Embryo transfer in cattle experience of twenty-four completed cases

Betteridge, K.J.; Mitchell, David

doi:10.1016/0093-691x(74)90009-0

Cited by 23 publications

(7 citation statements)

References 19 publications

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“…Collections were made surgically on Days 2, 3 and 4 (6, 4 and I animals, respectively), after slaughter in one case on Day 4, or by a routine non-surgical transcervical procedure on Days 5,6,7 and 14 (7, 7, 8 and 2 heifers, respectively). The surgical recoveries were made through a mid-ventral abdominal incision under general anaesthesia (Betteridge & Mitchell, 1974). Before surgery, animals were deprived of food for 36-48 h and of water for 24 h. Anaesthesia was induced by intravenous injection of thiamylal sodium (10 mg/kg body weight) and maintained by halothane in oxygen in a closed-circuit system.…”

Section: Methodsmentioning

confidence: 99%

Nucleolus organizer regions and nucleoli in preattachment bovine embryos

King¹,

Niar²,

Chartrain³

et al. 1988

Reproduction

127

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Embryos (1-cell to elongated blastocyst stage) were recovered from superovulated heifers at surgery (Days 2-4; oestrus = Day 0), after slaughter (Day 4), or by transcervical flushing (Days 6, 7 and 14). The 175 embryos were cultured for 4, 8, 24 or 48 h, fixed on slides and sequentially stained with Giemsa and silver nitrate. Twenty-three 2-cell to blastocyst-stage embryos were fixed, embedded and examined by transmission electron microscopy. Argentophilic nucleolus organizer regions (Ag-NORs), indicative of transcriptionally active rRNA genes, were observed in embryos in which short- or long-term culture began at or after the late 8-cell stage. The nucleoli of embryonic cells also showed increased affinity for silver from the 8-cell stage onward. Differences in the number of Ag-NORs observed after the 8-cell stage reached statistical significance only when Day-5 and Day-7 embryos cultured for 4 h were compared. Ultrastructurally, the nucleoli were seen to develop from small, dense, fibrillar masses at the 2-cell stage, to ring-shaped structures (signifying a low level of activity) at the 8-cell stage. At the 16-cell stage the nucleoli became reticulated, suggesting an increase in activity, and by the morula and blastocyst stages they were characteristic of fully active nucleoli. It is concluded that a significant transcriptional activity of the rRNA genes in the embryos of cattle begins around the 8-cell stage.

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Section: Methodsmentioning

confidence: 99%

Nucleolus organizer regions and nucleoli in preattachment bovine embryos

King¹,

Niar²,

Chartrain³

et al. 1988

Reproduction

127

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“…They had access to the outside except for Ayerst Laboratories, Montreal) between Days 6 and 14 of the oestrous cycle, followed 40-44 h later by a single i.m. injection of a prostaglandin (25 or 30 mg PGF-2a: Upjohn; 100 mg analogue AY 24655: Ayerst; or 500 µg cloprostenol (Estrumate): Imperial Chemical Industries Ltd), and 12 donors received PMSG only (Betteridge & Mitchell, 1974). Donors were inseminated naturally or artificially (with fresh or frozen semen) on the first day of the ensuing oestrus and again the following day when AI was used, or if the animals would stand for the bull.…”

Section: Introductionmentioning

confidence: 99%

“…Embryos were collected aseptically from responding donors at surgery (94 donors) or slaughter (97 donors) on Days 10-16. The techniques for anaesthesia, surgical exposure of the reproductive tract, pre-and post-operative care, and collection of tracts from slaughtered animals were as described previously (Betteridge & Mitchell, 1974). For flushing, a Foley catheter (18 French gauge) was inserted through a puncture made with closed artery forceps near the base of each uterine horn.…”

Section: Introductionmentioning

confidence: 99%

“…There were 84 single transfers to the uterine horn ipsilateral to the corpus luteum and 51 twin transfers, one embryo being placed into each horn. Embryos were transferred as described previously (Betteridge & Mitchell, 1974) using Pasteur pipettes up to 1-5 mm in diameter depending on embryo size. Transfers were made in TCM-199 except for 8 single and 13 twin transfers for which PB1 was used.…”

Section: Introductionmentioning

confidence: 99%

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Collection, description and transfer of embryos from cattle 10-16 days after oestrus

Betteridge¹,

Eaglesome²,

Randall³

et al. 1980

Reproduction

Self Cite

237

117

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Of 226 donor cattle treated with PMSG to induce superovulation, 76.5% responded with 3 or more ovulations. Flushing at surgery or slaughter 10-16 days after oestrus recovered eggs and embryos that represented 49.3% of the number of ovulations. Of those recovered, 73.3% were embryos, an average yield of 4.0 embryos/treated cow or 4.8 embryo/flushed cow. The location of eggs and embryos was determined in 65 of the donors. Embryos and unfertilized eggs (6.1% of those recovered) were occasionally found in the oviducts. Empty zonae pellucidae were also found in the uterus on all days. The lengths, or diameters, of embryos were extremely variable within days and within donors, but mean values indicated logarithmic growth between Days 10 and 16. Eighty-four synchronous (+/- 1 day) recipients received single embryos, and 51 recipients twin embryos, by surgical transfer. Pregnancies were obtained in recipients up to Day 16 but not on Day 17, indicating the stage by which an embryo must be present to prevent luteolysis. The overall pregnancy rate at Day 42 was 50.4% and further 18.1% of the recipients exhibited extended oestrous cycles. Of 35 recipients that were allowed to go to term, 12 lost their pregnancies, most often between Days 42 and 63.

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“…It was later reported, however, that bovine follicular fluid would support limited cleavage of cattle eggs (Thibault, 1966;Sreenan, 1968) and shortly afterwards successfully employed Tissue Culture Medium (TCM) 199 as a recovery and transfer medium. Although TCM 199 was used in the early and mid-1970s by the Cambridge group, as well as by Betteridge and Mitchell (1974), Sreenan and Beehan (1974), Sreenan et a/. (1975) and many others, it was by no means regarded as an ideal medium.…”

Section: Media Employed In Recovery and Transfermentioning

confidence: 99%