The human heart starts beating at 21 days gestation and does not stop until death. This posits an incessant metabolic demand that must be met despite abrupt changes to cardiac load, nutritional substrates and oxygenation that occurs at birth. Fetal cardiomyocytes rely on lactate and glucose for ATP production, while healthy adult cardiomyocytes utilize mostly fatty acids. This thesis provides new insights into the normal developmental profile of the myocardial fatty acid metabolic pathway in the perinatal period in a precocial species, and the impact of IUGR on this pathway.