Table 5 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 herd-out cross-validation scenario of blood metabolites parameters using BayesB and gradient boosting machine (GBM) methods

Energy-related metabolites

 Glucose, mmol/L

0.63 ± 0.066

0.26 ± 0.034

1.07 ± 0.040

0.65 ± 0.035

0.16 ± 0.008

1.02 ± 0.073

 BHBA, mmol/L

0.40 ± 0.105

0.21 ± 0.033

0.94 ± 0.068

0.43 ± 0.062

0.12 ± 0.009

0.97 ± 0.057

 Urea, mmol/L

0.47 ± 0.164

0.78 ± 0.119

0.97 ± 0.084

0.49 ± 0.051

0.52 ± 0.041

1.01 ± 0.093

Liver function/hepatic damage

 AST, U/L

0.38 ± 0.115

17.14 ± 2.069

0.97 ± 0.072

0.43 ± 0.085

13.53 ± 1.268

1.05 ± 0.060

 GGT, U/L

0.45 ± 0.080

5.38 ± 0.341

0.98 ± 0.051

0.48 ± 0.063

4.12 ± 0.511

1.03 ± 0.046

 PON, U/mL

0.48 ± 0.035

17.21 ± 0.127

0.99 ± 0.091

0.52 ± 0.081

12.59 ± 1.577

1.02 ± 0.062

Oxidative stress metabolites

 ROMt, mgH₂O₂/100 mL

0.66 ± 0.071

1.89 ± 0.133

0.97 ± 0.089

0.69 ± 0.079

1.51 ± 0.326

1.01 ± 0.056

 AOPP, µmol/L

0.37 ± 0.057

8.86 ± 0.770

0.98 ± 0.076

0.41 ± 0.052

5.36 ± 0.440

1.01 ± 0.073

 FRAP, µmol/L

0.25 ± 0.061

36.86 ± 1.664

0.94 ± 0.082

0.29 ± 0.093

25.85 ± 2.601

1.01 ± 0.097

Inflammation/innate immunity

 Ceruloplasmin, µmol/L

0.58 ± 0.052

0.44 ± 0.004

0.96 ± 0.058

0.62 ± 0.066

0.32 ± 0.050

1.01 ± 0.065

 PROTt, g/L

0.76 ± 0.02

2.57 ± 0.255

0.97 ± 0.021

0.79 ± 0.039

1.91 ± 0.189

0.98 ± 0.050

 Globulins, g/L

0.77 ± 0.011

2.6 ± 0.312

0.96 ± 0.047

0.80 ± 0.019

1.82 ± 0.186

0.97 ± 0.037

Minerals

 Calcium, mmol/L

0.42 ± 0.086

0.17 ± 0.004

1.01 ± 0.093

0.47 ± 0.073

0.07 ± 0.007

0.98 ± 0.099

 Potassium, mmol/L

0.54 ± 0.065

0.32 ± 0.014

0.98 ± 0.094

0.57 ± 0.055

0.24 ± 0.014

1.04 ± 0.093

 Zinc, µmol/L

0.47 ± 0.083

2.27 ± 0.056

1.05 ± 0.099

0.50 ± 0.042

1.54 ± 0.054

1.02 ± 0.095