Table 4 Average milk Fourier transform infrared (FTIR) prediction performance (± SD) considering the systematic effect of days in milk, parity, and genomic information (Model M4) for the batch-out cross-validation scenario of blood metabolites parameters using BayesB and gradient boosting machine (GBM) methods

Energy-related metabolites

 Glucose, mmol/L

0.74 ± 0.054

0.17 ± 0.012

1.04 ± 0.073

0.79 ± 0.051

0.16 ± 0.015

0.99 ± 0.060

 BHBA, mmol/L

0.53 ± 0.068

0.12 ± 0.034

1.05 ± 0.117

0.58 ± 0.066

0.11 ± 0.004

0.98 ± 0.078

 Urea, mmol/L

0.64 ± 0.050

0.54 ± 0.082

0.96 ± 0.093

0.74 ± 0.055

0.49 ± 0.048

1.01 ± 0.075

Liver function/hepatic damage

 AST, U/L

0.51 ± 0.093

15.34 ± 1.415

1.04 ± 0.136

0.61 ± 0.053

14.31 ± 0.828

1.01 ± 0.087

 GGT, U/L

0.53 ± 0.034

5.06 ± 0.341

1.05 ± 0.056

0.60 ± 0.043

4.95 ± 0.259

1.02 ± 0.090

 PON, U/mL

0.59 ± 0.045

12.46 ± 1.149

0.97 ± 0.095

0.64 ± 0.049

12.13 ± 0.658

1.01 ± 0.083

Oxidative stress metabolites

 ROMt, mgH₂O₂/100 mL

0.74 ± 0.040

1.58 ± 0.149

1.03 ± 0.050

0.77 ± 0.022

1.41 ± 0.152

0.99 ± 0.065

 AOPP, µmol/L

0.54 ± 0.042

5.68 ± 0.423

1.07 ± 0.073

0.63 ± 0.072

5.5 ± 0.449

1.02 ± 0.074

 FRAP, µmol/L

0.41 ± 0.084

23.58 ± 3.552

1.09 ± 0.077

0.48 ± 0.065

21.5 ± 1.572

1.01 ± 0.076

Inflammation/innate immunity

 Ceruloplasmin, µmol/L

0.68 ± 0.066

0.33 ± 0.033

0.95 ± 0.124

0.74 ± 0.056

0.31 ± 0.025

0.99 ± 0.069

 PROTt, g/L

0.77 ± 0.027

2.09 ± 0.172

0.96 ± 0.042

0.85 ± 0.040

1.87 ± 0.183

1.01 ± 0.045

 Globulins, g/L

0.82 ± 0.035

2.23 ± 0.230

1.07 ± 0.037

0.88 ± 0.025

1.96 ± 0.150

1.03 ± 0.029

Minerals

 Calcium, mmol/L

0.53 ± 0.030

0.07 ± 0.006

0.94 ± 0.099

0.62 ± 0.096

0.06 ± 0.023

1.01 ± 0.046

 Potassium, mmol/L

0.58 ± 0.069

0.23 ± 0.015

1.05 ± 0.093

0.67 ± 0.078

0.22 ± 0.014

1.01 ± 0.078

 Zinc, µmol/L

0.57 ± 0.054

1.63 ± 0.341

1.06 ± 0.085

0.67 ± 0.071

1.46 ± 0.244

1.03 ± 0.067