Prepartum fatty acid supplementation in sheep. III. Effect of eicosapentaenoic acid and docosahexaenoic acid during finishing on performance, hypothalamus gene expression, and muscle fatty acids composition in lambs1

Abstract

The objectives of this study were to evaluate the effect of feeding an enriched diet with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to finishing lambs born from ewes supplemented either with or without EPA and DHA during late gestation on productive performance, muscle fatty acid (FA), and hypothalamus mRNA concentration of metabolic genes and hormone receptors. Lambs born from dams fed during the last 50 d of gestation either with a control diet containing 0.39% Ca salts of palmitic fatty acid distillate (C) or Ca salts enriched with EPA and DHA (PFA) were used. After weaning lambs (n = 70) were blocked by weight (BW) and used in a 2 × 2 factorial into 2 finishing diets containing 1.5% of C or PFA. The 2 factors were the ewe diet and the finishing diet. Lambs (37.9 ± 0.4 kg) were weighed and blood sampled for glucose and NEFA measurements at days 1, 14, 28, and 42. Dry matter intake (DMI) was measured daily. At day 43, 14 females and 14 males were slaughtered, and hot carcass weight, body wall thickness, rib eye area, and FA composition of Longissumus thoracis muscle were evaluated. Female hypothalamuses were obtained and mRNA concentration of hormone receptors, neuropeptides, and their receptors was measured. Lambs born from PFA dams were heavier (P < 0.01). There was a time × finishing diet interaction for BW (P = 0.03), and lambs fed C had a greater BW. Lambs fed C had an increase in DMI (P < 0.01). There were no significant differences in plasma glucose and NEFA concentration (P > 0.1). Lambs born from PFA dams had a greater concentration of C22:0 (P < 0.03). Lambs fed C had higher concentrations of C18:1c15 (P < 0.01), C17:0 (P < 0.09), C18:0 (P < 0.09), and n6/n3 (P < 0.01). Lambs fed PFA had greater concentration (P < 0.05) of C16:1, C22:1, C20:5, C22:5, C22:6, total n3 FA, and total EPA and DHA. There was a significant dam × finishing diet interaction (P ≤ 0.08) on mRNA concentration for MCR3, CCK-R, Cort-R, and CART. Lambs, which had the same treatment as their dams, showed lower overall mRNA concentration than those with different treatments between them and their dams. Lambs born from PFA ewes had lower concentration of MCR4 mRNA (P = 0.09) than C. Agouti-related peptides mRNA concentration was lower in lambs fed PFA (P = 0.06) than C. In conclusion, changes on lamb performance, muscle fatty acid composition, and metabolic neuropeptides depend not only on the lamb diet, but also on the dam diet during late gestation.

Effects of maternal dietary omega-3 polyunsaturated fatty acids and methionine during late gestation on fetal growth, DNA methylation, and mRNA relative expression of genes associated with the inflammatory response, lipid metabolism and DNA methylation in placenta and offspring’s liver in sheep

“…Jones et al [ 10 ] reported an increased in fetal and placental growth after omega-3 PUFA supplementation during late gestation in rats. In accordance with Jones et al [ 10 ], Carranza Martin et al [ 28 ] reported an increase in birth BW in lambs born from dams supplemented with 0.39% Ca salts of n-3 PUFA during the last 50 days of gestation. Likewise, a heavier birth weight was associated with in late gestation RPM supplementation in Holstein cows, suggesting that maternal supply of Met during late pregnancy enhanced in utero growth [ 47 , 48 ].…”

“…Supplementation with omega-3 PUFA or Met has beneficial effects on development and growth of the offspring, and supplementation with one or the other has showed to modify the expression of immune mediators, enzymes involved in DNA methylation, and increased growth, but the effects of supplementation with both nutrients on fetus growth, gene expression of cytokines in the NF-κB pathway, enzymes present in the methionine cycle, DNA methylation, and in the RvD1 omega-3 PUFA metabolic pathway, as well as on global DNA methylation of fetal tissues, have not been studied. According to previous studies [ 4 , 11 , 28 ], we expect that fetus growth from dams supplemented with these two nutrients will be associated with an increase in the mRNA expression of the enzymes that participates in DNA methylation (DNMT), Met cycle, and RvD1 metabolic pathway after PUFA supplementation. We assume that PUFA supplementation would modified the expression of DNMT enzymes and Met supplementation will increase methyl donors, thus increasing DNA methylation.…”

“…According to the available literature [ 10 , 28 , 47 , 48 ], we expected a greater increase in the fetal, placental, and FL weights of fetus from ewes that were fed both nutrients, despite inconsistencies observed in results after FA supplementation in late gestation [ 3 , 9 , 28 , 46 ]. Jones et al [ 10 ] reported an increased in fetal and placental growth after omega-3 PUFA supplementation during late gestation in rats.…”

“…Table 1 contains the dietary ingredients and chemical composition of the basal diet while Table 2 contains the FA profile of the supplement used. The dose of omega-3 PUFA was based on previous research in pregnant ewes where supplementation at similar doses had effects on lamb growth, and abundances of relevant mRNA transcripts in the adipose tissue of ewe without affecting dam performance [ 3 , 27 , 28 ]. In these two previous studies [ 27 , 28 ] an intake of at least 18 mg/kg of metabolic BW (BW 0.75 ) of EPA and DHA was aimed.…”

“…The dose of omega-3 PUFA was based on previous research in pregnant ewes where supplementation at similar doses had effects on lamb growth, and abundances of relevant mRNA transcripts in the adipose tissue of ewe without affecting dam performance [ 3 , 27 , 28 ]. In these two previous studies [ 27 , 28 ] an intake of at least 18 mg/kg of metabolic BW (BW 0.75 ) of EPA and DHA was aimed. The targeted dose was based on research conducted in humans [ 29 ] where supplementation with EPA and DHA at this dose improved insulin sensitivity and decreased cardiovascular disease risk.…”