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1.
To study the effect of donor age on oocyte developmental competence and steroid profiles, the crossbred cow (Murray Grey × Brahman) in Yunnan province of China were selected and divided into three groups according to its age. The three groups were young cows (n = 12; 12 months old), middle‐aged cows (n = 15; parity: ≤3 calvings; age: 7–8 years old) and old cows (n = 10; parity: ≥8 calvings; age: ≥15 years old). Cumulus–oocyte complexes (COCs) were collected by 10 consecutive ovum pick up (OPU) sessions with a 4‐day interval between each session, followed by in vitro maturation, fertilization and embryo development. Results showed that cleavage rates (CR) and blastocyst rates (BR) were higher in the young cows than those in the middle‐aged and old cows (p < 0.05). CR and BR from COCs of the first and the fourth OPU sessions were lower than those from other sessions in the young cows and the middle‐aged cows (p < 0.05), whereas the similar phenomenon was not observed in the old cows. Plasma concentrations of oestradiol were higher, and plasma concentrations of progesterone were lower before and during OPU sessions in the young cows compared with those in the same period in the middle‐aged cows or the old cows (p < 0.01). In conclusion, donor age of oocytes could affect developmental competence of oocytes recovered by OPU through the action of steroid hormonal balance on follicle development.  相似文献   

2.
The effects of frame size (FS) and body condition score (BCS) on performance of Brahman cows were evaluated using records collected from 1984 to 1994 at the Subtropical Agricultural Research Station, Brooksville, Florida. Age at puberty (AP), calving rate (CR), calving date (CD), survival rate (SR), weaning rate (WR), birth weight (BWT), weaning weight (WWT), preweaning ADG, and kilograms of calf produced per cow exposed (PPC) were obtained from first- (n = 215), second- (n = 130), and third or greater-parity (n = 267) dams. Based on hip height at 18 mo of age, heifers were assigned to three FS groups: small (115 to 126 cm), medium (127 to 133 cm), or large (134 to 145 cm). Small and medium FS heifers attained puberty at younger (P<.05) ages (633.2+/-12.3 and 626.4+/-12.0 d) than large FS heifers (672.3+/-17.1 d). Calving rate in large FS second-parity dams was 27% less (P<.05) than in small and medium FS dams. In third or greater-parity dams, CR was greater (P<.05) for small FS cows than for medium and large FS cows. Across the three parity groups, CR improved with increasing BCS. Except for the first-parity dams, animals with better fall BCS calved earlier (P<.05). In first-parity dams, SR was less (P<.01) in large (47.9+/-11.0%) than in small (80.7 +/-5.2%) and medium (83.4+/-4.7%) FS groups. Weaning rates of large FS first- and second-parity dams were less (P<.05) than those of small and medium FS dams. Second-parity dams with BCS 3 had lower (P<.05) WR than dams with BCS 4 and 5. Within first- and third or greater-parity dams, BWT of calves born to small FS cows were the lightest, and those born to large FS dams were the heaviest; those born to medium FS dams were intermediate (P<.05). In second-parity dams, BWT of calves of large FS dams were greater (P<.05) than those of small and medium FS dams. In first-parity dams, calves weaned by small FS cows had lower (P<.05) WWT than those weaned by higher FS cows. In the third or greater-parity group, large FS dams weaned heavier calves (P<.05) than other dams. In all parity groups of dams, calves out of large FS cows had greater ADG (P<.05) than those from small and medium FS cows. In first-parity dams, PPC was comparable between small and medium FS dams, but both tended to be greater (P<.10) than PPC of large FS dams. Small and medium FS females reached puberty at an earlier age, calved earlier, and had greater calving, survival, and weaning rates, as well as greater kilograms of calf produced per cow exposed than the large FS females. As the large FS cows matured, they seemed to have overcome the negative effects imposed by FS that were observed at younger ages. Their performance traits were generally all comparable to those of smaller cows once they had reached maturity.  相似文献   

