Estimation of endogenous N-losses from the digestive tract of broilers by N-balance technique and linear regression analysis: Effect of xylanase addition to a rye-based diet

摘要

An N-balance experiment was carried out with broilers in order to examine the effects of supplementation of a tallow containing rye-based diet with a xylanase-containing enzyme preparation on several measures of protein quality. The experiment was designed according to a linear regression approach yielding an estimate for basal endogenous faecal N-losses and for N-digestibility corrected for these losses which were at 91 mg.d(-1).kg(-0.67). The so-calculated N-digestibility which is termed "true N-digestibility" was estimated at 86.9% and 94.2% for unsupplemented and xylanase-treated groups, respectively.