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1.
Twenty-four 7 day old bovine embryos were collected from spontaneously ovulating heifers. The embryos were classified into three groups; normal, morphologically deviating or degenerated. Electron microscopy was used to ascertain the ultrastructural correlates to the phase contrast microscope classification. This study sustains the conclusion that only those embryos classified as normal blastocysts are likely to undergo further development. 相似文献
2.
Eight heifers, aged 16–17 months and showing normal oestrous cycles, were immunized against a recombinant porcine inhibin α subunit immunogen, together with another 10 heifers of the same age as controls and treated with placebo immunogen. Primary (1 mg immunogen) and two booster (0.5 mg immunogen each) immunizations were administered at 28‐day intervals. Ten days after the second booster immunization, both groups of heifers underwent a superovulation treatment. Each animal was given an intravaginal progesterone releasing sponge, which was withdrawn 7 days following an i.m. injection of 0.5 mg cloprostenol. Heifers were treated with FSH for 4 days and artificially inseminated after oestrus occurred. The embryos were flushed and evaluated 7 days after insemination. Immunization significantly (p < 0.01) increased blood antibody titres against recombinant porcine inhibin α subunit, from pre‐immunizaion and control values of approximately 0.06 of ELISA 450 nm reading to 0.6 to 0.7 after two or three immunizations. The immunized heifers produced on average 15.8 ± 2.8 embryos, significantly (p < 0.05) higher than the yield of 8.3 ± 1.5 in the controls. The number of transferable embryos were non‐significantly higher in immunized than in control heifers (9.6 ± 3.1 vs 5.8 ± 1.6, p > 0.05). The peak plasma oestradiol concentrations were significantly higher in immunized than in control heifers, both immediately after FSH treatment and 20 days thereafter. Plasma P4 concentrations after superovulation were in the range of 20 ng / ml in the immunized heifers, significantly (p < 0.05) higher than the values approximately 15 ng / ml in control heifers. These results indicated that prior immunization against inhibin α subunit stimulated production of antibodies against inhibin, which enhanced follicular developmental response to superovulation and lead to higher yield of total and transferable embryos. Therefore immunization combined with the conventional superovulatory gonadotrophin treatment, can be a simple and efficient method to produce low cost bovine embryos. 相似文献
3.
Early and late blastocysts (D7) of excellent quality were bisected by the transzonal method. The developing semiembryos without zonal protection were transferred to synchronised recipients--heifers. After bilateral transfer of the identical pair (always one semiembryo into one uterine cornu) 79.7% of the heifers were impregnated. The total gravidity was 58.8%. After ipsilateral transfer (the halves transferred individually) gravidity was confirmed in 48.2% of the cases. The survival efficiency of the halves with respect to the number of bisected embryos was 117.6% in bilateral transfer and it decreased to 93.3% after ipsilateral transfer. Identical pregnancies of twins were recorded in 36.8% of the bilateral transfers and in ipsilateral transfers only 20% of the identical pairs survived. We demonstrated the high recuperative and regenerative ability of the bovine 7 day old blastocyst by means of transzonal bisection. This was dependent on the selection of the appropriate embryo, careful manipulation aseptic technique, biologically compatible cultivation medium and rapid transfer. It is possible to attain satisfactory semiembryo survival levels in transplantation work and by means of this a significant increase of the superovulation effect. 相似文献
4.