3.
The effect of source of cumulus-oocytes-complexes (COCs), maturation and fertilization conditions on developmental competence of dromedary embryos was examined. Thirty-six adult females were superovulated with equine Chorionic Gonadotropin (eCG) injection (3500 IU, IM) and divided in three groups of 12 females each. Group 1 provided 138 COC's collected from follicles >or= 5 mm 10 days after stimulation prior hCG treatment and matured in vitro for 30 h. Group 2 provided 120 in vivo matured oocytes which were aspirated from their follicles 20 h after hCG (3000 IU, IV) given on day 10 follow eCG injection. Group 3 provided 65 in vivo matured/fertilized oocytes. Females in Group 3 received hCG on day 10 following eCG treatment and then were mated 24 h later. Fertilized oocytes were collected from the oviducts of females 48-h post-mating. Quality of the oocytes was assessed after in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro culture (IVC) of COCs. All cultures were performed in three replicates (n = 3) at 38.5 degrees C, under 5% CO(2) and high humidity (>95%). Only COCs with cumulus and homogenous (dark) cytoplasm were used. Nuclear maturation rate for Groups 1 and 2 was determined by epifluorescence microscopy in a sample of COCs (n = 30) denuded, fixed and stained with Hoechst 33342. To study the viability of obtained embryos, hatched blastocysts from each group were transferred to recipients followed by pregnancy diagnosis using ultrasonography at 15, 60 and 90 days. The percentage of COCs reaching metaphase II (MII) after 30 h of maturation was slightly but not significantly higher for in vivo matured oocytes (28/30; 93%) than those in vitro matured (25/30; 84%). The total rate of cleavage (2 cells to blastocyst stage) was not different for the three groups. However, significantly (p < 0.05) more blastocyst and hatched blastocysts were obtained from in vivo matured and in vivo fertilized oocytes (Group 3; 52% and 73%) than from in vitro fertilized oocytes whether they were matured in vitro (Group 1; 35% and 32%) or in vivo (Group 2; 32% and 45%). Pregnancy rates were not significantly different amongst all groups for the three first months following embryo transfer. All pregnancies were lost after day 90 follow transfer except for in vivo matured and in vivo matured/fertilized groups. Only in vivo matured/in vitro fertilized and in vivo matured/fertilized produced embryos continued normal development until term and resulted in the birth of normal and healthy live calves. Six claves (29%; 6/21) were born from Group 3 and one (8%; 1/13) calf was born from Group 2. This study shows that the IVC system used is able to support camel embryo development. However, developmental competence and viability of dromedary embryos may be directly related to the intrinsic quality (cytoplasmic maturation) of oocytes.  相似文献   

4.
This work was designed to evaluate the ovarian follicular development, oocytes morphology, methods of oocytes reterival, and the effect of different in vitro maturation (IVM) media on cumulus cell expansion and nuclear maturation of Jennies oocytes. Experiment 1, the number of small (<6 mm), medium (6 to 9 mm) and large size (>10 mm) ovarian follicles was recorded. Cumulus-oocyte-complexes (COCs) were reterived and classified into 4 Grades based on their cumulus-cells investment and the homogenous of the ooplasm. In Experiment 2, COCs were recovered by using 18-G, 20-G needle or slicing and scraping of ovarian follicles to determine the number and morphology of the recovered COCs. In Experiment 3, Grade A and B COCs were IVM in DMEM-HG, DMEM-LG, DMEM-F12, TCM199, TCM199-F12 or CR1aa media supplemented with 10 % FCS?+?10 μg FSH/mL?+?10 IU hCG/mL?+?50 μg/mL gentamicin. Maturation was performed for 36 h at 38.5 °C under 5 % CO2 in humidified air. After IVM, cumulus cell expansion and oocytes nuclear canfiguration were determined. An average of 6.40?±?0.26 follicles was recorded per Jenny ovary, representing 3.37?±?0.46, 1.89?±?0.14 and 1.14?±?0.16, for the small, medium and large size follicles, respectively. Oocyte recovery was higher (P?P?P?P?P?P?P?P?Conclusion: Slicing and scraping or aspiration of follicles using 18-G needle increased the number and percentage of Grade A Jennies oocytes. TCM199-F12, CR1aa and TCM199 medi are more suitable for IVM of Jenny oocytes by promoting cumulus cells expansion and nuclear maturation to M II stage.  相似文献   

