The use of visible/near-infrared spectroscopy to predict fibre fractions, fibre-bound nitrogen and total-tract apparent nutrients digestibility in beef cattle diets and faeces

Data about diet and digestion process of cattle are important for the fine-tuning from an environmental point view. Given capacity near-infrared reflectance spectroscopy (NIRS) to provide easily, quickly cheap data its ability in predicting dietary faecal chemical composition, fibre-bound N total-tract apparent digestibility (ttaD) beef were tested. The ttaD was estimated using undigestible neutral detergent fibre (uNDF) as internal marker. A total 172 pool samples 164 mixed ration (TMR) randomly collected 24 h post-feeding across fattening groups young males females Charolaise cattle. Both TMR faeces analysed chemically through visible/NIRS instrument. Calibration models developed a modified partial least squares (mPLS) regression analysis tested by leave-one-out cross-validation procedure best calibrations selected based on various parameters including coefficient determination calibration (R2CrV) residual predictive deviation (RPD). overall composition similar that reported literature variation higher than 12% most studied. NIRS able accurately predict ADF, nitrogen (N), ash content TMR, whereas only ADF prediction acceptable. true uNDF marker inaccurately predicted both (R2CrV ≤0.66; RPD ≤ 1.71).HighlightsNear-infrared not suitable technology tract digestibility.NIRS TMR.NIRS faeces.