Effects of a n-3 polyunsaturated fatty acid-enriched diet on embryo production in dairy cows

Abstract

Beneficial effects of n-3 polyunsaturated fatty acid (PUFA) supplementation on dairy cow reproduction have been previously reported. The objectives of the present study were to assess whether n-3 PUFA supplementation would affect in vitro embryo production (IVP) after ovarian stimulation. Holstein cows received a diet with 1% dry matter supplementation of either n-3 PUFA (n = 18, microencapsulated fish oil) or a control, n-6 PUFA (n = 19, microencapsulated soy oil). Both plasma and follicular fluid FA composition showed integration of total PUFA through the diet. All cows underwent an IVP protocol consisting of ovarian stimulation, ultrasound-guided transvaginal oocyte retrieval (ovum pick-up, OPU, five per cow) followed by in vitro maturation, fertilisation and 7 days of embryo development. A tendency toward an increase in the blastocyst rate (diet effect, P = 0.0865) was observed in n-3 cows, with 49.6 ± 5.5% vs 42.3 ± 5.5% in control n-6 cows. A significant increase (diet effect, P = 0.0217) in the good-quality blastocyst rate (freezable blastocysts) was reported in n-3 cows (42.2 ± 7.7%) compared to control n-6 cows (32.7 ± 7.7%). A significant difference in lipid composition was shown in the oocytes recovered by OPU from n-3 and n-6 treated cows, by intact single-oocyte MALDI-TOF mass spectrometry. The 42 differentially abundant identified lipids were mainly involved in cell membrane structure. In conclusion, n-3 PUFA supplementation enhanced oocyte quality and modified their lipid composition. Further studies are necessary to investigate the potential link of these lipid modifications with enhanced oocyte quality.

A Comparative Analysis of Oocyte Development in Mammals

“…The number of lipid droplets in the oocyte can correlate with its cytoplasmic maturation status and, therefore, with its competence to support embryo development [199,220]. Moreover, a dietary supplementation in n-3 PUFA, as mentioned in the previous paragraph, is able to modulate the lipid composition of bovine oocytes [210]. Such modifications of oocyte lipid composition are also reported after in vitro supplementation of n-3 PUFA during maturation in the bovine [215] or of conjugated linoleic acid in the porcine [221].…”

“…A PUFA, namely oleic acid, could restore the quality of bovine oocyte that had been previously exposed to high levels of saturated fatty acids, partly through an increase in the amount of lipids stored in lipid droplets of cumulus cells [209]. In bovine, n-3 PUFA supplementation increases gestation rate and the cryotolerance of in vitro produced embryos, and reduces early embryo mortality in vivo [209][210][211]. Such dietary supplementation has also been reported to potentially enhance oocyte quality in the ewe [212], whereas it can be detrimental in the mouse [213].…”

MALDI-TOF Mass Spectrometry Revealed Significant Lipid Variations in Follicular Fluid and Somatic Follicular Cells but Not in Enclosed Oocytes between the Large Dominant and Small Subordinate Follicles in Bovine Ovary

“…However, accumulation of lipids in the oocytes correlates with their competence to in vitro embryo development [ 25 , 26 ]. In cows, lipid composition of COC environment affected oocyte quality, in vitro and in vivo [ 27 , 28 , 29 ]. FF of cows, which have received the diet supplementation with 1% dry matter of polyunsaturated FA n -3, was significantly enriched in n -3 PUFA, and correspondent enclosed oocytes have developed higher quality blastocysts compared to control animals [ 29 ].…”

“…In cows, lipid composition of COC environment affected oocyte quality, in vitro and in vivo [ 27 , 28 , 29 ]. FF of cows, which have received the diet supplementation with 1% dry matter of polyunsaturated FA n -3, was significantly enriched in n -3 PUFA, and correspondent enclosed oocytes have developed higher quality blastocysts compared to control animals [ 29 ]. In addition, supplementation of 1 μM of n -3 PUFA docosahexaenoic acid during in vitro maturation of bovine oocytes resulted in their higher blastocyst rate after in vitro fertilization [ 27 ].…”

“…In addition, supplementation of 1 μM of n -3 PUFA docosahexaenoic acid during in vitro maturation of bovine oocytes resulted in their higher blastocyst rate after in vitro fertilization [ 27 ]. Moreover, lipid composition of PUFA n -3 treated oocytes in vivo and in vitro significantly differed compared to control ones [ 28 , 29 ].…”