Ovarian stimulation of Nelore calves and prepubertal heifers with a long-acting recombinant human FSH (corifollitropin-alpha) and subsequent ovum pick-up and in vitro embryo production outcomes.

The aim of this study was to evaluate the use of a long-acting recombinant human FSH (rhFSH, corifollitropin-alpha) to induce ovarian stimulation in Nelore breed (Bos indicus) calves and prepubertal heifers prior to ovum pick-up (OPU) for in vitro embryo production (IVEP). In Experiment 1, a dose-response trial was performed to determine the optimal dose of rhFSH, which was determined to be 10 μg. In Experiment 2, 6-7 mo old calves were randomly allocated to receive rhFSH either via sc (n = 5) or im (n = 5).

Oocyte developmental potential and embryo production before puberty in cattle.

With the development of technologies, embryos can be produced using oocytes retrieved directly from the ovaries, i.e., regardless of ovulation.

Superovulating cattle with corifollitropin-alpha, a long-acting recombinant human FSH (rhFSH): Dose-response, half-life, effects on the ovaries, and embryo outcomes.

The aim of this study was to evaluate the superestimulatory and superovulatory responses of cattle treated with corifollitropin-alpha, a long-acting human recombinant FSH (rhFSH). In the first and second experiments, we used Nelore (Bos indicus) heifers previously submitted to follicular wave suppression by active immunization against GnRH. In Experiment 1 (a dose-response study), heifers (n = 20) were randomly allocated into five groups, which received placebo (saline) or a single sc dose of 7.

Evaluation of the effects of the recommended oral dose of diflubenzuron on bovine sperm and oocyte quality using CASA and OPU-IVEP.

Introduction: The aim of this study was to evaluate potential effects of diflubenzuron on the production and quality of gametes, and on embryo production (IVEP) outcomes, in cattle.

Methods: Two experiments were performed, the first to evaluate effects on semen, and the second on -oocyte complexes (COC) and on IVEP. Nelore () bulls ( = 14) or heifers ( = 16) were allocated into control (CG) or treatment (DIF) groups.

Dynamics of the Reproductive Changes and Acquisition of Oocyte Competence in Nelore (Bos taurus indicus) Calves during the Early and Intermediate Prepubertal Periods.

The purpose of this study was to characterize the reproductive physiology, oocyte competence, and chromatin compaction in Nelore calves in the early-prepubertal period (EPP) and the intermediate-prepubertal period (IPP). Calves aged 2-5 (EPP) and 8-11 months old (IPP) were assigned to Trial 1 (morpho-physiological-endocrine evaluations, n = 8) or Trial 2 (oocyte donors, n = 8) vs. the respective control groups of cows (n = 8, each).

Low levels of sulfur and cobalt during the pre- and periconceptional periods affect the oocyte yield of donors and the DNA methylome of preimplantation bovine embryos.

Maternal nutrition is critical in mammalian development, influencing the epigenetic reprogramming of gametes, embryos, and fetal programming. We evaluated the effects of different levels of sulfur (S) and cobalt (Co) in the maternal diet throughout the pre- and periconceptional periods on the biochemical and reproductive parameters of the donors and the DNA methylome of the progeny in Bos indicus cattle. The low-S/Co group differed from the control with respect to homocysteine, folic acid, B12, insulin growth factor 1, and glucose.

Hormonal stimulation in 4 to 7 months old Nelore (Bos taurus indicus) females improved ovarian follicular responses but not the in vitro embryo production.

The inclusion of pre-pubertal bovine females in reproductive management could allow in vitro embryo production and reduce generation interval, thereby causing faster genetic gain of the herd. However, oocytes of pre-pubertal females have lower competence, blastocyst production, and pregnancy rates than those collected from pubertal animals. This study aimed to evaluate the effect of an induced hormonal stimulation on the serum concentrations of Anti-Mullerian hormone (AMH) and FSH, ovarian responses, ovum pick up (OPU), and in vitro produced embryos (IVP) from oocytes obtained from four-to seven-months old Nelore female cattle.