title: 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.
authors: a Institute of Animal Nutrition and Nutrition Physiology , Justus-Liebig-Universität Giessen , Giessen , Germany.
authors: Denise K
authors: DK
authors: Gessner
authors: Birthe
authors: B
authors: Gröne
authors: Susann
authors: S
authors: Rosenbaum
authors: Erika
authors: E
authors: Most
authors: Sonja
authors: S
authors: Hillen
authors: Sabrina
authors: S
authors: Becker
authors: Georg
authors: G
authors: Erhardt
authors: Gerald
authors: G
authors: Reiner
authors: Robert
authors: R
authors: Ringseis
authors: Klaus
authors: K
authors: Eder
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D004032:Diet / Q000662:veterinary; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D007774:Lactation; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008892:Milk; D047493:PPAR alpha / Q000235:genetics / Q000378:metabolism; D011897:Random Allocation; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics / Q000378:metabolism; D051782:Sterol Regulatory Element Binding Protein 2 / Q000235:genetics / Q000378:metabolism; D034421:Sus scrofa / Q000235:genetics / Q000254:growth & development / Q000502:physiology*
chemical_list: D047493:PPAR alpha; D051780:Sterol Regulatory Element Binding Protein 1; D051782:Sterol Regulatory Element Binding Protein 2
keywords: energy balance; gene expression; lipid metabolism; litter performance; sow lactation; underfeeding