摘要:

SummaryEmbryo recovery rates from commercial donor mares mated at the clients' farms and commercial and research donors mated at the authors' laboratory were 27, 59 and 57 per cent, respectively. Transfer of embryos recovered on Days 6 to 8 post ovulation to recipients that were −1, −2 or −3 days asynchronous with the respective donor gave pregnancy rates of 54, 40 and 60 per cent respectively. No pregnancies were produced from the transfer of Days 9 and 10 embryos to recipients that were asynchronous with the d

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1985.tb04603.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryThe production of a live foal via embryo transfer is dependent upon collection of a viable embryo, transfer of the embryo into an appropriate recipient and successful establishment and maintenance of a pregnancy within the recipient. Several factors have been identified that affect embryo recovery. These include age of embryo, reproductive status of the donor and number of detected ovulations. Pregnancy rates have been shown to be influenced by the method of transfer, the technician involved, the time of year, the age and size of embryo and the synchrony of donor and recipient. Data on each of these factors as they affect embryo recovery and transfer are presented and discussed.

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1985.tb04604.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryA total of 264 non‐surgical embryo recovery attempts, performed at Day 6 to 10 after ovulation on 11 Polish pony donor mares (350 to 420 kg body weight), yielded 152 embryos (58 per cent). Recovery rate per mare over a six‐year period averaged 15 embryos with a range of six to 24 embryos.Non‐surgical transfer of 19 Polish pony embryos to heavy‐type recipient mares (620 to 800 kg body weight) resulted in five live foals, all of which were appreciably taller and heavier at birth than equivalent control foals born to Polish pony mares. The transferred foals grew much faster during the period of suckling than the control foals and they have remained bigger to the present time, when the two oldest foals are 2.5 years of age. These preliminary findings indicate that the size of the recipient mare may significantly influence the final size of its offspring achieved by embryo t

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1985.tb04605.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1985.tb04606.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryThe feasibility of collecting equine embryos non‐surgically and returning them non‐surgically to the same donor mare for the continuation of that pregnancy is described. Sixteen reproductively normal, cycling mares were the subject of 65 embryo collection attempts between May and October. The embryo was held outside the mare for three different time spans (0, 2 and 4 h) before replacing it into the uterus of the same animal. Two different methods of non‐surgical embryo collection were compared. From 23 collections that involved flushing only the ipsilateral uterine horn on Day 6 post ovulation, 12 embryos (52 per cent) were recovered. From 31 collections that involved flushing the whole uterus on Day 8, 25 embryos (81 per cent) were recovered. None of the non‐surgical auto‐transfers resulted in a full term pregnancy. In 11 mares in which single horn flushing on Day 6 had not produced an embryo, reflushing the whole uterus on Day 8 also failed to yield any embryos.There was no significant difference in the onset of the next oestrus in mares flushed on Day 6 as compared with Day 8, nor did the overall mean (± sd) oestrous cycle lengths of these flushed mares (21.5 ± 4.75 days) differ from those of normal, unflushed mares. Mares that had an embryo replaced in their uteri, either on Day 6 or Day 8, showed no prolongation of their oest

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1985.tb04607.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1985.tb04608.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryEarly pregnancy loss was studied by sequential ultrasound examinations of 404 pregnancies in commercial brood mares. Overall, the rate of early pregnancy loss was 11.1 per cent. More pregnancies were lost at two to four weeks post ovulation than at four to six or six to eight weeks post ovulation (23 of 45 versus nine of 45 or 10 of 45). The mean (±se) number of days from detection of pregnancy loss until the subsequent ovulation was higher for mares in which pregnancy loss was detected at six to eight weeks post ovulation than at the earlier stages (21.1 ± 3.90 versus 12.0 ± 1.59 or 9.5 ± 1.05, respectively). Thirty‐one of 45 mares that lost pregnancies were subsequently mated; 20 (60 per cent) became pregnant but eight of these pregnancies (40 per cent) were again lost.In a second study a total of 84 embryo collection attempts were made from 14 maiden and 14 subfertile mares. More uterine flushes from maiden mares yielded embryos than from subfertile mares (29 of 42 versus 17 of 42). There were more flushes in which one or more normal embryos were recovered from maiden mares than from subfertile mares (28 of 42 versus eight of 42). There were fewer flushes in which only abnormal embryos were recovered from maiden mares than from sub‐fertile mares (one of 42 versus nine

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1985.tb04609.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryEndometrial pathology and prolonged infertility caused a marked reduction in embryo recovery from barren mares. Young maiden mares produced more embryos later, rather than earlier, in the breeding season. Recipient mares with a normal endometrium had a higher pregnancy rate (P<0.05) than recipient mares in which moderate endometrial pathology was observed. Minimal pregnancy loss occurred between the time of embryo transfer and Day 50 of gestation in recipient mares with normal endometria that had been closely synchronised with their respective donor mares.

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1985.tb04610.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

SummaryThe cost effectiveness of using embryo transfer for producing progeny from subfertile donors is assessed. A total of 146 embryo recovery attempts performed on 34 subfertile donor mares yielded 41 transferable embryos (28 per cent recovery rate) from 27 of these mares. Non‐surgical transfer of these embryos achieved an overall pregnancy rate of 54 per cent. Therefore, the efficiency of producing a pregnancy from sub‐fertile donors was about 15 per cent per mated oestrous cycle. Financial calculations based on cost of materials and the maintenance of recipient mares indicates that a commercial embryo transfer unit would have to charge in excess of US8000 per pregnancy to realise a pro

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1985.tb04611.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1985.tb04582.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY