Digestibility

Composition is not nutrition

Two ingredients with the same proximate analysis can perform very differently. Processing intensity, anti-nutritional factors, fibre matrix and particle size all move digestibility while leaving the proximate profile unchanged.

Practical proxies for buyers

Full digestibility trials are impractical per shipment. Buyers use proxies: protein dispersibility index and urease for soy products, pepsin digestibility for animal proteins, reactive lysine for heat-processed proteins, and starch gelatinisation for extruded materials.

Was zu prüfen ist

—Which species and life stage the digestibility coefficient refers to
—The proxy test result relevant to the process route
—Whether the value is measured, predicted or copied from a published table

Typische Risiken

—Overestimated nutrient supply in the formulation matrix
—Batch-to-batch variability that averages out on paper but not in the barn

Häufige Fehler

—Transferring poultry coefficients to aqua or swine diets
—Assuming digestibility is stable across origins and seasons

Häufige Fragen

Can digestibility be written into a purchase contract?

Directly, rarely. In practice buyers contract the measurable proxies — urease activity, KOH solubility, pepsin digestibility, reactive lysine — which correlate with digestibility and can be verified on a sample.