title: Long term vitamin A restriction improves meat quality parameters and modifies gene expression in Iberian pigs.
abstract: Vitamin A is a key regulator of gene expression, influencing adipogenesis and lipid metabolism in animal tissues. This experiment was conducted to assess the effect of dietary vitamin A level and administration time on productive traits, intramuscular fat (IMF) content in ham muscles, tissue fatty acid composition, and expression of a panel of adipogenic and lipogenic candidate genes in Iberian pigs. Sixty piglets of 16.3 kg (SD = 2.5 kg) live weight (LW) were either fed a vitamin A-enriched diet (10,000 IU vitamin A/kg; CONTROL, n = 20) or a diet without supplemented vitamin A, applied from 16.3 kg (SD = 2.5 kg; early restriction group, ER, n = 20) or from an average weight of 35.8 kg (SD = 3.1 kg; late restriction group, LR, n = 20). Two slaughters were performed when pigs reached the averaged weights of 101.4 (SD = 4.1 kg) and 157.9 kg LW (SD = 7 kg) and samples from liver, heart, and backfat were obtained in both sacrifice times. In addition, ham subcutaneous fat and Semimembranosus (SM) and Biceps Femoris (BF) muscles were sampled at the last sacrifice. Dietary vitamin A level produced no effect on carcass traits in any of the harvests, while a small effect was observed on fatty acid composition in backfat at 101.4 kg LW. However, at 157.9 kg LW, the ER and LR groups showed higher MUFA content and lower SFA content in backfat, ham fat, and IMF (P < 0.01). In IMF, a decrease in n-6/n-3 PUFA ratio was observed in the restricted groups (P < 0.005). Intramuscular fat content in SM muscle was greater (P < 0.05) in the ER group than in the CONTROL and LR groups, while no difference was detected in BF muscle. Little effect of dietary vitamin A was observed in liver. Regarding changes in gene expression, ACSL4, CEBPB, and IGF1 genes were upregulated (P < 0.0001, P < 0.0001, and P < 0.05, respectively) in the ER group in hepatic tissue, whereas CRABPII and SCD genes were upregulated (P < 0.05) in the same group in adipose tissue. On the other hand, was downregulated ( < 0.05) in the ER group in adipose tissue. Results found in this experiment show that long-term restriction of dietary vitamin A has a positive effect on nutritional and sensorial parameters of ham meat. Moreover, gene expression results were consistent with the vitamin A transcriptional regulation of adipogenesis and lipogenesis and with the changes observed in meat and fat composition.
authors.forename: M
authors.initials: M
authors.lastname: Ayuso
authors.forename: A
authors.initials: A
authors.lastname: Fernández
authors.forename: B
authors.initials: B
authors.lastname: Isabel
authors.forename: A
authors.initials: A
authors.lastname: Rey
authors.forename: R
authors.initials: R
authors.lastname: Benítez
authors.forename: A
authors.initials: A
authors.lastname: Daza
authors.forename: C J
authors.initials: CJ
authors.lastname: López-Bote
authors.forename: C
authors.initials: C
authors.lastname: Óvilo
mesh_terms: D050156:Adipogenesis / Q000187:drug effects; D000818:Animals; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000378:metabolism; D003066:Coenzyme A Ligases / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005527:Food, Fortified; D020869:Gene Expression Profiling / Q000662:veterinary; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008460:Meat / Q000032:analysis / Q000592:standards*; D018482:Muscle, Skeletal / Q000254:growth & development; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D050151:Subcutaneous Fat / Q000378:metabolism; D034421:Sus scrofa / Q000378:metabolism / Q000502:physiology*; D013552:Swine; D014801:Vitamin A / Q000008:administration & dosage / Q000494:pharmacology*; D000098859:Long-Chain-Fatty-Acid-CoA Ligase
chemical_list: D022782:CCAAT-Enhancer-Binding Protein-beta; D005227:Fatty Acids; D018168:Receptors, Retinoic Acid; C082928:retinoic acid binding protein II, cellular; D014801:Vitamin A; D007334:Insulin-Like Growth Factor I; D003066:Coenzyme A Ligases; D000098859:Long-Chain-Fatty-Acid-CoA Ligase