The objective was to determine effects of calf age and physical form of oat grain in calf starter on gene expression of hepatic energy metabolism enzymes in pre-weaned dairy calves. In 3 experiments, either ground or whole oats were used in the calf starter. Seven calves were slaughtered at 5 wk of age in experiment 1; 6 were slaughtered at 6 wk in experiment 2; and 7 in experiment 3 were slaughtered at 7 wk of age. Liver tissue was harvested immediately and stored at −80°C for further processing. Calves from experiment 1 and 2 were cannulated and their rumen pH measured. Liver RNA was extracted by a phenol-chloroform method and reverse transcribed to cDNA. The mRNA expression of gluconeogenic enzymes pyruvate carboxylase (PC), cytosolic and mitochondrial phosphoenolpyruvate carboxykinase (PEPCK-C and PEPCK-M) and fatty acid oxidation enzyme carnitine palmitoyl transferase I (CPT-1) was measured by RT-PCR. The statistical model included fixed effects of experiment and physical form of oats and the geometric mean of normalization genes (β-Actin and GAPDH) as a covariate. The mRNA expression for all enzymes PC, PEPCK-C, PEPCK-M, and CPT-1 was not affected (P > 0.10) by the physical form of oats; however, all enzymes were affected by experiment (P < 0.10). Expression of PC, PEPCK-C, and CPT-1 was greater in experiment 2 than experiment 1 and 3 calves (P ≤ 0.10). Expression of PEPCK-M was greater experiment 2 and 3 than experiment 1 (P < 0.05). For all enzymes, expression differed between experiment 1 and 2 calves. Similarly, rumen pH was also different, with experiment 1 calves averaging 5.69 and experiment 2 calves averaging 4.81 (P < 0.05). Except for PEPCK-M, mRNA expression of all enzymes was similar between experiments 1 and 3. We conclude that the influence of age on liver gluconeogenic and fatty acid oxidation enzyme expression was not consistent and physical form of oats in calf starter did not affect their expression in pre-weaned dairy calves. However, lower rumen pH may be related to the upregulation of these enzymes in experiment 2 calves.