A Kuzmany V Havlicek G Brem I Walter U Besenfelder 《Reproduction in domestic animals》2011,46(1):e46-e53
This study was performed to investigate the effects, in terms of nuclear material and actin cytoskeleton quantities (fluorescent pixel counts), of four different bovine blastocyst culturing techniques (in vitro, stepwise in vitro‐to‐in vivo, or purely in vivo). Cumulus oocyte complexes from abattoir‐sourced ovaries were matured in vitro and allocated to four groups: IVP‐group embryos developed up to blastocyst stage in vitro. Gamete intra‐fallopian transfer (GIFT)‐group oocytes were co‐incubated with semen for 4 h before transfer to oviducts of heifers. Following in vitro fertilization, cleaved embryos (day 2 of embryo development, day 2–7 group) were transferred into oviducts on day 2. Multiple ovulation embryo transfer (MOET)‐group embryos were obtained by superovulating and inseminating heifers; the heifers’ genital tracts were flushed at day 7 of blastocyst development. Within each group, ten blastocysts were selected to be differentially dyed (for nuclei and actin cytoskeleton) with fluorescent stains. A novel computer program (ColorAnalyzer) provided differential pixel counts representing organelle quantities. Blastocysts developed only in vivo (MOET group) showed significantly more nuclear material than did blastocysts produced by any other technique. In terms of actin cytoskeleton quantity, blastocysts produced by IVP and by day 2–7 transfer did not differ significantly from each other. Gamete intra‐fallopian transfer‐ and MOET‐group embryos showed significantly larger quantities of actin cytoskeleton when compared with any other group and differed significantly from each other. The results of this study indicate that culturing under in vitro conditions, even with part time in vivo techniques, may adversely affect the quantity of blastocyst nuclear material and actin cytoskeleton. The software employed may be useful for culture environment evaluation/developmental competence assessment. 相似文献
5.
N Seike M Teranishi S Yamada R Takakura Y Nagao H Kanagawa 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1989,51(6):1193-1199
A total of 132 embryos were recovered from 17 superovulated donor cows 7 d after estrus. Seventy-four embryos were selected and assigned to 2 treatment groups. The number of whole embryos that were directly transferred (Group A) and bisected (Group B) were 44 and 30 embryos, respectively. Sixty demi-embryos were produced from 30 morulae to blastocyst-stage embryos that were bisected. One hundred-three embryos, including whole and demi-embryos without zonae pellucidae, were nonsurgically transferred. Only one whole or demi-embryo was transferred to each recipients. The pregnancy rate for whole embryos (A) was 63.6% (28/44), while for demi-embryos (B) it was 74.6% (44/59). There was no significant difference between the pregnancy rates of whole embryos (A) and bisected embryos (B) transferred 7 d after estrus. Forty-three calves including the 14 sets of identical twins were obtained from 30 original embryos (143.3%) using the embryo bisection technique. 相似文献
6.
A. Bielanski 《Veterinary research communications》1989,13(3):251-255
The effect of trypsin on the fertilizing capacity of bull semen was investigated as part of the evaluation of the addition of trypsin to semen as a method for destroying or inactivating infectious agents. Parts of the ejaculates from four bulls were treated with 0.3% trypsin solution. Both the treated and untreated aliquots of semen were frozen, thawed and used for the artificial insemination of superovulated heifers. Two hundred and thirty ova and embryos were collected from 22 heifers on day 7 after oestrus (insemination). One hundred and ten out of 164 (67%) embryos and ova from 15 heifers inseminated with trypsin-treated semen were classified as of transferable quality compared to 46 out of 66 (70%) in the control group of 7 heifers (p>0.05). There was no difference in the proportion of fertilized ova or degenerated embryos resulting from the control or trypsin-treated samples of frozen-thawed semen, which is consistent with results obtained previously using fresh semen. 相似文献
7.
This study was designed to examine the effects of age and developmental stage of in vitro‐produced bovine embryos on the cell number of the embryos and to investigate the correlation between the cell number and diameter in the embryos. The diameter and cell number in blastocysts and expanded blastocysts collected on days 7–9 after in vitro fertilization (IVF) were examined. Although the diameters of the blastocysts collected on days 7 and 8 after IVF were smaller than those of the expanded blastocysts collected on day 9, the cell number in both types of embryos was similar. The cell numbers of the blastocysts and expanded blastocysts decreased with increasing embryo age. There were positive correlations between the cell number and diameter in bovine embryos at each stage collected on each day after IVF. However, the value of the correlation coefficient in the day‐9 expanded blastocyst group tended to be higher than that in the other groups. These results indicate that the cell number of in vitro‐produced embryos is affected by the embryonic stage and age. The diameter of the embryo may be potentially used for the viability testing of the expanded blastocysts collected on day 9 after IVF. 相似文献
8.
