Hepatic Fatty Acid Oxidation and Ketogenesis in Young Pigs

       A primary limitation to efficient pork production is morbidity and mortality during the perinatal period. Because pigs are born with low energy reserves, their survival hinges on timely consumption of milk. In contrast to carbohydrate-based fetal metabolism, the transition to a milk-based diet necessitates rapid biochemical adaptations to accommodate the oxidation of fatty acids which comprise more than 60% of milk energy. From research reported to date, the degree to which neonatal pigs make these adaptations is questionable. In stark contrast to other mammalian neonates, piglets do not demonstrate elevated ketogenesis despite high milk-fat intake. Ketone bodies play a pivotal role in the transition from carbohydrate-based metabolism to fat-based metabolism, providing an important alternative fuel for glucose-dependent tissues. Impaired adaptation limits the piglets' ability to oxidize fat which likely contributes to the etiology of mortality. Therefore, it is imperative to understand the developmental aspects of lipid oxidation in the young pig. With the key regulatory enzymes previously elucidated in rodents as a starting point, we are investigating regulation in the pig. Further research in this area will hopefully assist in development of strategies (via nutritional and/or exogenous hormonal manipulation) to enhance development of fatty acid oxidation and ultimately improve piglet survival and growth.