Dietary rumen-protected polyunsaturated fatty acids (PUFAs) rich in linoleic acid (LA) may affect embryo yield, and LA can modulate the molecular mechanisms of lipid uptake in bovine blastocysts produced in vitro. In embryos, membrane lipids, such as phosphatidylcholines (PCs) and sphingomyelins (SMs), affect cryopreservation success. The aim of the present study was to evaluate embryonic developmental rates after the IVF of oocytes retrieved from Nellore heifers fed for approximately 90 days with rumen-protected PUFAs rich in LA. In addition, we evaluated embryo cryotolerance and the membrane structure lipid composition using matrix-assisted laser desorption ionisation mass spectrometry of fresh and vitrified embryos. Embryo development to the blastocyst stage (mean 43.2%) and embryo survival after vitrification and warming (mean 79.3%) were unaffected by diet. The relative abundance of one lipid species (PC ether (PCe; 38:2, which means that this lipid has 38 carbon atoms and 2 double bonds in the fatty acyl residues) was increased after PUFAs supplementation. However, 10 ions were affected by cryopreservation; ions consistent with PC 32:0, PC 34:1, SM 24:1, PC 40:6 or PC 42:9, PC plasmalogen (PCp) 44:10 or PC 42:7, triacylglycerol (TAG) 54:9 and a not assigned ion (m/z 833.2) were lower in blastocysts that survived to the cryopreservation process compared with fresh blastocysts, whereas the abundance of the ions PC 36:3 or PC 34:0, PCe 38:2 or PC 36:6 and PC 36:5 or PCe 38:1 were increased after cryopreservation. Thus, the results demonstrate that the mass spectrometry profiles of PC, SM and TAG species differ significantly in bovine blastocysts upon cryopreservation. Because the lipid ion abundances of fresh and vitrified-warmed embryos were distinct, they can be used as potential markers of post-cryopreservation embryonic survival.
We evaluated the effect of supplementation with MGA incorporated into nutritional blocks on pregnancy rates (PR) after natural mating and AI of heifers and primiparous cows (Nellore) raised in extensive management. In exp 1, 413 heifers were grouped: control; Block-EB-P4; Block-MGA ; and Bran-MGA, and animals submitted to natural mating. In exp 2, 301 heifers were grouped: control; Block-MGA; and Block-MGA-EC, with animals inseminated after estrus observation for 10 days and, afterwards, mated with bulls. In exp 3, 342 primiparous cows, were divided into 4 groups: Control, Block-MGA-EB-eCG;Block-MGA-EB-CalfRemoval and Block- MGA-CalfRemoval, next, cows were mated with bulls. In exp 1, PR at beggining of breeding season was higher in the Block-MGA (57.84%; P < 0.01) in relation to Control (40.8%) and Block-BE-P4 (36.4%) and it was similar to Bran-MGA (51.0%). In experiment 2, PR at beggining of the BS in the control (56.6%; P = 0.04) was lower than in the MGA-EC (74.4%) and similar to the MGA group (67.7%). In exp 3, at 70 days (P = 0.01) and at the end of the BS( P < 0.02), respectively, the control (55%; 60.4%) had a lower PR than the groups MGA-EB-eCG (72.3%;75.9%;), MGA-EB-CR (74.1%;82.7%) and MGA-CR (74.4%; 81.3%). The results showed that use of MGA added to nutritional blocks in primiparous and heifers provided higher pregnancy rates at the beginning of the breeding season, and also higher PR in primiparous at the end of the season, representing an alternative for reproductive management under extensive conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.