Data of three first seasons of embryo transfer from two clones of the same mareJournal of Equine Veterinary Science

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Authors
H. Terris, L. Normandin, H. Quinton, J.F. Bruyas
Year
2012
DOI
10.1016/j.jevs.2012.05.041
Subject
Equine

Text

ultrasound examination per rectum and 35-day pregnancy rates were recorded. The Chi-square test was used to compare values. The results in Table I show that the 35-day pregnancy rate of recipient mares that had embryos transferred following their first postpartum ovulation was 65% (151 pregnancies/ 232 embryos transferred). There was no difference in pregnancy rates between recipient mares that ovulated 8-12 days versus 13-17 days after ovulation. The results in Table II show that the 35-day pregnancy rate of recipient mares was 83% (15 pregnancies/18 transferred foal heat embryos).

In conclusion, mares on their foal heat can serve as embryo recipients. Furthermore, when embryos are recovered from donor mares inseminated on the first postpartum estrus, recipient pregnancy rates are high. conclusion, a mare cloned can present a fertility to be

Table 1

The Pregnancy Rate of Recipient Mares Following Embryo Transfer after the First PP Cycle

Ovulation day after foaling Transfers Pregnancies Pregnancy Rate 8 18 8 44% 9 32 20 63% 10 51 37 73% 11 51 30 59% ne VetAcknowledgements

The authors would like to thank the following veterinarians for generously providing data for this retrospective study:

Rob Foss, Lea Arnold, David Hartman, Glenn Blodgett, Brian

Carroll, Dee Gragg, and Chelsie Burden.

References 12 26 18 69% 13 28 10 56% 14 14 9 64% 15 12 11 92% 16 7 5 71% 17 3 2 66%

TOTAL 232 151 65%

Table 2

The Pregnancy Rate of Recipient Mares Following the Transfer of Embryos

Produced on Foal Heat Ovulation versus Subsequent Cycles

Embryo Type Embryos (n) Pregnant 35 days (n) Pregnancy rate

Foal Heat 18 15 83%

Non-Foal Heat 1314 1027 78%underwent serial pregnancy ultrasound exams per rectum following transfer and 35-day pregnancy rates were recorded. Pregnancy rates were compared between recipient mares that ovulated 8-12 versus 1317 days postpartum. Study 2: Blastocysts (n ¼ 18) recovered from mares following insemination on their first PP ovulation were transferred transcervically into recipient mares that were either nonfoal-heat mares or nonlactating mares. The recipient mares underwent 8th ISEET Abstracts / Journal of Equi414[1] Blanchard TL, Thompson JA, Love CC, et al. Influence of day of postpartum breeding on pregnancy rate, pregnancy loss rate, and foaling rate in Thoroughbred Mares. 2012: Theriogenology in press.used as an embryo donor, and then optimize the diffusion of its genotype (here with 2 clones mean 3.3 foals/year).

Additionally, two mares cloned from the same mare, of the same age, breed in the same conditions, with the same stallions don't present the same breeding performances. This difference could be linked to the influ-[2] Koskinen E, Katila T. Uterine involution, ovarian activity and fertility in the post-partum mare. J Reprod Fertil 1987;Suppl 35: 733-4. [3] Huhtenin M, Reilas T, Katila T. Recovery rate and quality of embryos from mares inseminated at the first post-partum oestrus. Acta Vet

Scand 1996;37(3):343-50.

Data of three first seasons of embryo transfer from two clones of the same mare

H. Terris 1, L. Normandin 1, H. Quinton 3, and J.f. Bruyas 2 1Haras de Hus, 44 390 Petit Mars, France, 2 Lunam

Université, Oniris, Ecole Nationale Vétérinaire,

Agroalimentaire et de l'alimentation Nantes-Atlantique, 44 300 Nantes, France, 3 Embryotop-Urceo, 35 702

Rennes, France

Since the birth of Prometea, the first cloned horse, very few mares have been cloned until now. Two cloned mares produced by K. Hirincks' team from same sample of skin fibroblasts collected by E. Palmer (Cryozootech), are born respectively the 30 and the 31 of March 2007, in an insemination and embryo transfer center where they lived until now. From their 2 years old, they were breed as embryo donors, in exactly the same conditions, using for the both clones same stallions (3 or 4 per breeding season). Those stallions were chosen as potential fathers, and were used successively during each season for the two clones. The aim of this work was to test the embryo donor potential of cloned mares, and to compare the results obtained by two clones of the same mare. For each followed cycle, during 2009, 2010 and 2011 breeding seasons, mares were inseminated classically with fresh, cooled or frozen-thawed semen of one of the nine selected stallions and embryo recoveries and transfers were performed in accordance with the classical nonsurgical techniques. Pregnancy diagnoses were done by ultrasound on day 7 after embryo transfer D14 and regularly after. Results are summarized in Tables 1 and 2.

For both 2 clones, 14 embryos were collected by 32 uterine flushes attempts (44%), 13 (93%) pregnancies were obtained at D14, and 4 foals were born (2 in 2010, 2 in 2011) and 6 others are expected in March 2012. On 13 early pregnancies, a late embryonic death (D14< <D45), an early abortion (D45 < <D180) and a late abortion (>

D180) were observed; two of those 3 pregnancies have been initiated with the same stallion. However, one clone mare seems to be less efficient donor mare than the other (P < 0.05), with only 2 expected foals for 5 embryos collected and transferred and 18 embryo collections versus 4 born and 4 expected foals for 9 embryos collected and transferred and 14 embryo collections. In erinary Science 32 (2012) 397-422ence of recipient oocytes and/or to other epigenetical phenomenons. mem ld) 0 B 0/ ne VetTable 1

Data on embryo collections and transfers performed on 2 clones from the sa years, in regards to different stallions

Stallions 2009 (2 years old) 2010 (3 years o

Clone 1 Clone 2 Clone 1

E/R D14 D180 B E/R D14 D180 B E/R D14 D18

De 0/2 - - - 1/2 1/1 1/1 F

F H 1/2 0/1 - - 1/1 1/1 0/1 F 0/1 - - - 1/2 1/1 1/1 F

L 1/2 1/1 1/1

T 0/3 - Dr Q 0/4 - D J 8th ISEET Abstracts / Journal of EquiAdministration of deslorelin or hCG at the time of embryo transfer: effect on pregnancy rates in recipient mares

P.M. McCue 1, L.K. Arnold 2, B.S. Carroll 3, C.A. Burden 3,

D.M. Gragg 3, D.B. Scofield 1, J.N. Hatzel 1, and R.A. Ferris 1 1 Fort Collins, Colorado, 2Weatherford, TX, 3Oklahoma