5.
The relationship between the peripheral concentrations of estradiol-17β (E(2)) and the preovulatory characteristics of cumulus oocyte complexes (COCs) during superovulation treatment was investigated in Japanese Black cows. A superovulation regimen with FSH treatment in a descending manner was commenced on day 7 (n=3) or day 10 (n=2) of the estrous cycle (day 0=estrus). Peripheral blood was collected to measure E(2) concentrations twice a day throughout the treatment. Ovariectomies were performed at 100 h after the initial FSH treatment in five cows. Every follicle more than 8 mm in diameter was isolated from the ovaries, and cumulus-oocyte complexes (COCs) were gently aspirated. The COCs were then separated into three groups based on the characteristics of the cumulus (compact, expanded and denuded) and subgrouped based on the stage of the nucleus in the oocytes (GV, GVBD). Plasma E(2) concentrations tended to increase gradually and reached the peak level at around 84 h (E(2)-84: n=3) or 96 h (E(2)-96: n=2) after the initial FSH treatment. The ratio of COCs with expanded cumulus was significantly higher in E(2)-84 than in E(2)-96 (P<0.01). However, there was no difference in the ratio of oocytes showing GVBD between E(2)-84 and E(2)-96 (P=0.73), and the characteristics of the cumulus did not affect the stage of the nucleus in the oocytes in either groups (compact, expanded and nude; P=0.61, 0.81 and 1.00). It was possible that the time until the peak plasma E(2) concentrations after the FSH treatment could become an indicator for the maturation of follicles and oocytes in preovulatory follicles during superovulation treatment in Japanese Black cows.  相似文献   

6.
Very small follicles (<3.0 mm diameter) are over‐represented on the surface of ovaries of non‐cycling pigs, and the oocytes collected from these follicles generally have reduced developmental competence in vitro. This study examined the effect of follicle size on the nuclear maturation (n = 608), the potential of parthenogenetic activation (n = 243) and the cyclic AMP (cAMP) content of pre‐pubertal porcine oocytes (n = 480). In addition, the influence of follicle size on steroid hormone synthesis was analysed. Cumulus oocyte complexes (COCs) flushed from small (2.5–4.0 mm) or large (4.5–6.0 mm) ovarian follicles were cultured for 0, 28 and 46 h. After 46 h of IVM, a greater proportion of oocytes from 4.5‐ to 6.0‐mm follicles reach metaphase II (MII) compared with those from follicles with 2.5–4.0 mm of diameter (96.1 vs 77.0%, respectively; p < 0.001). Parthenogenetic activation of oocytes from large follicles produced higher developmental rates than oocytes from large follicles (p < 0.05). At 28 h, the IVM medium with oocytes from large follicles contained significantly more 17ß‐oestradiol (E2) than the medium with oocytes from small follicles (5.55 vs 3.45 ng/ml, respectively; p < 0.05) and at 46 h, the medium with oocytes from small follicles contained significantly more progesterone (P4) than the medium with oocytes from large follicles (276.7 vs 108.2 ng/ml, respectively, p < 0.05). Porcine oocytes from large follicles have higher nuclear and cytoplasmic maturation capacities, but the differences did not appear to be cAMP‐mediated. Our findings also suggest that COCs from small follicles undergo more intensive luteinization than COCs from large follicles. The results show that oocytes from follicles with a diameter greater than 4.0 mm are more suitable for in vitro studies.  相似文献   

