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1.
1. The effects of removal of sub-embryonic fluid and albumen on the development of the fowl embryo were investigated. 2. A deficiency of sub-embryonic fluid on day 7 of incubation resulted in a reduction in the volume of the yolk sac and of allantoic fluid, and a reduction in the mass of the embryo later in incubation. 3. A deficiency of albumen on day 3 of incubation led to a reduction in allantoic fluid and embryo mass after day 12 incubation. 4. The results suggest that the physiology of embryos in unturned eggs is better modelled by eggs deprived of albumen than by eggs deprived of sub-embryonic fluid.  相似文献   

2.
The importance of egg albumen content in whole-body protein synthesis was investigated in developing chicken embryos by using lines genetically selected for high and low albumen contents and by removing albumen from eggs before incubation. 2. Whole-body protein synthesis was estimated by injecting L-[15N]-phenylalanine intravenously on day 12 of incubation. 3. Embryos from high albumen eggs had higher whole-body protein synthesis rates than those from low albumen eggs. 4. Whole-body protein synthesis was reduced by the removal of albumen from eggs before incubation. 5. It was concluded that albumen content per se was of crucial importance in regulating whole-body protein synthesis in chicken embryos during incubation.  相似文献   

3.
1. The present study evaluated developmental characteristics in the chick embryo throughout incubation following cell removal from the freshly laid egg. 2. Between 10 and a few hundred cells of the blastoderm were removed for sex diagnosis. Incubation of the treated embryos was then continued in an open egg shell culture system. 3. Cell recovery from different regions within the blastoderm was performed. 4. The experiments presented here demonstrate the persistence of the developmental potential of chicken embryos in an in ovo culture system after removal of different numbers of cells from the germinal disc prior to incubation. 5. No deviations in developmental characteristics were recorded when compared to untreated control cultures. 6. No detrimental effects of double cell biopsies could be observed. 7. A similar number of chicks developed to hatch regardless of the location of manipulation within the blastoderm.  相似文献   

4.
The teratogenic effect of alcohol on chick embryos has been confirmed by many investigators. However, how this occurs is unknown. The aim of this study was to establish a teratogenic pattern of alcohol effects, on the first stages of development in avians. Fertilized eggs were infused through the air space of the shell on day 0, with ethanol in concentrations of 20%, 40% and 60%. The control group was infused with 0.1 ml of NaCl at 0.9%. At a second stage, the eggs were treated on the 4th day of incubation, using the same method. In both groups the eggs were removed on the 11th day of incubation. The teratological manifestations that appeared more frequently were evisceration, haemorrhagic embryos, oedema, cranial deformities, lack of eyes, and umbilical hernia, showing every embryo a clear reduction in size and body weight.  相似文献   

5.
Strain differences in whole-body protein turnover in the chicken embryo.   总被引:1,自引:0,他引:1  
1. Whether or not there is a strain difference in embryonic whole-body protein turnover rates was tested using the chicken embryos of Rhode Island Red carrying a sex-linked dwarf gene (dwarf), White Leghorn (layer), and White Cornish X White Plymouth Rock (broiler) strains on day 12 of incubation. 2. Whole-body protein synthesis was estimated by injecting L-[15N]-phenylalanine either intraperitoneally or intravenously on day 12 of incubation in order to investigate the effect of the route of isotope administration. The results showed that the values for fractional and absolute synthesis rates were approximately 13% higher by intravenous injection than by intraperitoneal injection. 3. Whole-body protein turnover, both in terms of fractional and absolute rates, was significantly faster in dwarf than in broiler embryos, with intermediate values in layer embryos, although no growth differences were observed on day 12. 4. Difference in egg weight, measured before incubation, did not affect protein turnover. 5. It was concluded that the strain difference manifested in whole-body protein turnover of the chicken embryo would probably be a reflection of differences in genetic background.  相似文献   

6.
An attenuated Derzsy's disease virus strain, designated BAV, was studied in goose embryos. A total of 248 embryonated goose eggs, coming from a susceptible laying flock with no yolk-derived immunity (group I) and from a vaccinated laying flock (group II) were used. The eggs were inoculated into the allantoic cavity with 10(1.9), 10(2.9) or 10(3.9) EID 50/0.2 ml virus on day 12 or day 20 of incubation. Embryos were killed at 5-day intervals. The dead embryos and the hatched goslings (up to 2 weeks of age) were examined by gross and histopathological methods. Reisolation of the virus from the organs was attempted, serum samples were tested for the presence of antibodies, and lymphocytes separated from the circulating blood were used in the lymphocyte stimulation and immunorosette formation tests. Embryos of both groups I and II, inoculated at either time of incubation, showed a body mass gain inferior to that of the controls. Sixteen (group I) and 12 (group II) of the embryos inoculated on day 12 of incubation died. Some (group I: 15, group II: 6) of the embryos inoculated on day 20 of incubation failed to hatch. The pathomorphological changes seen in the embryos killed between days 17 and 22 of incubation were of degenerative character. In embryos killed later (between days 23 and 58 of incubation) the degenerative changes were accompanied by infiltration by inflammatory cells. Reisolation of the virus strain was mostly successful between postinoculation (PI) days 5 and 10. Specific virus-neutralizing antibodies and cellular immune response were demonstrable already at hatching.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

