Catching, transfer and release causes the birds stress. It’s a natural reaction from them – and invariably this will have a negative impact on their gut health. However, they can recover and there are alternatives to antibiotics that we’d encourage shoot sites to consider. It is an approach that has seen positive results in recent years, particularly with new supportive products available – such as ABC Game.
As Kenny Stokes-Nutting explains “We know that stress can drive poor gut health. Amongst the reasons for this is the hormone that’s released when the birds are stressed, as there is a hormone that’s released that helps gets them ready to flee or fight – and this can be a trigger for the guts’ mechanisms to begin to shut down.
As well as the effect of stress on the bird’s gut health, it’s also worth bearing in mind that pheasants can still be relatively young at release. Further growth is needed to reach maturity and have the strength to thrive in their new environment.”
Getting prepared
Working with your rearer to check that the birds can practice the behaviours they need at release makes for a smoother transition. This includes being able to forage, perch, drink, dust, bathe, preen, explore the environment, roost and go into hiding when they feel in danger. Where they don’t get this opportunity, we see more birds with severe health issues and disease challenges – typically a couple of days after they arrive.
Where there are gut issues – what do we see?
Pheasants and partridge have what’s known as a caecal sac in their gut, where protozoa and bacteria live in harmony, when the balance is right.
When the birds are released, they suffer dysbacteriosis – a disruption in the gut which in this case is caused by stress and a change in diet. Poults have been used to a diet of grass and pellet, at release they have access to plant material they’re not used to, and access to pellets is often more difficult – purely down to the increased amount of space between the feeders. Water hygiene is more difficult to control at release and there is also the threat from predators to contend with.
This leads to a huge ‘overgrowth’ of bacteria in the gut. This causes the caecal sacs expand – and this is when you might see diarrhoea in your poults. This can be extremely uncomfortable, and the birds might ‘look unwell’.
The traditional approach
Birds can be supported and recover. Historically antimicrobials were given. However, this destroys all the bacteria in the gut – good and bad. By doing this we’re not allowing the birds to develop an effective microbiome in response to the change in diet and stress.
Under the microscope
Where dysbacteriosis is suspected, we’ll examine samples under the microscope. We’ll see a plethora of moving bacteria that shimmers and on top of this will be the protozoa diseases – the coccidia and the motile protozoa. These are not bacteria; they are a stage up in terms of evolution and size.
The motile protozoa are ones that you might recognise as hexamita for example, and they all feed on bacteria. The bacteria in the gut ‘shift change’ the protozoa that are there. With that huge increase in bacteria, you get a vast amount of food source for those motile protozoa – and their population increases. When they get to a point where their population is too much, they themselves will drive more gut ill health. And the birds can’t cope.
The outcome with antibiotics
So, you’re now in a situation where the birds have severe diarrhoea, they’re dehydrated and won’t get to the feed because they’re so uncomfortable.
Antibiotics will work because they remove and stop all bacterial growth. Once they’ve done their job, there’s no ‘food’ left for the motile protozoa, and they start diminishing.
However, what you’re left with is a bird that has no microbiome. It’s not normal, and it’s not disrupted, it’s just not there.
An alternative to antibiotics
The research into gut health and its impact is still relatively recent and continues to evolve. However, we know that providing the birds with supportive products before, during and after transition – or at other times when they’re challenged – rather than destroying the established gut microbiome with antibiotics, can have a positive outcome. This approach can also be more cost effective.
In water or in feed products?
There are several products that can be used through the water lines such as Coccilin Plus and Parazilin. However, products in the water can be difficult on release sites.
In-feed options can be a better alternative and contain the same or similar combination of ingredients.
An example is ABC Game – introduced in 2024 by our veterinary team. It combines individual products, that have already proven successful in water, to create an in-feed alternative.
Results
Bowcombe Estate Shoot – with a large flock of partridge and pheasant – had encountered severe gut health issues, resulting in mortality, over several years. Typically, this was happening 7 to 10 days after the poults were released.
As Head Gamekeeper Russell Hatt explains “We’d experienced the same scenario over a few seasons. We were able to treat or control the situation with in-feed and in-water antibiotics, however financially this was a burden. I was keen to move away from a treatment-based approach to something that would support the birds as they transitioned to the release sites – to bolster their gut – and hopefully avoid the challenges we’d normally experience a week or so later.”
Vet Ben South explains further “Bird deaths were caused by significant diarrhoea and reduced feed intake and dehydration. Last season we tried something new to support the birds’ gut health issues, linked to stress at transfer. Stresses included changes to their commercial feed, the weather/environment, new additions to their diet from foraging, and predator stress.”
The location of pens and the fact that the birds were spread out across a large area, also made using in-water products difficult.
“ABC Game supports the birds when they are facing peak periods of protozoal and bacterial challenge – and therefore challenges to their gut health. I recommended using ABC Game for the first 6 to 10 weeks from transfer.”
Russell concludes “The results speak for themselves. For the first time in many years, I didn’t have to use in-feed antibiotics. The fact the product is applied at the mill means no there’s no extra work involved, and it was cost effective too. After the positive results of last year, we’re using the same approach in 2025.”