The objective of this study was to simplify two-step addition of cryoprotectant for vitrification of bovine embryos by developing a one-step procedure. Survival was calculated as a percentage of non-vitrified controls developed from the same batch of oocytes. In experiment 1, bovine blastocysts were vitrified following one- or two-step addition of cryoprotectant. Exposure of embryos to cryoprotectant in one-step resulted in survival rates not significantly lower (p > 0.1) than those obtained by two-step addition (85% vs 98%, respectively). Based on these results, experiments 2-4 were designed to test one-step addition of cryoprotectant more rigorously. Experiment 2 exposed day 7 blastocysts to 6, 7 or 8 M ethylene glycol for 2.5 or 3.5 min. At 24 h post-vitrification, survival of embryos was similar, irrespective of ethylene glycol concentration or exposure time (6 M 38%, 7 M 51%, 8 M 59%; 2.5 min 54%, 3.5 min 45%). In experiment 3, blastocysts were exposed to 7 M ethylene glycol for shorter times (30 or 60 s); 30 s exposure resulted in decreased survival (8% vs 31%, p < 0.05). Experiment 4 concerned one-step addition of cryoprotectant to day 6 bovine morulae, exposed to 7 M ethylene glycol for 1 or 1.5 min. There was no difference in survival between exposure times of 1 or 1.5 min (28% vs 45%, respectively; p > 0.1). It is unclear why many embryos survive vitrification with one-step addition of cryoprotectant, but others do not. Although, one-step addition of cryoprotectant simplifies the vitrification procedure, survival rates were inadequate for routine cryopreservation of in vitro-produced bovine embryos. 相似文献
9.
V Havlicek A Kuzmany S Cseh G Brem U Besenfelder 《Reproduction in domestic animals》2010,45(5):832-837
The objective of this study was to compare the embryo production and quality carried out entirely in vitro or partly in vitro combined with short‐ vs long‐term in vivo culture using the homologous cattle oviduct. The IVM oocytes were in vitro fertilized and cultured for 7 and 8 days (IVP‐Group), or after IVF and 2–3 days of IVC, 4–8 cell stage embryos were endoscopically transferred into oviducts of synchronized heifers (In Vivo‐Group) or IVM oocytes were co‐incubated with spermatozoa for 3–4 h and transferred into the oviducts of synchronized heifers (GIFT‐Group). Embryos of the In Vivo‐Group and the GIFT‐Group were recovered on day 7 from the oviducts and uterine horns. Embryos of all groups were either cryopreserved at day 7 (day 7 blastocysts) or cultured in vitro in CR1aa‐medium supplemented with 5% ECS for further 24 h and cryopreserved (day 8 blastocysts). The total blastocyst yield found in the in vivo cultured groups was similar to the results of the IVP‐Group. But the appearance of blastocysts was dependent on the duration of in vivo culture. The more time the embryos spent in the in vivo environment, the more blastocysts appeared at day 8. The quality of produced blastocysts assessed by cryo‐survival was also correlated to the culture conditions; the in vivo cultured embryos showed higher cryo‐tolerance. However, the duration of in vivo culture crucially influenced the cryo‐tolerance of produced blastocysts. It is concluded that tubal access is a promising tool to provide a further basis for studying embryo sensitivity to environmental changes. 相似文献
10.
