significantly over the years. In the past, a vet would typically carry out an examination of the bird, conduct a range of tests – possibly on others in the flock too – followed by a diagnosis that was usually an infectious disease.
The microbiome – that is made up of micro-organisms including bacteria, viruses, fungi and protozoa – and its effects on animal health, was recognised where abnormalities in populations created clinical symptoms. However, the impact of the total microbiome wasn’t studied in depth until much more recently.
Avian microbiome research
There is now much research into the avian microbiome that shows how different bacteria make up eco systems in the gut, respiratory tract, skin and urogenital tracts. These bacteria work in a symbiotic way with the host bird, and get transferred to the offspring from the mother even before they hatch. From as early as 4 days old before it hatches, an embryo in an egg has a changing and developing microbiome. Although it is not clear how this bacteria gets there, what is acknowledged is that an impaired gut microbiome in the hen can lead to a challenged chick. To combat this, we focus on the mother’s health (whether it is causing obvious clinical issues or not) as this will pay dividends in the health of the day-old chick.
At research continues, there will be more reasons to support and help nurture these micro-organism populations.
Bacteria and bird behaviour
There are some bacteria that are even found to affect behaviour. This is one of the reasons that certain fibre types in rations can change bird behaviours as it encourages changes in the bacterial populations in the gut. Specific bacteria in the intestine help with digestion, whilst others produce fatty acids that promote the gut immune system to improve coccidial immunity. Research in humans shows that the various cell types in the mother’s intestine actively collect specific bacteria from the lumen and transfer them to breast milk. Such an intricate interaction between the host and its bacterial population has evolved to allow for the new born to have help developing a maternal like gut flora shows the detailed links that are now being recognised. Competitive exclusion as promoted 30 years ago is now seen to work naturally in humans and other species. The range of interactions is huge and still not fully understood.
What I know now as a vet is that rather than give a broad-spectrum antibiotic, which creates so much collateral damage to the target microbiome, I need to be more specific and careful how I treat and focus on recovery. In some cases, antibiotics are essential due to the clinical severity of the case, but our role is to also help the microbiome recover quickly.
Microbiomes throughout the production cycles
The young chick has already been in contact with a microbiome when inside the egg, both given to it by its mother as well as possible cross shell contamination. This is its first microbiome. It then hatches into an environment where there are already some pathogenic bacteria and may be next to a dead in shell chick with an anaerobic bacterial population or maybe a massive E.coli challenge. These new colonisers find niches in the developing microbiome of the chick (gut, mucus membranes, lungs etc) and might if pathogenic lead to disease or displace useful friendly bacteria.
From the hatcher to the lorry and onto the farm the chick is not living in a sterile environment, but hopefully maternal immunity and the level of challenge will allow it to survive and start developing its own beneficial microbiomes.
In the house there is the microbiome left from cleaning, the microbiome in the water lines and the microbiome of the litter. Whether these are significant populations of beneficial or pathogenic bacteria will depend on the attention to cleaning detail and the history of the previous flocks. We all now recognise that a house and a farm has its own developed microbiome which in some ways might be beneficial but in others can lead to challenges. Some types of antibiotic resistance can be linked to some detergent resistance, so not all house microbiomes are positive to the chick.
Linking microbiome management to performance
In the same way we link nutrition to health, we need to link all these microbiomes to the performance of the flock. It is here that the vet now must be more involved. We try to help the microbiome in the chick develop correctly and to do this we must also be certain that the microbiomes that impact the chick are also managed and where possible controlled.
Cleaning with the correct product to the correct level is essential, as we all know, as is water hygiene. Proper and detailed testing of the sites’ bacterial populations are essential to either support a hygiene plan or indicate where changes are needed. Each site should have a focused hygiene plan based on the health and performance history of the site which the farmer’s vet is involved in designing.
Adopting the seed, feed and weed approach
Once we have a degree of management of the farm’s microbiomes it is now very important that we help the immature chick microbiome develop by seeding it with beneficial bacteria, trying to coax these primary colonisers to develop and finally by trying to remove bad bacteria. When I first started working in poultry, we used vaccines to help develop the immune system but really only focused on antibiotics to kill bacteria, rather like throwing a weed killer on the garden. Now we see we should seed, feed and weed the garden, and do all we can to manage the microbiome wherever it is and however it impacts on our patients.
If you would like more information on microbiome management, please get in touch with your vet or call the team on +353 (0)69 61033
