Influence of different environments on oocyte maturation and development of bovine embryos in vitro

Abstract

According to the International Embryo Technology Society, the number of bovine embryos produced by in vitro fertilization technology is increasing every year. However, despite the large volumes of their production, the effectiveness of this method is still low and needs to be improved. Therefore, the purpose of this study was to compare the effectiveness of two commercial media – Origio Sequential Series (Origio, Denmark) and a panel of products manufactured by Minitube (Germany) in terms of oocyte maturation and development of bovine embryos in vitro. At the first stage of the study, a comparative evaluation of oocyte maturation media was performed: based on TCM 199 (Minitube) and Universal (Origio) culture media. At the second stage, the protocols for culturing bovine embryos were compared: Minitube and the two-stage Origio culture protocol with changing media. Therewith, it was found that the use of TCM 199 medium for oocyte maturation is more effective compared to Universal. Thus, at 48 hours of cultivation (the initial stage of embryo development), 64.3 ± 1.0 and 60.3 ± 1.4% of 2-8 cell embryos were obtained, and on Day 8 – 25.3 ± 1.0 and 20.0 ± 0.6% of blastocysts, respectively. The results of a comparison of bovine embryo culture protocols showed that when using both Minitube and Origio media, the percentage of division and the percentage of resulting embryos corresponded to their known values. It was found that the Minitube cultivation protocol is more effective than Origio. At 48 hours, the number of embryos obtained using the Minitube culture protocol was 1.3% higher compared to Origio, on Day 6 – by 7.8%, and on Day 8 – by 3.8%. The results obtained are a necessary component of the development of successful processes to produce bovine embryos in vitro with further implementation in the ruminant reproduction biotechnology

Development of alternative diagnosis of HH1, HH3, HH5 and HCD fertility haplotypes and subfertility syndrome in cattle

“…Moreover, another study shed light on the genetic landscape of Holstein cattle, reporting even higher percentages of heterozygous carriers of fertility haplotypes. From the DNA analysis of the tested animals, 27.43% were identified as heterozygous carriers of one fertility haplotype, 2.27% simultaneously carried two defects, and a small fraction, 0.12%, exhibited three genetic anomalies(Khan et al, 2021;Kovpak et al, 2022) Id-Lahoucine et al (2023). investigated transmission ratio distortion (TRD) in the bovine genome and identified candidate regions associated with reproduction defects.…”