Metabolic and molecular responses to calcium soap of fish oil fed to ewes during peripartal period

Abstract

It has been shown that n-3 long chain fatty acids (n-3 LCFA) are involved in energy/lipid metabolisms, reproductive parameters, and molecular regulations leading to maintained homeostasis. We hypothesized that supplementation of peripartal diets with fish oil (FO), as a source of n-3 LCFA, could improve energy balance and modulate metabolic pressure in a sheep model. Prepartum ewes (n = 24) were fed control (CON) or calcium soap of fish oil (FO) supplemented-diet from four weeks before until three weeks after parturation. Feed intake, body weight (BW) change, plasma metabolites, colostrums/milk composition, and fatty acids profile of milk along with the expression of core microRNAs in glucose and lipid metabolism were evaluated. Prepartal feed intake decreased in FO group (1674 ± 33.26 vs. 1812 ± 35.56) though post-partal intake was similar. Differences in BW were not also significant (55.47 ± 2.07 in CON vs. 53.69 ± 1.94 in FO). No differences were observed in plasma metabolites except for cholesterol that was lower in FO group (56.25 ± 0.71 vs. 53.09 ± 0.61). Milk fat percentage was reduced (8.82 ± 0.49 vs. 7.03 ± 0.45) while the percentage of milk total n-3 LCFA increased in FO group. In accordance, the relative transcript abundance of miR-101 (0.215 ± 0.08) and miR-103 (0.37 ± 0.15) decreased by FO supplementation. Results showed that FO supplementation during peripartal period decreased milk fat, feed intake, plasma cholesterol, milk n-6:n-3 ratio and the expression of miR-101. Although the trend indicated that FO could alter lipid metabolism during transition period, further studies are needed to fully address its effect on energy balance and homeorhetic processes.

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

“…However, ewes in the NS and the FS-MS showed an unexpected increase in BW. Our results differ with the ones reported by Sheibani et al [ 43 ], and two other previous studies [ 3 , 27 ] where feeding different sources of omega-3 PUFA during the last third of gestation did not show differences in ewe prepartum BW or BCS. Likewise, Waterman et al [ 44 ] and Osorio et al [ 45 ] did not report any differences in BW or BCS when RPM was fed during late gestation.…”

“…Likewise, Waterman et al [ 44 ] and Osorio et al [ 45 ] did not report any differences in BW or BCS when RPM was fed during late gestation. The inconsistent results reported in the current experiment with the ones aforementioned [ 3 , 27 , 43 – 45 ] might have been related to the interaction between omega-3 PUFA and Met, or to differences in the amount fed, as well as in the type of omega-3 PUFA and Met supplementation, and the length of feeding. We could not establish any physiological explanation for the current findings on dam performance when PUFA and Met were supplemented in late gestation, since no differences in DMI were observed, or any association between ewe’s performance and plasma metabolites of NS or FS-MS was established.…”