Application of embryo biopsy and sex determination via polymerase chain reaction in a commercial equine embryo transfer program in Argentina

2019 ◽  
Vol 31 (12) ◽  
pp. 1917 ◽  
Author(s):  
F. L. Riera ◽  
J. E. Roldán ◽  
J. M. Espinosa ◽  
J. E. Fernandez ◽  
I. Ortiz ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Pregnancy Rate ◽  
Embryo Transfer ◽  
Embryo Biopsy ◽  
Transfer Program ◽  
Chain Reaction ◽  
Embryo Transfer Program ◽  
Polymerase Chain ◽  
Accuracy Of Prediction ◽  
In Pregnancy

Embryo biopsy for fetal sexing has clinical application, but few reports are available of its use within an active embryo transfer program. We evaluated results on biopsy of 459 embryos over one breeding season. There were no significant differences in pregnancy rate between biopsied and non-biopsied embryos (72% vs 73%) or for biopsied embryos recovered at the centre (73%) compared with those shipped overnight (72%). However, the pregnancy rate decreased significantly in shipped embryos biopsied ≥20h after collection. Overall, 86% of biopsies provided a sex diagnosis. The likelihood of a positive genomic (g) DNA result was significantly higher for biopsies from large blastocysts (96%) than from smaller embryos (70–85%). In total, 38% of biopsies were positive for Y chromosome DNA (Y-DNA) and were diagnosed as male. Subsequently, 95% of Y-DNA-positive embryos were confirmed as male and 78% of Y-DNA-negative embryos were confirmed as female. The accuracy of prediction of female (Y-DNA negative) was significantly higher when the biopsy sample was probed for Y-DNA only compared with probing for both gDNA and Y-DNA. We estimate that by transferring only Y-DNA-negative embryos, 3% of potential female pregnancies may have been lost, and production of male pregnancies was reduced by 72%.

172 PREGNANCY RATES AND EARLY PREGNANCY LOSSES IN POSTPARTUM EQUINE EMBRYO RECIPIENTS

2010 ◽  
Vol 22 (1) ◽  
pp. 244
Author(s):  
M. E. Demarchi ◽  
A. M. Tirone ◽  
J. Aguilar ◽  
L. Losinno
Keyword(s):  
Embryo Transfer ◽  
Early Pregnancy ◽  
Pregnancy Loss ◽  
Early Pregnancy Loss ◽  
Transfer Program ◽  
Transfer Programs ◽  
Embryo Transfer Program ◽  
Breeding Seasons ◽  
In Pregnancy ◽  
Loss Rates

In commercial equine embryo transfer programs, the cost of recipient mares represents one of the major economical items that increases the final cost of the pregnancies (Douglas 1985; Losinno and Alvarenga 2006). Due to the risks to newborn foal, it is uncommon to use foaling recipients in the large equine embryo transfer programs in Argentina. The objective of this study was to evaluate pregnancy and early embryonic loss rates between foaling and non-foaling recipients in a commercial embryo transfer program. A total of 173 embryos were collected from Arabian donor mares during 3 consecutive breeding seasons, 2006-2009. Donor mare’s ages ranged from 2 to 22 years, and donors were inseminated with either fresh or frozen semen from 8 stallions 2-17 years old and of proved fertility. Uterine flushing was performed on Day 8 to 9 post-ovulation by standard techniques (Douglas 1985) and recovered embryos were transferred nonsurgically. Recipient mares 3-12 years old were selected clinically by rectal palpation and ultrasound. All embryos were transferred to synchronized recipient mares (-1 to +1 according to donor’s ovulation day) and randomly assigned to non-foaling (n = 84) or foaling (n = 89) recipient groups. For the analysis, we first considered pregnancy and early pregnancy loss rates in both groups, and second, the foaling mares were divided in 3 groups according to the days between foaling and transfer: 1) before 30 days postpartum (n = 10), 2) between 31 and 60 days postpartum (n = 30), and 3) after 61 days postpartum (n = 49). Pregnancy diagnosis was performed by ultrasonography on Days 14, 30, and 60 post-ovulation of the donor. Results were evaluated by chi-square test. No statistical differences (P > 0.05) were observed in pregnancy rates between non-foaling and foaling recipients (76.2% and 80.9%, respectively) and in post-foaling groups (80% for recipients transferred before 30 days postpartum, 73.3% for recipients transferred between 31 to 60 days postpartum, and 85.7% for recipients transferred after 61 days postpartum). No statistical differences (P > 0.05) were found in pregnancy loss rates between recipients transferred before 30 and after 61 days postpartum (25% v. 4.8%, respectively) and between recipients transferred before 30 days postpartum and the non-foaling group (25% v. 10.9%, respectively). Pregnancy loss rates for recipients transferred after 31 and 61 days postpartum (9.1% and 4.8%, respectively) were not significantly different with the non-foaling group, and both are within previously reported values. Our results show that postpartum recipients can be used 30 days after normal foaling in a commercial embryo transfer program with similar pregnancy and early pregnancy loss rates and can be a valuable tool maximizing the use of the recipient mares during consecutive breeding seasons.