7.
A commercially available rapid inoculum standardization system (RISS) was compared to the broth inoculum standardization method (BIS) for antimicrobial susceptibility testing of bacterial isolates from the bovine mammary gland. Overall agreement between RISS and the BIS method was 95.9%. RISS bypasses the 2-8 h incubation period required by BIS, thus providing antimicrobial susceptibility test data in a more timely manner. RISS was determined to be an acceptable alternative method to the BIS method for preparation of standardized inoculum for antimicrobial susceptibility testing of bovine mammary gland isolates.  相似文献   

8.
The onset of ossification centres of the pectoral girdle and wing skeleton of the quail (Coturnix coturnix japonica) has been studied in embryos and juvenile birds, which were sampled daily from the 4th day of incubation up to the 12th day after hatching. Specimens, which were cleared and were stained with Alcian Blue and Alizarin Red S, were examined at the stereomicroscope. The furcula ossified with intramembranous ossification at the 7th day of incubation. The first centres of perichondral ossification in the scapula and the coracoid bones were observed at the 7th day of incubation. In the humerus, radius and ulna, perichondral ossification was observed at the 6th day of incubation. The carpal bones were ossified between the 8th and 10th day of the post-hatching period. The 2nd metacarpal bone began to ossify at the 6th day of the post-hatching period, whereas the 3rd and 4th metacarpal bones were ossified at the 7th day of incubation. At the 9th day of incubation, ossification was observed in the 1st phalanx of the alular digit and in the phalanges of the major digit. The 2nd phalanx of the alular digit began to ossify at the 12th, whereas the phalanx of the minor digit at the 14th day of incubation. The data presented here provide useful baseline information on the normal sequential pattern of ossification in the pectoral girdle and wing skeleton in this species.  相似文献   

9.
1. A total of 39,000 eggs (260 incubation batches) produced by Hybro, Cobb and Ross were studied. They were transferred from incubators to hatchers at day 15,16,17 or 18 of incubation. 2. Hatchability increased in proportion to the day of transfer and it was higher when the transfer occurred at day 18, whereas the differences between hatchability for days 15, 16 and 17 were not significant. 3. The hatchability of the Hybro eggs was more affected by the transfer time, as were the eggs of the older flock (51 weeks and more). 4. The percentage of unhatched embryos increased with the age of the breeders and decreased with the day of transfer. In addition, the percentage of unhatched embryos was affected by the strain of hen. 5. It was concluded that transfer time has to be considered in order to optimise hatchability and chick quality, especially if the eggs from older flocks are incubated.  相似文献   

10.
Attention is drawn to the need of the cytotoxic testing of instruments used in the process of the transfer of early embryos. It was demonstrated by spermiotoxic test that some instruments were very toxic to bull sperm and may, analogically, threaten the life of embryos. The new catheters Foley Barum, produced by the Optimit Corporation and developed in recent time, are highly compatible with bull sperm: a slight reduction of sperm motility (by 5.7%) occurred only after 90 minutes of incubation. Teflon embryonation capillaries had a similar behaviour. The introduction of biologically compatible materials in the process of embryo transfer contributed to a substantial improvement of embryo survival: 63.01% of animals (46) got in calf after 68 bloodless transfers.  相似文献   

11.
The purpose of this work was to determine the individual and combined effects of insecticide Sumithion 50 EC (50% fenitrothion) and herbicide Fusilade S (12.5% fluazifop-P-butyl) on the development of pheasant embryos. Eggs were treated by injection of various concentrations of pesticides into the air space on day 12 of incubation. Pathological examination of embryos was carried out on day 23 of the hatching period. Mortality rate, body weight data and morphological alterations were evaluated after the macroscopic examination. The skeletal staining method was used to detect deformities. The two pesticides used in combination moderated the toxic/teratogenic effects of individual treatment.  相似文献   

