Gamete intrafallopian transfer

Perspectives on the development and incorporation of assisted reproduction in the equine industry

Marked changes in equine breeding technologies have occurred over the past 25 years. Although there have been numerous reviews on assisted reproduction techniques for horses, few publications include the acceptance and impact of these techniques on the horse industry. In this review, several techniques are discussed, with an emphasis on how they developed in the horse industry and altered equine reproductive medicine. Embryo transfer has become a widely used technology, allowing multiple foals to be produced per year. Embryos can be collected, cooled or frozen, and shipped to a distant facility for transfer into recipient mares. Failure to obtain embryos from some mares stimulated the development of oocyte collection and transfer. Oocyte technologies became more practical when intracytoplasmic sperm injection was developed in the early 2000s. There are now facilities across the world that routinely produce embryos invitro. Cryopreservation of oocytes has lagged because of limited success, but embryo cryopreservation is commonplace. Techniques such as sex-sorted semen, superovulation and genetic diagnosis of embryos are not widely used, and they will require more development before they are established in the horse industry in a cost-efficient manner.

The periconceptional environment and cardiovascular disease: does in vitro embryo culture and transfer influence cardiovascular development and health?

Assisted Reproductive Technologies (ARTs) have revolutionised reproductive medicine; however, reports assessing the effects of ARTs have raised concerns about the immediate and long-term health outcomes of the children conceived through ARTs. ARTs include manipulations during the periconceptional period, which coincides with an environmentally sensitive period of gamete/embryo development and as such may alter cardiovascular development and health of the offspring in postnatal life. In order to identify the association between ARTs and cardiovascular health outcomes, it is important to understand the events that occur during the periconceptional period and how they are affected by procedures involved in ARTs. This review will highlight the emerging evidence implicating adverse cardiovascular outcomes before and after birth in offspring conceived through ARTs in both human and animal studies. In addition, it will identify the potential underlying causes and molecular mechanisms responsible for the congenital and adult cardiovascular dysfunctions in offspring whom were conceived through ARTs.

One year old fillies can be successfully used as embryo donors

One year old fillies are able to conceive but, usually, not to give birth to a living foal. Although embryo transfer allows the production of foals from mature mares with repeated pregnancy losses, no reports are available on the use of one year old fillies as embryo donors. To evaluate this possibility, eleven 12-16 months old Haflinger mares were inseminated with fresh semen and subjected to embryo recovery. Some of the recovered embryos were non-surgically transferred into synchronized mature recipients. Pregnancies were terminated using PGF2alpha at day 25. Fillies' embryo recovery rate and their recipients' pregnancy rate at day 25 were compared with those achieved in two years old and mature mares of the same breed, subjected to the same management. Embryo recovery rate was 21/44 (47.7%), 12/16 (75%) and 22/26 (84.6%) (P>0.01) for one year old, two years old and mature mares, respectively. Five/7 (71.4%) one year old donors' embryos resulted in a pregnancy after transfer and 4/7 (57.1%) developed until day 25. Significant differences in pregnancy rates after transfer between donors' age groups were not observed; no short term side effects resulted from the use of fillies as embryo donors. This study showed that one year old mares employed as embryo donors produce embryos both morphologically normal and able to develop in recipient mares at least up to day 25 of pregnancy.

New commercial opportunities for advanced reproductive technologies in horses, wildlife, and companion animals

As advanced reproductive technologies become more efficient and repeatable in livestock and laboratory species, new opportunities will evolve to apply these techniques to alternative and non-traditional species. This will result in new markets requiring unique business models that address issues of animal welfare and consumer acceptance on a much different level than the livestock sector. Advanced reproductive technologies and genetic engineering will be applied to each species in innovative ways to provide breeders more alternatives for the preservation and propagation of elite animals in each sector. The commercialization of advanced reproductive techniques in these niche markets should be considered a useful tool for conservation of genetic material from endangered or unique animals as well as production of biomedical models of human disease.

Fertility of mares after unilateral laparoscopic tubal ligation

OBJECTIVE

To develop a technique for laparoscopic tubal (oviductal) ligation and to evaluate pregnancy rates for mares that ovulated ipsilateral or contralateral to the ligated oviduct.

STUDY DESIGN

Randomized prospective clinical trial comparing pregnancy rates after unilateral laparoscopic tubal ligation.

ANIMALS

Twelve mares of light horse breeds.

METHODS

One oviduct in each of 6 mares was surgically ligated with a laparoscopic technique; 6 other mares served as nonligated controls. Mares with unilateral tubal ligations (UTL) were inseminated with 500 million progressively motile sperm during 1 cycle when the dominant follicle was ipsilateral to the ligation site and 1 cycle when the dominant follicle was contralateral to the ligation site. Control mares were bred during 2 cycles regardless of the side of the dominant follicle. Pregnancy examinations were performed on days 12, 14, and 16 after ovulation by transrectal ultrasonography.

RESULTS

None of the mares became pregnant when ovulations occurred from the ovary adjacent to the ligated oviduct. All 6 mares became pregnant on the first cycle when an ovulation occurred from the opposite ovary. Control mares became pregnant on 10 of 12 cycles (83.3 %).

CONCLUSIONS

UTL was completely effective in preventing pregnancy when ovulation occurred ipsilateral to the ligation site. The surgical procedure did not interfere with the establishment of pregnancy when ovulation occurred from the contralateral ovary.

CLINICAL RELEVANCE

UTL may be a clinically useful procedure for preparing a recipient mare for gamete intrafallopian transfer. The recipient mare could be allowed to ovulate and UTL would prevent fertilization of her oocyte but would not interfere with normal corpus luteum formation. The donor oocyte could be placed into the oviduct contralateral to the UTL site.