Effect of a negative energy balance induced by feed restriction in lactating sows on hepatic lipid metabolism, milk production and development of litters

Abstract

In rodents, forced activation of hepatic peroxisome proliferator-activated receptor α (PPARα) by administration of exogenous PPARα activators during lactation leads to a reduction of milk triacylglycerol (TAG) production. Herein, we investigated whether a negative energy balance (NEB) induced by feed restriction (about 18% lower feed and energy intake) during lactation by increasing the release of fatty acids, which act as PPARα agonists, causes a disruption of hepatic lipid metabolism and thereby impairs milk TAG production in sows. Nutrient and energy content of the milk on day 20 of lactation and gains of litters during the first 14 d and the whole 21 d suckling period did not differ between Control and feed-restricted sows. The mRNA concentrations of several sterol regulatory element-binding protein target genes involved in lipid synthesis in the liver and the plasma concentration of TAG were reduced in the feed-restricted sows, whereas the mRNA concentrations of PPARα target genes involved in fatty acid oxidation in liver and skeletal muscle were not different between groups. In conclusion, it was shown that an NEB during lactation does not adversely affect milk composition and gains of litters, despite inhibiting hepatic expression of genes involved in lipid synthesis and reducing plasma TAG concentration. The finding that PPARα target genes involved in fatty acid utilisation in liver and muscle of sows are not induced by the NEB during lactation may explain that fatty acid availability in the mammary gland is sufficient to maintain milk TAG production and to allow normal litter gain.

Effects of dietary resveratrol supplementation during gestation and lactation of sows on milk composition of sows and fat metabolism of sucking piglets

“…It may be due to the role of resveratrol in energy metabolism. Resveratrol, a natural compound, has been reported to affect energy metabolism and mitochondrial function and to serve as a calorie restriction mimetic (Gessner et al, ). In addition, previous studies have reported that resveratrol supplementation reduced liver fat accumulation and increased rates of fatty acid oxidation and promoted the release of energy (Forouzan, Azita, & Payman, ).…”

“…It may be due to the role of resveratrol in energy metabolism. Resveratrol, a natural compound, has been reported to affect energy metabolism and mitochondrial function and to serve as a calorie restriction mimetic (Gessner et al, 2015).…”

Impacts of Macronutrients on Gene Expression: Recent Evidence to Understand Productive and Reproductive Performance of Livestock

“…Using bovine mammary epithelial cells (BMEC) in vitro, Liu et al, showed that increasing glucose availability may increase the synthesis of milk fat and lactose by modulating the mRNA expression of key genes and subsequently affect the synthesis of milk composition . On the other hand, restriction of macronutrients during lactation results in a decrease of mRNA concentrations of sterol regulatory element-binding protein target genes involved in lipid synthesis in the liver along with plasma concentration of TAG (Gessner et al, 2015) which may regulate the milk production in lactating pigs. Several of milk traits (milk production, acidity, milk stability etc.)…”

Effects of maternal protein restriction during pregnancy and lactation on milk composition and offspring development

“…Maternal milk is widely considered the best feeding source for newborns compared with the alternatives (1)(2)(3) , even in the setting of maternal undernutrition during pregnancy and lactation, which not only affects maternal health but negatively programmes neonatal growth and organ development and maturation (4)(5)(6)(7)(8) . Reduced maternal nutrition is the most extensively studied programming challenge of offspring phenotypic plasticity (9) .…”