A dynamic model to measure retention of solid and liquid digesta fractions in chickens fed diets with differing fibre sources

•Digesta retention time in broilers was predicted using a dynamic modelling approach.•Dietary fibres modulated retention time, mainly in the gizzard and caeca.•Caecal retention of liquid digesta (500–1 500 min) was longer than previously assumed.•Fibre digestibility was increased by fibre inclusion, regardless of fibre source.•Model output can be used to fine-tune feed formulation models.