Tahir Karasahin Hasan Alkan Fatma Satilmis Sukru Dursun Huseyin Erdem 《Reproduction in domestic animals》2021,56(12):1555-1561
This study aimed to determine the effect of flunixin meglumine treatment during and after the transfer of in vivo produced embryos to Angus (cows) and Holstein (cows and heifers) breeds of cattle on pregnancy rate. Holstein cows were used as donors in the study. A double dose of prostaglandin F2α was administered to the recipient animals for synchronization. Uterine flushing was performed in donors on day 7 after artificial insemination. A total of 295 transferable embryos were obtained. These embryos were transferred to Angus cows (n = 85), Holstein heifers (n = 80) and Holstein cows (n = 130). After the transfer, these animals were divided into three subgroups. The first subgroup (TI) was administered flunixin meglumine during embryo transfer, and the second subgroup (TII) was administered flunixin meglumine both during embryo transfer and on days 8 and 9 after the transfer. The third subgroup (TIII) was not administered anything and it was considered the control group. Pregnancy examination of the recipients was performed on days 30–35 after the transfer using real-time ultrasonography. The pregnancy rates after embryo transfer were found to be 43.52% in Angus cows, 42.5% in Holstein heifers, and 24.61% in Holstein cows (p < .05). When the animals were not classified according to breed, the pregnancy rates in subgroups TI, TII and TIII were found to be 29.29%, 45.10% and 29.79%, respectively (p < .05). In addition, the pregnancy rates were higher in TII and TIII subgroups of Angus cows and Holstein heifers compared to that of Holstein cows (p < .05). As a result, the pregnancy rates obtained after embryo transfer in Angus cows and Holstein heifers were found to be higher than that in Holstein cows. In addition, it was concluded that the administration of flunixin meglumine during and during/after embryo transfer has a positive effect on pregnancy rates in Angus cows and Holstein heifers. 相似文献
11.
Bielanski A. Simard C. Maxwell P. Nadin-Davis S. 《Veterinary research communications》2001,25(8):663-673
The association of bovine immunodeficiency virus (BIV) with embryos derived by in vitro fertilization from oocytes of experimentally infected heifers or oocytes/embryos exposed to the virus in vitro was investigated. Using a nested-PCR assay, proviral DNA of BIV was not detected in follicular fluid or in embryos derived from BIV-infected donors. In vitro exposure of oocytes to BIV during maturation or insemination with BIV-infected semen resulted in zona pellucida-intact embryos testing negative for BIV provirus. However, exposure of zona pellucida-free day-7 embryos to the virus resulted in a positive BIV assay for 28% of the batches of embryos, suggesting that the zona pellucida has a role in protecting against BIV infection. The presence of BIV in the IVF system had no apparent effect on the development of bovine embryos to the blastocyst stage. 相似文献
12.
13.
Nishigai M 《The Journal of reproduction and development》2003,49(1):23-36
The conditions of embryo transfer by the stepwise method, in which frozen-thawed embryos are transferred on day 7 (day 0=onset of estrus), were investigated with the aim of increasing pregnancy rates in frozen-thawed embryo transfer. The use of a vaginal speculum to prevent bacterial infection when passing an embryo transfer gun through the vagina yielded a pregnancy rate equal to or higher than that with application of a sheath cover to the transfer gun. Administration of a sedative, xylazine, to recipient cattle for preventing movement at the time of embryo transfer improved the pregnancy rate. The influence of the time from thawing of frozen embryos to transfer and of the transportation of the recipient by truck upon pregnancy rate was investigated. Embryo transfer within 60 minutes after aspiration into a straw or transportation of the bovine recipient, 1.5 hours each way before and after transfer, had no influence on pregnancy rate. Relations of the embryonic developmental stage and morphological quality after thawing of frozen embryos to pregnancy rate were investigated in recipients of nulliparous Holstein heifers. The pregnancy rate increased as the embryonic developmental stage advanced from compacted morula, early blastocyst, and blastocyst in that order. The pregnancy rate obtained with blastocyst stage embryos was significantly (P<0.05) higher than that with compacted morula stage embryos, and there was no significant difference in pregnancy rates between excellent morphological quality and good morphological quality for compacted morula stage embryos. When correlation of luteal function and pregnancy rate was investigated in bovine recipients, pregnancy rate showed a tendency to increase with increasing blood progesterone (P) concentration on the day before (on day 6 after estrus) and the day of embryo transfer. The pregnancy rate in bovine recipients, which