Neonatal maturity depends on the maternal capacity to provide nutrients for fetal growth. This study aimed to investigate the effects of systemic administration of recombinant porcine somatotropin (pST), one of the main regulators of growth and metabolism, to pregnant gilts during late gestation on circulating nutrients and expression levels of genes in liver and skeletal muscle of their 110-day old fetuses. Gilts received either daily injections of sterile water (control [CTL] group, n = 15) or of 5 mg of pST (pST group, n = 17) from days 90 to 109 of gestation. At day 110 postconceptus, pairs of fetuses (one of small and one of average size within a litter) were selected. Circulating fructose concentrations were greater but circulating concentrations of urea were lower in pST than in CTL fetuses. Expression levels of genes involved in carbohydrate and lipid metabolism were more affected by pST treatment in liver than in muscle. Hepatic molecular changes suggest an inhibition of energy-consuming processes (glycogen and lipid biosynthesis) and the activation of energy-producing pathway (mitochondrial oxidation) in pST compared to CTL fetuses. Expression levels of some genes involved in intracellular degradation of proteins were greater in the liver of pST fetuses, and combined with lower uremia, this suggests a higher utilization of protein sources in pST fetuses than in CTL fetuses. In muscle, molecular changes were mainly observed in the IGF-insulin axis. Altogether, pST-treated gilts seem to have a greater ability to support fetal liver development by the reorientation of energy and protein metabolism.