Table 3 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 tenfold random cross-validation scenario of blood metabolites parameters using BayesB and gradient boosting machine (GBM) methods

Energy-related metabolites

 Glucose, mmol/L

0.80 ± 0.035

0.16 ± 0.008

1.03 ± 0.074

0.85 ± 0.029

0.14 ± 0.008

1.02 ± 0.044

 BHBA, mmol/L

0.59 ± 0.059

0.11 ± 0.009

1.04 ± 0.097

0.62 ± 0.053

0.10 ± 0.006

0.99 ± 0.043

 Urea, mmol/L

0.76 ± 0.041

0.52 ± 0.041

1.03 ± 0.099

0.80 ± 0.033

0.48 ± 0.042

1.01 ± 0.082

Liver function/hepatic damage

 AST, U/L

0.53 ± 0.085

13.53 ± 1.274

1.04 ± 0.174

0.63 ± 0.05

12.71 ± 0.539

1.01 ± 0.082

 GGT, U/L

0.63 ± 0.063

4.12 ± 0.511

1.04 ± 0.130

0.65 ± 0.073

3.95 ± 0.350

1.01 ± 0.072

 PON, U/mL

0.66 ± 0.031

11.59 ± 0.976

1.02 ± 0.105

0.69 ± 0.025

11.05 ± 0.471

0.99 ± 0.083

Oxidative stress metabolites

 ROMt, mgH₂O₂/100 mL

0.79 ± 0.059

1.51 ± 0.326

1.04 ± 0.095

0.82 ± 0.034

1.30 ± 0.090

1.01 ± 0.052

 AOPP, µmol/L

0.68 ± 0.052

5.36 ± 0.439

1.03 ± 0.136

0.71 ± 0.043

4.92 ± 0.340

0.99 ± 0.092

 FRAP, µmol/L

0.53 ± 0.053

24.86 ± 1.524

1.05 ± 0.173

0.58 ± 0.049

20.57 ± 1.158

0.98 ± 0.098

Inflammation/innate immunity

 Ceruloplasmin, µmol/L

0.77 ± 0.048

0.32 ± 0.049

1.02 ± 0.089

0.82 ± 0.027

0.28 ± 0.018

0.99 ± 0.073

 PROTt, g/L

0.85 ± 0.029

1.90 ± 0.191

1.03 ± 0.079

0.88 ± 0.024

1.58 ± 0.106

1.02 ± 0.052

 Globulins, g/L

0.89 ± 0.019

1.82 ± 0.186

1.02 ± 0.078

0.92 ± 0.023

1.68 ± 0.133

1.01 ± 0.033

Minerals

 Calcium, mmol/L

0.61 ± 0.063

0.07 ± 0.006

1.05 ± 0.132

0.67 ± 0.032

0.05 ± 0.005

1.03 ± 0.098

 Potassium, mmol/L

0.67 ± 0.055

0.24 ± 0.015

1.03 ± 0.102

0.72 ± 0.027

0.21 ± 0.015

1.02 ± 0.082

 Zinc, µmol/L

0.63 ± 0.032

1.54 ± 0.054

1.04 ± 0.222

0.70 ± 0.033

1.44 ± 0.057

0.98 ± 0.095