As poultry farmers increasingly adopt more sustainable diets, managing the impact of β-mannans remains important for protecting bird health and performance and reducing the carbon footprint of production.
Elanco vet Tom Dutton explains how adding Hemicell™, an enzyme which breaks down β-mannans, to broiler diets can improve sustainability and protect bird performance.
What are β-mannans?
Present in most broiler diets, β-mannans are found in the cell walls of vegetable material.
When ingested, the bird’s immune system mistakenly registers them as a potential pathogen, triggering an immune response.
As a result, energy that would otherwise be used for growth is redirected towards the immune response.
“Studies show adding Hemicell to the diet can improve the carbon footprint by 3.3%1 and unlock up to 87 calories of energy2.”
How do β-mannans impact performance?
If the β-mannan concentration of the entire poultry diet exceeds 0.2%, it starts to have a significant adverse effect.
The impacts can be wide-ranging. Poor gut health impacts the bird’s ability to absorb and digest nutrients, making it harder to meet growth targets.
It also leads to more permeable gut walls and increases the risk of secondary infection. Additionally, droppings will be wetter, which has knock-on impacts on foot health.It can cause significant financial losses, both from wasted feed efficiency, and the need to treat and intervene.
Can low carbon diets help?
Soya is considered a high carbon diet because of the land required to grow it and the carbon footprint associated with importing it. While soya is particularly high in β-mannans, this is also true of other protein sources and ingredients, and even low soya diets can cross the 0.2% threshold.
Changing feed ingredients to avoid β-mannans can also lead to nutritional deficiencies.
One of the most common approaches is adding an β-mannanase enzyme, such as Hemicell, to the diet, which can break down the β-mannans before gut health is impacted.
“Using Hemicell in the diet has also been shown to reduce the incidence of pododermatitis as a result of improved gut health.”
What are the benefits of Hemicell?
Hemicell can support sustainability goals by reducing feed requirements and minimising wasted energy.
If you can improve the efficiency of feed conversion and the efficiency of the bird’s gut, it will reduce the carbon footprint.
Studies show adding Hemicell to the diet can improve the carbon footprint by 3.3%1 and unlock up to 87 calories of energy2, which would otherwise have been lost through the immune response.
Although adding Hemicell to rations carries a cost, this can be more than offset by reduced dietary calories or improved performance from the same diet.
Using Hemicell in the diet has also been shown to reduce the incidence of pododermatitis by reducing gut inflammation, and therefore aiding litter management.
Because the litter is dry, you have less buildup of ammonia which damages the skin on the feet.
What is the key to optimal gut health?
Overall, good gut health is multifactorial.
There is no single approach – you have to implement good coccidia control, cleaning and disinfection between cycles, suitable turnaround times, the correct diet, hygenic water and β-mannans control.
Every farm will have its own challenges depending on factors such as weather and water source.
Some farms have boreholes, some have mains water, so there’s different considerations for keeping that water clean. Flushing and managing water lines, and cleaning and fumigating feed bins, also play a part.
The key is looking at it in a holistic way and identifying where you can make the biggest impacts for your farm.
Find out more about making broiler diets more sustainable here.
1 Blonk consultants. (2023) A lifecycle assessment (LCA) of both Hemicell production and the comparative performance of feeds containing it.
2 Hemicell EMEA meta-analysis/field experience data.