7.
This study investigated the viability of embryos from non-stimulated 2-3-month-old calves generated in vitro using oocytes from follicles of defined size in terms of their ability to produce full-term pregnancies. Ablation of follicles>or=4 mm was used to induce the emergence of a new follicular wave, and calves (n=3) were laparoscopically punctured three times at 7-day-intervals to recover cumulus-oocyte-complexes (COCs) from follicles>8 (group A) and between 4-8 mm (group B). Calves were aged 49, 56, and 80 days, respectively, at first recovery. Morphologically intact COCs were subjected to in vitro maturation, fertilization, and embryo culture, and compact morulae/blastocysts were transferred on day 7 post-insemination to synchronized virgin heifers. Blood typing was used for maternity analysis. A total of 29 COCs were recovered, 21 cultured, yielding 11 cleaved embryos (52.4%) and 6 compact morulae/blastocysts (28.6%). No differences were observed between groups. Transfer of the 6 embryos to 5 recipients resulted in three pregnancies (one from group A and two from group B). Two normal male offspring (both from group B), with birth weights of 44 and 51 kg, were born, and two donor calves, aged 56 and 59 days, were identified as the dams. In conclusion, the results demonstrate that embryos generated in vitro from oocytes from non-stimulated calves at an age younger than two months are viable in terms of their ability to produce full-term pregnancies, and suggest that the viability of calf embryos is not related to follicle size.  相似文献   

8.
Our objective was to determine whether oocyte integrity is compromised when oocytes are recovered from progestogen-induced persistent follicles. Beef cows were presynchronized using PGF2alpha (PGF). Cows detected in estrus after PGF were assigned to either NOR (one 6-mg norgestomet implant for 10 d starting on d 16 of cycle; day 0 = estrus; n = 112) or CON (control, no implant [n = 128] and presynchronized 8 d later than NOR). All cows received 25 mg of PGF at the end of treatment (NOR, d 26; CON, d 18). Treatments produced persistent preovulatory follicles (NOR) or normal preovulatory-size follicles (CON), which were measured via ultrasonography 1 d before slaughter. Ovaries were collected from all animals (NOR, d 27; CON, d 19) along with random (RAN) ovaries from cattle slaughtered on the same days. Cumulus oocyte complexes (COC) were aspirated from the preovulatory follicles with recovery rates of 63% across treatments. Small follicles (2 to 7 mm diameter) from NOR, CON, and RAN cows were also aspirated to recover COC. Preovulatory follicles were larger (19.5+/-.9 vs. 13.6+/-.4 mm, P<.05), serum P4 was lower (.4+/-.1 vs. 3.9+/-.2 ng/mL, P<.05), and serum E2 was higher (28.7+/-1.6 vs. 7.6+/-.8 pg/mL, P<.05) in NOR than in CON cows. Cumulus oocyte complexes recovered from preovulatory follicles (62 NOR, 64 CON) were matured, fertilized, and cultured in vitro for comparison of embryonic development. A subset (24 NOR, 34 CON) of COC were assigned morphological quality grades. A separate set of recovered COC (10 NOR, 15 CON) was fixed within 1 h after recovery for assessment of the stage of meiosis. Treatments did not differ for oocyte quality grade or stage of meiosis. However, COC from NOR cows had more layers of cumulus cells (P<.05), and more of those COC had undergone cumulus expansion (29.2 vs. 5.9%, P<.05 for NOR vs. CON, respectively). Development of cleaved embryos to the morula and blastocyst stages from preovulatory follicles (22.6% NOR, 18.9% CON) or small follicles (42% NOR, 40% CON, 42% RAN) did not differ with treatment. Oocyte quality and in vitro developmental competence were not compromised for oocytes from induced persistent follicles compared with oocytes from normal preovulatory follicles. Increased expansion of cumulus cells associated with oocytes from progestogen-induced persistent follicles may be relevant to the reduction of in vivo fertility associated with such follicles.  相似文献   