189 PREGNANCY RATES IN HEAT-STRESSED DAIRY CATTLE RECEIVING ONE OR TWO IN VITRO-PRODUCED EMBRYOS IN A TIMED EMBRYO TRANSFER PROGRAM

2006 ◽  
Vol 18 (2) ◽  
pp. 202
Author(s):  
M. Franco ◽  
J. Block ◽  
F. D. Jousan ◽  
L. A. de Castro e Paula ◽  
A. M. Brad ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Pregnancy Rate ◽  
Embryo Transfer ◽  
Fetal Loss ◽  
Pregnancy Rates ◽  
Uterine Horn ◽  
Limiting Factor ◽  
Transfer Program ◽  
In Pregnancy

The objective was to determine whether transfer of two embryos would increase pregnancy rates in heat-stressed dairy recipients receiving an in vitro-produced embryo transferred into the uterine horn ipsilateral to the corpus luteum (CL). Such a treatment would increase the likelihood that the cow receives at least one embryo competent for sustained development. In addition, transfer of two embryos into the ipsilateral uterine horn is likely to increase the amounts of interferon-tau and other embryonic-signaling molecules in the uterus. A total of 32 virgin crossbreed heifers and 26 lactating crossbreed cows were used as timed embryo transfer recipients after being subjected to an ovulation synchronization protocol as follows: GnRH (100 �g) and insertion of previously used progesterone-containing CIDR on Day -10, prostaglandin F2� and CIDR removal on Day -3, and GnRH (100 �g) on Day 0 (day of anticipated ovulation). All recipients had a palpable CL on Day 6 and were randomly selected to receive one (n = 31 recipients) or two (n = 27) embryos on Day 7. At Day 64, the pregnancy rate tended to be higher (P = 0.07) for cows than for heifers. While not significant, heifers that received two embryos tended to have lower pregnancy rates than those that received a single embryo (20% vs. 41%); there was no difference in pregnancy rate in cows (50% for two embryos vs. 57% for one embryo). Pregnancy losses between Day 64 and Day 127 occurred in one group only cows receiving two embryos. In that group, pregnancy rate was 50% at Day 64 but 17% at Day 127. Overall, there was no difference in pregnancy rates at day 127 between cows and heifers, but recipients that received two embryos (17% for cows and 20% for heifers) had lower pregnancy rates (P < 0.03) than recipients that received one embryo (57% for cows and 41% for heifers). Only one animal, a cow, had twin fetuses at day 127. In conclusion, unilateral transfer of two embryos failed to improve pregnancy rates of dairy cattle exposed to heat stress. The fact that fetal loss occurred sooner for heifers than for cows points out the importance of uterine capacity as a limiting factor for maintenance of fetal development of two conceptuses. The suitability of timed embryo transfer was evident from the high pregnancy rates achieved with crossbreed females that received a single embryo. This work was supported by BARD Grant No. US-1551-14, USDA TSTAR Grant No. 2004-14135-14715, Grant No. 2001-12101-11318 from the USDA-IFAFS Program, and CAPES Grant No. 134202-1).

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