Effects of maternal nutrition during gestation in ruminant maternal and fetal and offspring viscera energy use and hypothalamic neurohormone content in the offspring

Abstract Text:

The extensive use of grazing systems for ruminant livestock and the high variation in forage quality throughout the year have important impacts on production. Changes in feed quality and availability cause alteration in the nutritional and physiological status of gestating animals. Modifications of the maternal nutritional environment throughout fetal development can have an impact on later performance of the offspring. Adjustments in the maternal metabolism have been correlated with an increase in maternal energy use during pregnancy, and also further adjustments that occur in the dam’s metabolism to provide adequate oxygen (O₂), nutrients, and energy reserves for fetal growth and maternal maintenance systems. Moreover, energy utilized by fetal visceral tissues can be altered in response to changes in maternal feed intake. Prolonged changes in maternal feed intake during early pregnancy, the time which fetal brain development is taking place, can result in up- and/or down-regulation of neurohormones that play an important role in controlling how energy utilization and feed intake of these offspring will occur later in life. We designed three different studies with the main objective to investigate how maternal nutrient restriction throughout gestation or during different periods of gestation affects visceral organs metabolism in the dam and in the fetus. Furthermore, to understand the effects of developing in an IUGR environment might have on postnatal liver and small intestine mass and energy use and on the protein content of neurohormones that control feed intake and energy metabolism, from specific nuclei of the hypothalamus. Our results indicated that, maternal hepatic and jejunal mass and energy use are impacted by nutrient restriction; however they can be altered by realimentation strategically offered during different stages of gestation. The same impacts are observed in fetal visceral development and metabolism and in liver energy use in postnatal life. Moreover, arginine supplementation appears to be a nutritional strategy that diminishes the possible deleterious effects in maternal and fetal visceral metabolism in response to nutrient restriction. Finally, maternal nutrient restriction throughout gestation caused decreased number of cells in the hypothalamus of the offspring that express POMC protein perhaps influencing energy metabolism in the offspring.

Keywords: viscera, energy use, neuropeptide