showed a blood P concentration of > or =2.5 ng/ml on the day before embryo transfer, was significantly (P<0.05) higher than that in those with a blood P concentration of <2.5 ng/ml. Pregnancy rate showed a tendency to increase with decreasing blood estradiol-17beta (E2) concentration on the day of embryo transfer. Activation of luteal function by administration of human chorionic gonadotropin (hCG) in cycling cattle was investigated for its effect on increasing pregnancy rate in bovine recipients. A follicle coexisting with cyclic CL ovulated and induced CL formed after injection of hCG 1,500 IU 5 days after ovulation. The blood P concentration was significantly (P<0.05) higher in the administration group than in the control group, and the blood E2 concentration rapidly decreased, showing a lower concentration than in the control group. These results suggest the possibility that the pregnancy rate could be improved by administration of hCG. Pregnancy rate following intramuscular injection hCG 1,500 IU was comparatively investigated in parous Japanese Black beef cattle receiving frozen-thawed embryos 7 days after estrus. Pregnancy rate was 67.5% in the group in which hCG was administered on day 6 after estrus, and was significantly (P<0.05) higher than that in the control group (45.0%) and the group in which hCG was administered on day 1 after estrus (42.5%), revealing that hCG administration facilitated pregnancy. Transfer of frozen-thawed embryos in the blastocyst stage within 60 minutes after the aspiration into a straw, with a vaginal speculum after administration of xylazine is suggested as a way of improving pregnancy rate in bovine recipients with favorable luteal function and in those with luteal function activated by administration of hCG on the day before embryo transfer. 相似文献
14.
John Maas DVM MS John R. Peauroi DVM MPVM Terry Tonjes BS Julianne Karlonas BS Francis D. Galey DVM PhD Bin Han BVM 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1993,7(6):342-348
Nine recently weaned Hereford heifers were randomly assigned to a control group (n = 3) or a treatment group (n = 6). The animals were selenium (Se) deficient (mean ± SD blood Se concentration = 0.024 ± 0.012 μg/mL). They were maintained on a selenium-deficient diet, and on day 0 of the study the treatment group was given 0.05 mg Se/kg body weight intramuscularly, while the control group received a placebo. The Se concentration of blood, serum, and urine as well as the glutathione peroxidase (GSH-Px) activity of blood and serum was measured over an 84-day period. Peak blood Se and serum Se concentrations (mean ± SD) in the treatment group occurred at 5 hours postinjection and were 0.131 ± 0.028 μg/mL and 0.154 ± 0.027 μg/mL, respectively. The mean blood Se concentration of the treatment group was greater (P < .05) than that of the control group for the first 28 days after injection. The mean serum Se concentration of the treatment group was greater (P < .05) than that of the control group for all times after injection, except for day 56. The mean (±SD) blood GSH-Px activity of the treatment group (12.0 ± 2.3 mU/min/mg hemoglobin) was increased (P < .05) over the control group (2.0 ± 1.4 mU/min/ mg hemoglobin) by day 28 and continued to be greater (P < .05) throughout the 84 day postinjection period. The blood GSH-Px activity and the blood Se concentrations in the treatment group heifers did not reach concentrations considered indicative of Se adequacy (30 mU/min/mg hemoglobin and 0.10 μg/mL, respectively) except briefly, at 5 hours postinjection when the blood Se concentration of the treatment group was 0.131 ± 0.028 μg/mL. The mean serum GSH-Px activity of the treatment group did not differ at any time from that of the control group (P≥ .17). The mean (±SD) fractional excretion (FE) of Se, as an estimate of Se excretion, was greater (P < .05) in the treatment group heifers (n = 5; 6.2 ± 2.5%) than in the control heifers (n = 3; 1.3 ± 0.6%) at 24 hours postinjection. The mean (±SD) weight gain, from day 0 to day 84, for the treatment group heifers was 63.0 ± 18.1 kg and the mean weight gain for the control group heifers was 53.1 ± 7.3 kg at 84 days postinjection and there was no difference between the groups (P < .39). Conclusions drawn from this study include: 1) the increase in blood GSH-Px activity occurs approximately 28 days after Se injection given to Se-deficient heifers, 2) a single label dose of injectable Se does not result in blood Se concentrations or blood GSH-Px activity normally considered to be adequate, 3) the label dose of injectable Se, although therapeutically beneficial for nutritional myodegeneration (NMD), does not seem to be a desired method for long-term Se supplementation of cattle consuming a Se-deficient diet, and 4) blood Se is a better predictor of Se status than serum Se. (Journal of Veterinary Internal Medicine 1993; 7:342–348. Copyright © 1993 by the American College of Veterinary Internal Medicine.) 相似文献
15.