9.
Two experiments were conducted to determine whether milking beef cows two or five times daily in the presence or absence of their own nonsuckling calves would alter postpartum interval to first ovulation. Multiparous Angus x Hereford cow-calf pairs were assigned randomly between 13 and 18 d postpartum to treatments for 4 wk. In Exp. 1, pairs were assigned to six treatments: 1) calf was weaned permanently from its dam (CW; n = 9); 2) same as CW, but dam was milked twice daily (CW+2xM; n = 9); 3) calf was present continuously with its dam but restricted from contact with the udder (CR; n = 9); 4) same as CR, but dam was milked twice daily (CR+2xM; n = 9); 5) same as CR, but calf was allowed to suckle twice daily (CR+2xS; n = 8); and 6) calf was present continuously with its dam and suckled ad libitum (CP; n = 9). The interval from onset of treatments to first postpartum ovulation was shorter (P<.05) in the CW (14.1+/-3.1 d), CR (14.2+/-3.1 d), CW+2xM (13.0+/-3.1 d), and CR+2xM (17.2+/-3.1 d) than in the CP (34.7+/-3.1 d) and CR+2xS (33.9+/-3.3 d) treatments. Daily milk yield during treatment was greater (P<.01) for CR+2xM cows (7.1+/-.6 kg) than for CW+2xM cows (3.5+/-.6 kg). In Exp. 2, cow-calf pairs were assigned to three treatments: 1) CR+2xM (n = 10); 2) same as CR+2xM but cows were milked five times daily (CR+5xM; n = 10); or 3) CP (n = 10). The interval to first postpartum ovulation was shorter (P<.05) in the CR+2xM (23.6+/-3.5 d) and CR+5xM (26.1+/-3.7 d) treatments than in the CP (37.7+/-3.7 d) treatment. Daily milk yield during treatment was greater (P<.05) for CR+5xM cows (7.7+/-.6 kg) than for CR+2xM cows (6.4+/-.6 kg) by 17%. We conclude that suckling twice daily was sufficient to prolong postpartum anestrus as much as suckling ad libitum. Furthermore, milk removal by suckling, but not by milking two or five times daily, even in the presence of the cow's own nonsuckling calf, is essential to prolong postpartum anovulation.  相似文献   

10.
The availability of cow ovaries from the slaughterhouse has been very limited in Taiwan. To maximize the use of cow ovaries for research purposes, whole ovary dissection was performed and the developmental competence of the oocytes derived from different sizes of follicles was assessed by the rates of in vitro maturation (IVM) and parthenogenetic activation of the oocytes in Experiment 1 (Exp 1). Cumulus-oocyte complexes (COCs) derived from small (1-2 mm) and large (3-8 mm) follicles were subjected to standard IVM culture for 24 h. Mature oocytes were selected and then parthenogenetically activated using A23187 (5 microm, 5 min) or thimerosal (200 microm, 10 min) alone or combined with 6-dimethylaminopurine (2.5 mm and 3.5 h, respectively). Activation rates of the oocytes, neither from the large nor small follicles, were affected by different activation treatments (single or combined stimuli). Whereas maturation rates for the oocytes from large follicles were superior to those from small follicles in both the single (59% vs 45%) and combined treatments (76% vs 40%; p < 0.05). To understand how prolonged heat shock (HS) influences cytoskeletal configurations of mature bovine oocytes, in Experiment 2 (Exp 2), matured oocytes derived from large follicles were randomly allocated to different durations of HS treatments at 41.5 degrees C for 0 (C0h, control, n = 12), 1 (HS1h, n = 28), 2 (HS2h, n = 31), and 4 h (HS4h, n = 30). An additional control group was cultured for 4 h without HS (38.5 degrees C, 4 h, n = 35). Alterations in nuclear structures, microtubules (MTs), and microfilaments (MFs) of the oocytes were examined. Abnormalities in the chromosomes, spindle MTs and the percentages of oocytes with cytoplasmic MTs increased with time of HS treatment. The intensity of the MF distribution in the HS oocytes was also altered. Significant changes in the cytoskeleton after HS may be associated with the reduced development under hyperthermia and, perhaps, with the low pregnancy rates of the animals during hot seasons.  相似文献   

