Dietary fibre in laying hens: a review of effects on performance, gut health and feather pecking

Dietary fibre has traditionally been considered an energy-diluting component of laying hen diets. With low energetic values, and sometimes negative impacts on digesta viscosity and gut function, formulations have often aimed to minimise crude fibre contents. Increasing fibre contents can mean that the level of fat required to meet nutritional standards must be increased to account for the decrease in energy, with consequential impacts on feed handling. By contrast, recent research has shown that some dietary fibres can have beneficial effects on laying performance, driven by changes in digestibility, gut structure and function, as well as shifts in the gut microbiota. However, there is often a lack of clarity as to the quantity and type of fibre required to yield production benefits. Broadly, soluble fibres - while largely detrimental to nutrient digestibility - can act as prebiotics, favouring beneficial intestinal microbiomes, while insoluble fibres stimulate intestinal development and may have some preventative effects on feather pecking and cannibalism.