In vitro embryo production from ewes at different physiological stages

Abstract

Background The collection of ovaries from slaughterhouses is an important source of oocytes for in vitro embryo production. On the other hand, the physiological stage of slaughtered females varies and influences embryo production. Objectives The study examined the in vitro efficiency of embryos and demi-embryos from young, non-pregnant adult, and pregnant adult ewes from a local slaughterhouse. Methods One thousand three hundred ovaries were collected from August to October 2020. The recovered oocytes were matured, fertilized, and cultured at 5% CO 2 , 38.5°C, and 100% humidity. Embryo bisection was performed in 96 blastocysts (n = 32 per treatment). The demi-embryo pairs were incubated for their reconstitution for 12 h. SAS was used for data analysis. Results The number of oocytes collected from the experimental group of non-pregnant adult ewes was higher ( p ≤ 0.007) than those collected from the group of pregnant adult ewes (2.67 ± 0.19 vs. 2.18 ± 0.15 oocytes/group, respectively). The blastocyst rate was higher ( p ≤ 0.0001) in the non-pregnant adult group (36.39%) than in the young (17.96%). The ratio of demi-embryos that recovered the blastocoelic cavity was higher ( p < 0.05) in the young group (81.25%) than in the pregnant adult group (59.38%). The diameter of the demi-embryos was higher ( p < 0.05) in the non-pregnant adult group (186.54 ± 8.70 μm) than those in the young and pregnant adult groups. Conclusions In conclusion, the in vitro embryo production efficiency was highest when using oocytes from non-pregnant adult ewes under the conditions of this study.

Resveratrol Reduces ROS by Increasing GSH in Vitrified Sheep Embryos

“…Hernández et al [47] reported a low number of nuclei (44.2 ± 9.9) present in parthenogenetic blastocysts of O. aries and in interspecies cloned blastocysts of O. aries and Ovis canadensis mexicana (46.7 ± 8.1 nuclei). Lorenzo-Torres et al [48] reported 122 nuclei in good-quality blastocysts produced by IVF. These results are lower than those obtained in the present study, but they are similar to those reported by Agata et al [49], Mastrorocco et al [50], and Nadri et al [51].…”