A Novel Method for Equine Embryo Transfer from Contaminated Recipient Mares into Second Healthy Recipients for Surviving Embryos.

Embryo transfer (ET) is regarded as one of the reproductive methods for genetic improvement initiatives in the horse business. The current study aimed to increase the success rate of ET by re-flushing and re-transferring of embryos from contaminated recipient mares into second healthy recipients. The study involved 25 recipient mares that demonstrated embryonic vesicles inside intraluminal fluid (ILF) on ultrasound scanning 2±0.5 days after ET. Seven recipient mares were left without re-flushing and re-transferring of embryos (control group) and 18 recipient mares (treated group) were subjected to re-flushing and re-transferring of the embryos to second healthy and prepared recipients. The retrieved fluid from treated mares was subjected to microbiological and cytological examinations. The results revealed mixed and single infections, as well as polymorphonuclear neutrophils (PMNs). The total bacterial count and cytology findings revealed that all first recipient mares had endometritis. All control mares showed embryonic death at 14±1.1 days (13-15 days) of embryonic age. In treated group, microscopic evaluation of retrieved embryos revealed a well-developed thick capsule in 12/18 (66.7%) of them and a normal capsule in 6/18 (33.3%). The pregnancy rate in well-developed capsule embryos was greater (66.7%) than in typical capsule embryos (33.3%). This study illustrates the value of swabbing the uterus of the recipient mares during estrus prior to ET and their checking at 2 days after ET. In addition to boosting pregnancy rates in ET commercial programs, our novel method can protect the embryos from the harmful effects of the inflammatory process and help them survive.

A case of a twin surviving to term following the abortion of its co-twin at 9 months in an Arabian mare.

Twin pregnancy in mares is one of the leading causes of abortions. Abortion invariably impacts both fetuses. This report describes an unusual case of a twin surviving to term following the abortion of its co-twin at 9 months in a 7-year-old Egyptian Arabian mare. At the time of abortion at 9 months of gestation, the size of the aborted fetus was equivalent to one of approximately 5 months of age while the age of the live co-twin was 9 months. Both fetuses were males. A skin sample was collected from the aborted fetus and hair samples were collected from the dam, sire and live foal for parentage analysis. The parentage analysis confirmed that both fetuses were by the same dam and sire stallion. The authors suggest several scenarios to explain this condition. This report describes a unique case of a twin surviving to term following the abortion of its co-twin at 9 months in a mare.

Embryo transfer into anestrous recipient mares prepared using clomiphene citrate and short-acting progesterone.

Embryo transfer (ET) is an important technology for genetic improvement programs in the equine industry. Many protocols have been used for preparation of recipients. This study evaluates a new protocol for preparation of acyclic embryo recipient mares using clomiphene citrate (CC) and short-acting oral progesterone (Altrenogest). Seventy-two native breed recipient mares were divided into 2 groups. Group 1(G1) included 60 non-cyclic mares with follicular structures ≤ 15 mm in diameter that received CC and Altrenogest. Group 2 (G2) included 12 cyclic recipient mares that served as a control group. G1 mares were treated with oral CC at a dose of 250 mg for 4 days followed by oral administration of Altrenogest for 6 days. Ultrasonography was carried out for evaluation of uterine echotexture response to hormonal treatment, and pregnancy diagnosis post ET. Serum estradiol and progesterone concentrations were also assessed. All data were statistically analyzed. The results revealed that the serum progesterone concentrations in G1 were higher than G2 (P < 0.001). There was no difference in the estradiol concentrations between both groups during diestrus phase (P > 0.05). The pregnancy rate was higher in G1 (83.3 %) than G 2 (66.6 %). In conclusion, using oral CC and Altrenogest, as a new protocol, was effective for preparation of acyclic recipient mares in this study.