Survival of day-4 embryos from young, normal mares and aged, subfertile mares after transfer to normal recipient mares.

The estimated embryonic loss rate between Days 4 and 14 after ovulation for young, normal mares (9%) was significantly lower (P less than 0.01) than the estimated embryonic loss rate for aged subfertile mares (62%). Fertilization rates, which were based on the recovery of embryos at Day 4 after ovulation, were 96% and 81% (P less than 0.1) for normal and subfertile mares, respectively. Day-4 embryos were collected from the oviducts of normal and subfertile donors mares. These embryos were transferred to the uteri of synchronized, normal recipient mares to test the hypothesis that the high incidence of embryonic loss in subfertile mares was related to embryonic defects. The hypothesis was supported because embryo survival rates were significantly higher (P less than 0.05) for Day-4 embryos from normal compared to subfertile mares. These defects may have been intrinsic to the embryo or might have arisen due to the influence of the oviducal environment before Day 4 after ovulation.

[1]  N. C. Savage.  Ultrasonic Imaging and Reproductive Events in the Mare , 1988 .

[2]  J. Lowe,et al.  Autotransfer of Day 4 embryos from oviduct to oviduct versus oviduct to uterus in the mare. , 1987, Theriogenology.

[3]  B. Ball,et al.  Survival of equine embryos transferred to normal and subfertile mares. , 1987, Theriogenology.

[4]  B. Ball,et al.  Survival of day 4 embryos transferred from the oviduct of normal and subfertile donor mares to the uterus of normal recipient mares , 1987 .

[5]  R. Foote,et al.  Effect of donor-embryo-recipient interactions on pregnancy rate in a large-scale bovine embryo transfer program , 1987 .

[6]  J. Roche,et al.  Reproductive wastage in the mare and its relationship to progesterone in early pregnancy. , 1987, Journal of reproduction and fertility. Supplement.

[7]  H. Erb,et al.  Early pregnancy loss in brood mares. , 1987, Journal of reproduction and fertility. Supplement.

[8]  B. Ball,et al.  Pregnancy rates at Days 2 and 14 and estimated embryonic loss rates prior to day 14 in normal and subfertile mares. , 1986, Theriogenology.

[9]  D. Schlafer,et al.  Recovery and evaluation of embryos from normal and infertile mares. , 1986, The Cornell veterinarian.

[10]  E. Squires,et al.  Effect of exogenous progesterone on pregnancy rates after surgical embryo transfer in mares. , 1986, Theriogenology.

[11]  M. Diskin,et al.  The Extent and Timing of Embryonic Mortality in the Cow , 1986 .

[12]  S. Echternkamp,et al.  Repeat-Breeder Females in Beef Cattle: Influences and Causes1,2 , 1985 .

[13]  E. Squires,et al.  Some observations on early embryonic death in mares , 1985 .

[14]  L. Donaldson.  Effect of age of donor cows on embryo production , 1984 .

[15]  R. Pierson,et al.  Ultrasonic anatomy and pathology of the equine uterus. , 1984, Theriogenology.

[16]  R. W. Wright,et al.  Bovine embryo morphology and evaluation. , 1983, Theriogenology.

[17]  R. Foote,et al.  Superovulatory responses of Holstein cows , 1983 .

[18]  K. Betteridge,et al.  Development of horse embryos up to twenty two days after ovulation: observations on fresh specimens. , 1982, Journal of anatomy.

[19]  Douglas Rh.  Some aspects of equine embryo transfer. , 1982 .

[20]  E. Squires,et al.  Factors affecting reproductive efficiency in an equine embryo transfer programme. , 1982, Journal of reproduction and fertility. Supplement.

[21]  R. H. Douglas.  Some aspects of equine embryo transfer. , 1982, Journal of reproduction and fertility. Supplement.

[22]  B. Shea.  Evaluating the bovine embryo. , 1981, Theriogenology.

[23]  W. King,et al.  Morphological study of the bovine blastocyst with phase contrast microscopy. , 1980, Theriogenology.

[24]  G. Seidel,et al.  Embryo transfer in fertile and infertile cows , 1979 .

[25]  N. Ayalon.  A review of embryonic mortality in cattle. , 1978, Journal of reproduction and fertility.

[26]  Kenney Rm.  Cyclic and pathologic changes of the mare endometrium as detected by biopsy, with a note on early embryonic death. , 1978 .

[27]  R. Kenney.  Cyclic and pathologic changes of the mare endometrium as detected by biopsy, with a note on early embryonic death. , 1978, Journal of the American Veterinary Medical Association.

[28]  T. A. Ryan,et al.  Minitab Student Handbook , 1979 .

[29]  G. Seidel,et al.  Effect of heterospermic insemination on fertility of cattle. , 1975, Journal of animal science.

[30]  C. E. Adams.  Effects of Maternal Age on Ovulation, Fertilization and Embryonic Development , 1975 .

[31]  G. Blaha.  Egg Transfer between Old and Young Mammals , 1975 .

[32]  L. Rowson,et al.  Surgical and non-surgical egg transfer in horses. , 1975, Journal of reproduction and fertility. Supplement.

[33]  R. Foote,et al.  Maternal ageing and embryonic mortality in the rabbit. I. Repeated superovulation, embryo culture and transfer. , 1971, Journal of reproduction and fertility.

[34]  O. Knudsen.  ENDOMETRIAL CYTOLOGY AS A DIAGNOSTIC AID IN MARES. , 1964, The Cornell veterinarian.