12.
On day 9 or 12 of the hatching period different pesticides (parathion, methyl-parathion, carbendazim, 2,4-D-amine Na, phosmethylane) were applied in ecotoxicological trials. The formulations were either injected into the air space of pheasant, quail or hen eggs or hen eggs were treated by the immersion technique. The residues of pesticides were measured in samples on days 13, 14 and 16 of incubation of chicken and pheasant embryos, while the Japanese quail embryos were analysed on days 10-14 of incubation. Analytical chemistry data showed a varying degradation rate of the compounds in avian embryos of the same species. The residues directly affect the embryos, disturbing their normal development and causing pathophysiological and morphological changes.  相似文献   

13.
Day 7 bovine embryos were microsurgically bisected and replaced into surrogate zonae pellucidae. They were fixed immediately after bisection and at various intervals of in vitro incubation at 35 °C in modified Dulbecco's medium. At the light microscopical level, the bisected embryos restored the prebisection morphology within 30 min. after splitting. The electron microscopy confirmed these findings, suggesting that day 7 bovine demi-embryos for transfer purposes, should be cultured for 30 min before morphologically evaluated. Eleven pairs of bisected day 7 bovine embryos were transferred to 11 synchronized heifers. The recipient heifers were slaughtered at day 15, and the recovered embryos evaluated. Nine of the demi-embryos developed to morphologically, normal spherical to elongated, embryos.  相似文献   

14.
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   

15.
Parthenogenetic development was found in 16.7 per cent of 934 Beltsville Small White turkey eggs in 1952. This development, occurring during incubation, was chiefly of an unorganised type, blood or embryos being encountered only on rare occasions. In 1954, a selective breeding programme was initiated which was designed to intensify this trait. This has resulted in marked yearly increases in the average level of parthenogenetic development. Since 1952 there has been a three‐fold increase in the overall incidence of parthenogenesis and presently 45 per cent of all unfertilised eggs incubated can be expected to undergo development to some extent. The most marked increases have come in the number of eggs giving rise to well‐formed embryos. At the present time from 12–13 Per cent of all eggs can be expected to contain embryos, representing a 65‐fold increase over the level found in eggs of the original stock. Corresponding increases have likewise occurred in embryo viability. The few embryos encountered before 1954 rarely attained the size of a normal 5–6 day embryo. During the last three years approximately 34 per cent of all parthenogenetic embryos lived for 21 days or longer and 7 of every 100 of them emerged or were helped from the shell on the 29th or 30th day of incubation. One hundred and six parthenogenetic poults were hatched from 10,060 eggs in 1961, 94 from 8519 eggs in 1962, and 23 from 5906 eggs in 1963.

About 25 per cent of the parthenogenetic poults which have hatched survived to maturity. Some of these have produced semen containing viable spermatozoa. More than 25 parthenogenetic males thus far have demonstrated their ability to sire offspring.  相似文献   


16.
Skeletal chondrofication, ossification and growth of turkey embryos were investigated and analysed to enable assessment of the developmental status and evaluation of the experimental effects on skeletal development, skeletal mutations and development of cultured embryos. Ten embryos were prepared every 24 h from 8 to 28 days of incubation. The fixed embryos were cleared and stained in toto with Alcian blue & Alizarin red for cartilage and ossified components, respectively. Observation of the skeleton was performed under a stereoscopic microscopy, with special attention to the timing of chondrofication and ossification of the bones. The first occurrence of the primary ossification centres was observed in the femur, tibiotarsus, and the dentary and supra-angular of the mandible on the 12th day, followed immediately by the other long bones. Skeletal features of the skull were determined to show the latest appearance of cartilage and ossification. Hence, all elements of the hyolingual apparatus remained cartilaginous until hatching took place except for the ceratobranchial. Even though the vertebral column chondrified earlier as compared with the ribs and sternum, they ossified later. While chondrofication was present in all the regions of the vertebral column at the same time, ossification progressed from the cervical through caudal regions. The growth rate of the femur was eminently higher than that of the humerus with increase in time, particularly after the 20th day of incubation. This seems to be obviously natural because the eggs used in the study are from the broiler turkey, which gains giant muscle mass at a very short period; precocity is probably at the expense of the bones of the leg rather than those of the wing.  相似文献   

