Influence of added microbial enzymes on energy and protein availability of selected feed ingredients

Addition of enzymes to feed ingredients results in an improved energy availability that reduces the difference between gross and metabolisable energy of the raw material. The level of improvement seen is related to enzyme type and to dosage, and correlates well with the substrate specificity of the various enzymes present. Thus the values found in this study are specific for the enzymes and dosages used. Nitrogen retention is also improved by enzyme addition but this did not show a clear dosage response with all materials. An improved nitrogen retention cannot be directly correlated with protein digestibility but an improved retention of protein may offer the possibility to reduce protein levels in the diet.