Typical examples of metabolites whose concentrations decreased with progressing hepatic lipidosis. Group 1: no hepatic lipidosis; groups 2–4: different stages of hepatic lipidosis (mean values of 5–10 animals). (A) Level of glycine in the serum of dairy cows. (B) Level of glutamine in the serum of dairy cows. The P values indicate significant differences with the reference group 1.