Production of sexed bovine embryos in vitro can be improved by selection of sperm treatment and co-culture system.

The study investigated the effects of sperm sorting, capacitation treatment and co-cultivation on sexed bovine in vitro embryo production. The effect of treatment and co-culture on production of embryos of the preferred sex from unsorted sperm was also studied. Sperm from five breeding bulls was used for fertilization of mature oocytes as follows: Experiment 1, sorted and unsorted sperm (bulls A-E) treated only with heparin in standard co-cultures; Experiment 2, sorted sperm (bulls A-E) treated with heparin-PHE (penicillamine, hypotaurine, and epinephrine) or heparin-caffeine in drop co-cultures; and Experiment 3, unsorted sperm (bull E) treated with either heparin-PHE or heparin-caffeine in both standard and drop co-cultures.

Expression of selected mitochondrial genes during in vitro maturation of bovine oocytes related to their meiotic competence.

The main goal of this study was to characterize the expression patterns of genes which play a role in mitochondrial DNA biogenesis and metabolism during the maturation of bovine oocytes with different meiotic competence and health. Meiotically more and less competent oocytes were obtained separately either from medium (MF) or small (SF) follicles and categorized according to oocyte morphology into healthy and light-atretic. The four oocyte categories were matured and collected after 0, 3, 7, 16 and 24 h of maturation.

Supplementation of l-carnitine during in vitro maturation improves embryo development from less competent bovine oocytes.

The present study was designed to define the impact of l-carnitine, supplemented during maturation, on bovine oocytes with different meiotic competence in terms of their IVF outcomes. Meiotically more competent (MMC) and less competent (MLC) oocytes were obtained separately from differently sized follicles at selected phases of folliculogenesis. The oocytes were matured with or without l-carnitine, fertilized and cultured to the blastocyst stage.

Aneuploidy Detection and mtDNA Quantification in Bovine Embryos with Different Cleavage Onset Using a Next-Generation Sequencing-Based Protocol.

Bovine embryos are now routinely used in agricultural systems as a means of disseminating superior genetics worldwide, ultimately with the aim of feeding an ever-growing population. Further investigations, common for human IVF embryos, thus have priority to improve cattle IVF, as has screening for aneuploidy (abnormal chromosome number). Although the incidence and consequences of aneuploidy are well documented in human preimplantation embryos, they are less well known for the embryos of other animals.

Energy Status Characteristics of Porcine Oocytes During In Vitro Maturation is Influenced by Their Meiotic Competence.

The characteristics of energy status in porcine oocytes as related to their meiotic competence and in vitro maturation were studied. Cycling pubertal gilts in the early luteal to early follicular phases of the ovarian cycle were used as oocyte donors. The oocytes recovered from medium (MF) or small follicles (SF) were considered meiotically more or less competent, respectively.