In vitro fertilization of bovine follicular oocytes recovered by laparoscopy

The impact of using newborn bovine serum as fetal calf serum substitute in the in vitro bovine embryos production system

This study was conducted to assess the effects of addition of 10% newborn bovine serum (NBS) in the maturation and culture media of bovine system on oocytes maturation and developed morula and blastocyst rates. For this purpose, 10% NBS was added to in vitro maturation (IVM) medium alone (Experiment I), in vitro culture (IVC) (Experiment II), and in IVM + IVC (Experiment III). In vitro bovine oocytes maturation and developmental rates of bovine embryos were then compared with control group where the basal maturation or culture media were supplemented with 10% fetal calf serum (FCS). Results revealed that maturation, cleavage, morula, and blastocyst formation rates of in vitro fertilized embryos were not significantly different in NBS and control groups in the 3 experiments. In conclusion, NBS is an efficient macromolecule in bovine system when added either to IVM or to IVC or to both stages. Thus, NBS could provide cheaper and more available treatment to be used as FCS substitute in the IVC system of bovines.

Effect of nano-selenium and nano-zinc particles during in vitro maturation on the developmental competence of bovine oocytes

The objectives of the current study were to evaluate the effects of supplemental nano-selenium (NSe) and nano-zinc oxide (NZn-O) particles during in vitro maturation (IVM) on DNA damage of cumulus cells, glutathione (GSH) concentration in bovine oocytes, subsequent embryo development and re-expansion rate of vitrified warmed blastocysts. The current study was conducted on bovine ovaries obtained from a local abattoir and transported to the laboratory in sterile phosphate buffer saline with antibiotics at 37°C, within 1 h after slaughter. Ovaries were pooled, regardless of stage of the oestrous cycle of the donor. Only cumulus-intact complexes with evenly granulated cytoplasm were selected for IVM. Experimental design included the following: Experiment 1 studied the effect of addition of 1.0 µg/mL NSe or NZn-O to IVM medium on DNA damage of cumulus cells; Experiment 2 evaluated the effects of NSe or NZn-O on intracellular glutathione in oocytes and cumulus cells; in Experiment 3, the development of oocytes matured in IVM medium supplemented with 1.0 µg/mL NSe or NZn-O was investigated; and in Experiment 4, the effects of adding 1.0 µg/mL NSe and NZn-O to in vitro fertilisation media on vitrified oocytes and embryos were investigated. The DNA damage in cumulus cells decreased with supplemental NSe and NZn-O at concentration of 1 µg/mL in the IVM medium (180.2 ± 21.4, 55.8 ± 4.3 and 56.6 ± 3.9 for the control and NSe and NZn-O groups respectively). Total GSH concentrations increased following supplementation with 1 µg/mL NSe and 1 µg/mL NZn-O, compared with the control group. Re-expansion rate of vitrified warmed blastocysts in experimental media containing NSe and NZn-O with ethylene glycol was higher than that of the control. In conclusion, providing NSe and NZn-O during oocyte maturation significantly increased both intracellular GSH concentration and DNA integrity of cumulus cells. Optimal embryo development was partially dependent on the presence of NSe and NZn-O during IVM. NSe and NZn-O during oocyte maturation act as a good cryoprotective agents of vitrified, warmed blastocysts.

Role of the oviduct in early embryo development

This review highlights the role of the oviduct in early embryo development, which has to fulfil many aligned and well-tuned tasks during early embryogenesis. The oviductal lining is subjected to dynamic changes to timely accomplish gamete transport, fertilization and embryo development and to deliver a competent and healthy conceptus to the endometrium which can implant and develop to term. Although knowledge about the role of the oviduct is limited, we know that embryos are very sensitive to the environment in which they develop. The success of in vitro embryo production techniques demonstrates that it is possible to bypass the oviduct during early development and, to a certain extent, replicate the conditions in vitro. However, comparative studies show that embryos developed in vivo are superior to their in vitro produced counterparts, underlining our relatively poor knowledge of the biology of the oviduct. Oviduct activity is orchestrated by various factors, depending on cyclic dynamics, which crucially affect the success of tubal transfer and/or (re-)collection of embryos in embryo transfer studies. This paper reviews data which demonstrate that in vivo culture of embryos in the bovine oviduct is a useful tool for the assessment of embryos developed under various conditions (e.g. superovulation vs single ovulation, lactating dairy cows vs non-lactating cows). It is concluded that more work in the field of early embryo development within the oviduct would contribute to improved ART protocols leading to healthy pregnancies and offspring.

A comparison of three methods of recovery of goat oocytes for in vitro maturation and feritilization

Experiments were conducted to determine an efficient method for recovering a large number of usable oocytes and its effect on subsequent in vitro maturation, fertilization and development. Follicular oocytes were recovered from goat ovaries using 3 different methods: aspiration, puncturing and slicing. The average total number of oocytes recovered per ovary was significantly higher by the aspiration method (2.7+/-0.15) than by puncturing (2.2+/-0.13) or by slicing (2.4+/-0.12). However, significantly more good-quality usable oocytes enclosed with compact cumulus cells were obtained by slicing (0.9+/-0.06) than by aspiration (0.5+/-0.07) or by puncturing (0.5+0.06). Time required for processing each ovary by the slicing method was comparatively less (0.90 min) than that required for puncturing (1.83 min) or for aspiration (1.78 min). Usable oocytes recovered by all three methods were matured, fertilized and developed to the blastocyst stage in vitro. There were no significant differences in the subsequent percentages of oocytes maturing, being fertilized and developing in vitro among the 3 methods of recovering oocytes. In conclusion, the recovery of goat oocytes by the slicing method is simple and efficient compared with the aspiration and puncturing methods.

Laparoscopic surgery in adult cattle

Laparoscopy in cattle is a promising tool for clinical diagnosis and treatment. The lower cost of the materials available in addition to the possibility of an intervention on an animal that is sedated does not entail more costs than an exploratory laparotomy. The application of this tool during abdominal explorations and biopsies allows the avoidance of invasive and often useless surgical interventions and even with the diagnosis and prognosis of certain conditions. Surgical techniques currently are limited to abomasopexies; however, never-ceasing progress and improvements in human surgery are expected to affect the future of bovine surgery. With the advancements in the multimedia technology used by universities, the use of laparoscopy as a pedagogic tool definitely has a promising future. Endoscopic exploration of the thorax is possible using the same material as for laparoscopy. In addition, diagnostic and biopsy applications are useful. The use of the laparoscope in different body cavities and for different applications would make the purchase of the required materials more cost-effective.