17.
The purpose of our work was to establish an efficient-oriented enucleation method to produce transgenic embryos with handmade cloning (HMC). After 41–42 h oocytes maturation, the oocytes were further cultured with or without 0.4 μg/ml demecolcine for 45 min [chemically assisted handmade enucleation (CAHE) group vs polar body (PB) oriented handmade enucleation (OHE) group respectively]. After removal of the cumulus cells and partial digestion of the zona pellucida, oocytes with visible extrusion cones and/or polar bodies attached to the surface were subjected to oriented bisection. Putative cytoplasts without extrusion cones or PB were selected as recipients. Two cytoplasts were electrofused with one transgenic fibroblasts expressing green fluorescent protein (GFP), while non-transgenic fibroblasts were used as controls. Reconstructed embryos were cultured in Well of Wells (WOWs) with porcine zygote medium 3 (PZM-3) after activation. Cleavage and blastocyst rates were registered on day 2 and day 7 of in vitro culture respectively. Meanwhile, the total blastocyst cell number was counted on day 7. We found that the difference was only observed between blastocyst rates (38.6 ± 2% vs 48.1 ± 3%) of cloned embryos with GFP transgenic fibroblast cells after CAHE vs OHE. With adjusted time-lapse for zonae-free cloned embryos cultured in WOWs with PZM-3, it was obvious that in vitro developmental competence after CAHE was compromised when compared with the OHE method. OHE enucleation method seems to be a potential superior alternative method used for somatic cell nuclear transfer (SCNT) with transgenic fibroblast cells.  相似文献   

18.
1. Chick embryos, obtained from the anterior portion of the magnum of the oviduct 60 to 80 min after the preceding egg had been laid, were cultured in vitro in small and large recipient eggshells until hatching.

2. Of 82 embryos cultured, 46.3% had survived to day 4 of incubation, and 19.5% survived to hatching.

3. The method for culturing embryos used in this experiment could facilitate research on the in vitro manipulation of early chick embryos.  相似文献   


19.
Chicken infectious anemia virus (CIAV) is a ubiquitous and highly resistant virus of chickens that causes anemia and death in chicks less than 3 wk of age and immunosuppression in chickens older than 3 wk of age. The production of specific-pathogen-free eggs free of CIAV is essential for research and vaccine production. Currently, flocks are screened for CIAV by antibody tests to ensure freedom from CIAV infection. Recent evidence, however, indicates that chickens may carry and vertically transmit CIAV DNA independently of their antibody status. In this study, we tested embryos and eggshell membrane residues by nested polymerase chain reaction (PCR) as a sensitive method of detecting CIAV DNA. CIAV DNA could be detected in the blastodisks and semen obtained from antibody-positive and -negative chickens. Examination of different tissues between 18 and 20 days of incubation indicated that many but not all organs of individual embryos were positive. The lymphoid organs and gonads had the highest incidence of CIAV DNA, which was significantly different (P < 0.05) from the incidence in the liver. Eggshell membrane samples from embryos or newly hatched chicks were an excellent noninvasive source for the detection of CIAV DNA, identifying significantly more positive embryos than did pooled lymphoid organs. The use of dexamethasone injections as a method to improve the detection of carrier birds did not result in an increase of vertical transmission or cause seroconversion in the treated hens. A combination of testing eggshell membrane residues at hatch and periodic testing of blood DNA by nested PCR can be used to identify chickens carrying CIAV DNA and may be used to eradicate carrier birds.  相似文献   

20.
We investigated whether suckling would affect embryo production of cows bred by timed artificial insemination (TAI) following an ovulation synchronization protocol combined with ovum pick-up and progesterone releasing intravaginal device (OPU-PRID-TAI protocol). The number of oocytes and transferable embryos collected by repeated OPU, performed before and after TAI, were recorded. A total of 14 Japanese Black cows were divided into weaned (n=7) and suckled groups (n=7). All 14 cows were treated with OPU on day 0 (the first day of treatment) and then with a PRID for 9 days. Prostaglandin F(2alpha) analog was administered on day 7, GnRH analog was administered on day 10 (36 h after removal of the PRID) and TAI was performed 12 h later. Ovulation was confirmed by palpation per rectum the following day. After TAI, additional OPU sessions were performed on days 18, 25 and 32. The synchronized ovulation rates of the weaned and suckled groups were 100 and 85.7%, and the conception rates were 71.4 and 42.9%, respectively. Immature oocytes were fertilized and cultured in vitro. The numbers of oocytes collected and blastocysts generated were similar between the individual OPU sessions in both groups. However, the total numbers of oocytes collected, cultured oocytes, cleavage embryos and blastocysts as well as the proportions of cleavage embryos and blastocysts to cultured oocytes were all significantly (P<0.05) greater in the weaned group compared with the suckled group. These results suggest that the OPU-PRID-TAI protocol has the potential to produce a significant number of good-quality embryos in vitro after repeated OPU in early postpartum weaned Japanese Black cows. To collect more oocytes and produce more embryos, we suggest that calves be removed from cows scheduled for treatment using this protocol.  相似文献   

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