Havlicek V Wetscher F Huber T Brem G Mueller M Besenfelder U 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2005,52(2):94-98
This study was conducted to establish a new approach for in vivo culture of in vitro produced embryos in the bovine oviduct by transvaginal endoscopy. Embryos were in vitro matured, fertilized and cultured for 1-4 days and assigned to groups consisting of 10-30 embryos. Embryos were transferred unilaterally into oviducts of 24 heifers by the means of transvaginal endoscopy. After 3-6 days of in vivo incubation embryos were re-collected. Experiment I aimed to evaluate the capability of embryos to migrate to the uterus. The uterine horns of four animals were flushed first, followed by a combined flushing of both oviducts and uterine horns resulting in collection rates of 31 and 34%, respectively. In experiment II, the transfer of embryos into the oviduct close to ovulation (day 1-2--experiment IIA) or at a more advanced cyclic stage (day 3--experiment IIB) succeeded in the collection of 46 and 34% of the transferred complexes, of which 13 and 37% showed the blastocyst stage. This is the first report of successful recovery of transferable blastocysts by transvaginal endoscopy after tubal in vivo culture in the homologous species of originally in vitro produced embryos. 相似文献
16.
The in vitro effect of bovine viral diarrhea virus (BVDV) on the survival of day 7 to day 7.5 bovine embryos collected from superovulated donors was studied. Fifty-four experimental embryos with the zona pellucida (ZP) intact, damaged or removed were exposed to 1×104 TCD50/ml of the NADL cytopathic strain of BVDC at 37°C for 24 hrs and compared to 36 control embryos that were cultured for 24 hr. Seven embryos with the ZP-removed were similarly exposed for 48 hrs and compared to five control embryos. The overall survival rate was 68% for embryos exposed to BVDV for 24 hrs and 77% for embryos not exposed (P>0.05). Extended exposure of the embryos with the ZP removed to virus for 48 hrs did not affect their survival rate compared to controls. Damage to the ZP by cracking or total removal of the ZP by micromanipulation or acidic Tyrode's solution had no effect on subsequent embryonic survival in the presence of BVDV. It was concluded that exposure to BVDV in vitro is not cytopathic for morula and blastocyst stage bovine embryos over a 48 hr period, even when they are not protected by the ZP. 相似文献
17.
The reproductive organs and fetuses of seven Norwegian Red heifers were investigated for the presence of bovine viral diarrhea virus (BVDV) antigen during the time of initial transplacental transmission of the virus. The heifers were inoculated with a noncytopathogenic BVDV at day 85/86 of gestation and were slaughtered at day 7, 10, 14, 18, or 22 postinoculation (pi). Cryostat sections of uterus, ovaries, placentomes, intercotyledonary fetal membranes, and fetal organs were examined using immunohistochemical techniques. A double immunofluorescence technique was used to identify cells that showed staining with antibodies against the leukocyte common antigen CD45 or the intermediate filament vimentin and BVDV antigens. The earliest stage of infection at which BVDV antigen could be detected in the fetuses was 14 days pi. At this stage, BVDV antigen was detected in cells of mesenchymal origin in the lungs and in large cells that morphologically resembled immature megakaryocytes in the liver. In the intercotyledonary fetal membranes and in the placentomes, BVDV antigen was not detected until 18 and 22 days pi, respectively. BVDV antigen was not detected in maternal tissue from any of the heifers. The present results indicate that fetal infection with BVDV can take place without preceding or simultaneous high concentrations of BVDV in uterus or placenta of acutely infected heifers. 相似文献
18.
