It matters how your birds respond to nutritional and environmental stressors. The ability to control the response can make a difference to consistency in bird performance and wellbeing. Understanding how birds respond to stressors can help to find solutions to take control of their response.
Response to stressors at the cellular and gut level
In poultry the gut is highly responsive to stressors from the feed and the environment. High ambient temperatures, flocking density, dietary changes, mycotoxins in feed all challenge the bird and impact performance. The underlying causes to reduced performance are stress reactions at the cellular and gut level, which reduce feed intake and/or increase maintenance energy requirements.
Oxidative stress is one of the most common stress reactions at the cellular level in the animal. It is characterized by excess production of free radicals (ROS), which exceeds the ability of the bird’s antioxidant defence system to neutralise them. This is often associated with an increase in inflammatory responses and reduced gut integrity further down the line.
Building resilience to environmental and nutritional stressors in poultry
Environmental and nutritional challenges are a given for birds under commercial conditions. What matters to performance and wellbeing is how the birds respond and this is determined by their adaptive capacity and resilience.
However, continued selection for greater performance in the absence of consideration for the ability to cope with stressors has been shown to result in greater susceptibility to stressors. As a result, several research groups around the world are now putting more emphasis on finding ways of improving resilience by genetic selection in poultry. They characterize resilience as the capacity of the animal to return rapidly to its pre-challenge state following short-term exposure to a challenging situation.
Identifying relevant biomarkers in animals capable of maintaining high levels of productivity when exposed to stressors such as high ambient temperatures will help to breed for more resilient animals.
Nutrition to support a more efficient response in your birds
Research into the physiological changes accompanying the exposure to environmental and nutritional stressors is increasing the understanding of the mechanisms that the animal uses to accomplish the necessary functions efficiently. This is also helping to find ways to support a more efficient response by nutritional means to minimize the impact of those stressors on performance.
More recently attention has been paid to the transcription factor NrF2 and scientific data indicate that Nrf2 activation is one of the most important mechanisms to prevent/decrease stress-related detrimental changes at the cellular and gut level. Nrf2 is a transcription factor that responds to oxidative stress by binding to the antioxidant response element (ARE), which initiates the transcription of antioxidant enzymes, such as superoxide dismutase, glutathione, and catalase.
Research carried out by the University of Athens reported that adding a gut agility activator to the diet of broilers up-regulated gene expression of antioxidative enzymes belonging to the Nrf2/ARE pathway and down regulated NF-kB1 expression. This coincided with increased levels of total antioxidant capacity in the gut and liver.
The results suggest that adding a gut agility activator to poultry diets, could form part of feeding strategies to support the adaptive capacity of birds to take greater control of the impact of potential environmental and nutritional challenges the bird may face, enabling birds to attain their performance potential.