Effects of calcium lactate on in vitro fertilization and embryonic development in cattle.

Objective: Growing demand for embryo transfer is steadily expanding and further studies on in vitro fertilization of cattle. To assess the effect of calcium lactate by replacing Tyrode's Albumin Lactate Pyruvate (TALP) medium composition during fertilization and embryonic development.

Methods: Sodium lactate and CaCl2 were replaced with 2.

Relationships among estrous behavior, superovulatory response and grade 1 embryo sex ratio in superovulated Holstein heifers.

In this study, we first attempted to determine whether the timing of artificial insemination affects the sex ratio of seven-day-old embryos in superovulated Holstein heifers. The superovulatory treatment consisted of eight decreasing doses of FSH for 4 days and 2 doses of PGF(2alpha) given with the last two doses of FSH. The superovulated heifers were given a GnRH analogue 48 h after the first PGF(2alpha) treatment and were artificially inseminated 48 h (n=10) or 56 h (n=8) after the first PGF(2alpha) treatment.

Improved cryopreservation of bovine preimplantation embryos cultured in chemically defined medium.

The aim of this study was to examine the effects of modifications to a standard slow freezing protocol on the viability of in vitro produced bovine embryos. Bovine oocytes were matured, fertilized with frozen-thawed semen, and presumptive zygotes cultured in defined two-step culture media. The standard freezing medium was 1.

Improved in vitro bovine embryo development and increased efficiency in producing viable calves using defined media.

In this study, we developed a defined culture medium that supported improved in vitro bovine embryo development and calving rate after embryo transfer (ET). In vitro-matured bovine oocytes from abbatoir-derived ovaries from Korean native, HanWoo cattle were fertilized with frozen-thawed spermatozoa and embryos were cultured in two-step culture media. In Experiment 1, embryos were cultured in media supplemented with 8 mg/mL BSA, or 0.

Effects of protein source and energy substrates on the in vitro development of bovine embryos in a two-step culture system.

In this study, we examined the effects of a two-step culture system, which involves the use of different culture media for early cleavage and later stage embryos, on the in vitro development of bovine embryos. We also investigated the effect of glucose, phosphate and citrate on the in vitro early developmental period of bovine embryos in a two-step culture system. Moreover, the supplementation of different protein sources (BSA-V, BSA-FAF and FBS) during IVC did not affect the frequency of blastocyst development.