Kiyoshi AKIYAMA Jun KOBAYASHI Yoshimasa SATO Ryuichi SATA Megumi OHASHI Emi SASAKI Yorimasa ODA Yoshio OGAWA Shuji UEDA Hisashi NABENISHI Satoko MATOBA 《Animal Science Journal》2010,81(4):461-466
The objective of this study was to develop an in‐straw dilution method suitable for direct transfer of vitrified bovine sexed embryos. Embryo sexing was performed by molecular diagnosis. Several sexed and vitrified‐warmed embryos were transferred after evaluation of morphologically embryonic survival at warming and in‐straw dilution (Evaluation group). The other embryos were immediately directly transferred to recipients without first being expelled from the straws after in‐straw dilution (Non‐evaluation group). The pregnancy rates of vitrified sexed embryos were 38.7% and 34.8% in the Evaluation group and Non‐evaluation group, respectively, which were not significantly different. The viability of lower quality embryos before vitrification tended to be lower (P = 0.087) than that of the higher quality embryos regardless of evaluating embryos after warming and in‐straw dilution. The abortion rates were similar, and there was no difference between the two groups (13.9% and 12.5%, respectively). These results demonstrate that vitrified bovine sexed embryos can be vitrified and diluted by the in‐straw method and that the vitrified and warmed sexed embryos can develop to term. 相似文献
19.
A Cytogenetic Study of Repeat-breeder Heifers and Their Embryos 总被引：1，自引：1，他引：0
King WA Linares T 《The Canadian veterinary journal. La revue veterinaire canadienne》1983,24(4):112-115
Twenty-three Swedish Red and White, Swedish Friesian and crossbred repeat-breeder heifers and 15 day 7 embryos produced by 11 of these heifers were subjected to cytogenetic analysis. Three heifers were found to have abnormal karyotypes; two were heterozygous for the 1/29 translocation, and one was an X-trisomy. Chromosomal anomalies which might account for embryonic death and subsequent repeat-breeding could not be detected in the embryos, however, seven out of the 15 could not be karyotyped due to the lack of cells in metaphase. The possibility of chromosomal anomalies in these embryos could not be ruled out. Three embryos produced by the heifers carrying the translocation were among those which lacked cells in mitosis. Two unfertilized ova were recovered from the X-trisomy heifer suggesting that fertilization failure rather than embryonic death was the cause of repeat-breeding. In the light of this study and similar studies in other species, it is suggested that investigations at earlier stages of development are needed. 相似文献
20.
S Curran R A Pierson O J Ginther 《Journal of the American Veterinary Medical Association》1986,189(10):1289-1294
The bovine conceptus was monitored in 19 heifers by intrarectal ultrasonic imaging from the day an embryonic vesicle was first detected (mean, day 11.7 +/- 0.4; range, days 10 to 17) until detection of the embryo proper (mean, day 20.3 +/- 0.3). Fifteen heifers maintained the conceptus and 4 heifers apparently lost the conceptus. In the heifers that maintained the conceptus, 73% of the embryonic vesicles were classified as spherical (mean diameter, 2.8 +/- 0.2 mm) and 27% were classified as oblong (mean dimensions, 2.0 +/- 0.0 mm and 4.5 +/- 1.0 mm) on the day of first detection. All vesicles were in the uterine horn ipsilateral to the corpus luteum. The vesicles increased in length from the day of first detection. On the average, the vesicle occupied all of the ipsilateral uterine horn on day 16.9 +/- 0.6 and all of the contralateral horn on day 19.6 +/- 0.9. During elongation, the vesicle remained at an approximate height of 2 mm throughout its length, but developed a localized enlargement or bulge on mean day 19.7 +/- 0.2. The embryo proper was detected within the bulge in all 15 heifers. A heartbeat (mean, 188 +/- 4.8 beats/min) was detected on the first day of detection of the embryo proper (8 heifers) or on the following day (7 heifers). The mean length of the interovulatory interval in the 4 heifers that apparently lost the embryonic vesicle was not significantly different from that of nonbred heifers. The vesicles were lost (not ultrasonographically detectable) on days 17 (2 heifers) and 19 (2 heifers).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献