Dietary fibre has long been viewed as a limitation in poultry nutrition, but Dr. Anna Rogiewicz has a different take on what increasing daily intake in poultry diets could offer. She’s taking a closer look at how homegrown feedstuffs could benefit bird health and overall sustainability, and is starting with dietary fibre – a feed component many ignore.

Rogiewicz, an animal nutritionist and assistant professor at the University of Manitoba, sees the complexity of dietary fibre as a nutritional opportunity. “I look at fibre as a very critical, functional component of feed and if we can source it locally, that would help ease our reliance on other feed sources,” she says.

Her research is focused on Manitoba-grown crops including soybeans, canola and peas that are not used as primary ingredients. They are available locally, often very nutrient rich, but overlooked for their potential as a functional food in poultry feed because of the high fibre content.

Finding the function

The trick to fibre is ensuring it’s in a form that birds can use, a challenge that’s traditionally limited its inclusion in poultry diet formulations.

“My goal is to identify the fibre properties in each of the ingredients because we need to understand these properties to be able to use new feed options effectively,” says Rogiewicz.

Dietary fibre varies in its solubility and fermentability and typically contains substantial amounts of non-starch polysaccharides (NSP) that affect its digestibility and the extent that its nutritive benefits can be utilized.

Rogiewicz is using feed enzymes that target NSP to improve the bird’s ability to digest nutrients in fibre-rich feed and to enhance the functional properties of alternative feed ingredients. Altering the properties of the fibre component in the feed makes nutrients more available and produces prebiotic-type bioactives that contribute energy to the diet and promote the growth of good gut bacteria.

While her work is focused on layer diets, there could be broader applicability to broilers. Rogiewicz says laying hens are a great model for evaluating new feed options because they are mature birds and better able to handle ingredients with more fibre and less protein. But the research and her findings are relevant because broilers, particularly at the finisher stage, may still be able to use feed ingredients with higher levels of fibre.

Sourcing local options

Rogiewicz and her team – including research associate Dr. Yanxing Niu and MSc student Poonam Neupane – have collected and analyzed the nutrient content of soybeans (full fat beans and dry extruded meal), short-season corn, canola meal, flax, oat hulls and peas.

“Many of the products we worked with could become viable feed ingredients, instead of waste, providing economic and environmental benefits to the industry.”

They added enzymes to the feed ingredients to see how well enzymes target NSP – breaking these elements of fibre into smaller, more nutritionally valuable molecules. They are looking for a process to improve digestibility and boost the functional properties of alternative feed ingredients to release extra energy and provide “food” for good gut bacteria, including Bifidobacterium and Lactobacillus.

Early results show promise

The results to date have demonstrated that feed ingredients less commonly used in laying hen nutrition can be effectively incorporated into diets as valuable sources of protein, energy and dietary fibre.

Dry exuded soybean meal contained more than 40% protein and a favourable amino acid profile. The residual oil content of cold-pressed canola expeller (what’s left after the oilseeds are crushed for oil) provided about 38% protein. And peas are becoming increasingly available for animal nutrition, particularly as a food industry byproduct.

The next step of the research is a metabolic study with laying hens. Their diet will include canola meal that’s been modified with enzymes to impact fibre and protein content and composition. Rogiewicz will be looking for the effects of this feeding trial on the gut microbiota and digestibility of the added feed nutrients.

“Nutrition research is taking a deeper look at the effect that nutritional strategies have on overall bird health, on the immune system and resilience to disease,” she says.

Rogiewicz sees opportunities for other sectors of the poultry industry as long as inclusion rates are based on the ingredients’ nutritional value to ensure a balanced diet.

This research is funded by the Canadian Poultry Research Council as part of the Poultry Science Cluster which is supported by Agriculture and Agri-Food Canada as part of the Sustainable Canadian Agricultural Partnership, a federal-provincial-territorial initiative.