11.
输卵管和颗粒细胞单层对牛体外受精胚胎发育的影响   总被引：2，自引：1，他引：2  
以屠宰场牛卵巢为试验材料,研究输卵管细胞单层(OCM)和颗粒细胞单层(GCM)对牛卵母细胞体外成熟(IVM)、体外受精(IVF)和体外培养(IVC)后胚胎发育能力的影响。(1)从卵泡抽取卵丘卵母细胞复合体(COCs),并根据卵母细胞外面卵丘细胞的层数将其分为3类:1级(≥4层);2级(2～3层);3级(0～1层)。作分别在IVM和IVC培养液中添加GCM(1×106个/mL)与不添加的对比试验。结果显示:添加GCM对1级卵母细胞的卵裂率、6～8细胞发育率和囊胚率无明显影响(P>0.05);但添加GCM的2级、3级卵母细胞,受精后的卵裂率、6～8细胞发育率和囊胚率分别高于未添加组(P<0.05)。(2)所有卵母细胞(包括COCs和裸卵)被随机分为3个组,在其IVM和IVC培养液中分别添加OCM、GCM或不添加体细胞(对照组)。结果显示:OCM和GCM组的卵裂率、6～8细胞发育率和囊胚率均高于对照组(P<0.05),而两试验组之间差异不显著。  相似文献   

12.
牦牛卵巢卵母细胞体外培养成熟条件的建立   总被引：2，自引：2，他引：2  
研究了不同采集方法和不同培养液对牦牛卵母细胞体外成熟的培养效果。结果:在牦牛乏情期,每个卵巢平均回收卵数为(9.33±4.30),可用卵数为(5.63±4.19)。将牦牛卵丘卵母细胞复合体分别置于5种成熟培养液中培养,成熟率分别为75.56%、71.11%、81.33%、77.33%和77.78%,卵裂率分别为42.22%、33.33%、49.33%、46.67%和42.22%,其中C的成熟液效果最好。来自卵巢表面卵泡的COCs的成熟率(81.33(vs69.33(,P>0.05)高于来自卵巢内卵泡的COCs,卵裂率(49.33%vs34.67%,P<0.05)显著高于来自卵巢内卵泡的COCs。来自明亮卵泡的COCs的成熟率(81.33%vs33.33%,P<0.01)和卵裂率(49.33%vs3.33%,P<0.01)极显著高于来自混浊卵泡的COCs。  相似文献   

13.
This study aimed to evaluate gonadotropin secretion and the developmental competence of follicular oocytes in dairy cattle during the early postpartum (PP) period. The number of follicles developed after transvaginal ultrasound-guided ovum pick-up (OPU) and fertilizability of retrieved oocytes were compared between cows in which the first dominant follicle (DF) ovulated (ovulated group, n=4) and did not ovulate (non-ovulated group, n=3), and between early PP (early PP group, n=2) and after the resumption of the estrous cycle (cyclic group, n=2). Follicular ablation was performed 2-4 days after the detection of DF in the second follicular wave PP. OPU was repeated 3-5 times at 3 or 4-day intervals from 3-4 days after the follicular ablation. At OPU, the follicles were enumerated and all those > or = 5 mm in diameter were aspirated. Recovered oocytes were subjected to in vitro maturation and fertilization. Both criteria were similar between ovulated and non-ovulated groups, and between early PP and cyclic groups. These results suggest that FSH/LH secretions required for follicle recruitment and subsequent follicular growth during the early PP period are similar to those after resumption of the estrous cycle. They also indicate that follicular oocytes during the early PP period have developmental competence.  相似文献   

14.
A 2 x 2 factorial study evaluated effects of cow wintering system and last trimester CP supplementation on performance of beef cows and steer progeny over a 3-yr period. Pregnant composite cows (Red Angus x Simmental) grazed winter range (WR; n = 4/yr) or corn residue (CR; n = 4/yr) during winter and within grazing treatment received 0.45 kg/d (DM) 28% CP cubes (PS; n = 4/yr) or no supplement (NS; n = 4/yr). Offspring steer calves entered the feedlot 14 d postweaning and were slaughtered 222 d later. Precalving BW was greater (P = 0.02) for PS than NS cows grazing WR, whereas precalving BCS was greater (P < 0.001) for cows grazing CR compared with WR. Calf birth BW was greater (P = 0.02) for CR than WR and tended to be greater (P = 0.11) for PS than NS cows. Prebreeding BW and BCS were greater (P 0.32) by PS. Calf weaning BW was less (P = 0.01) for calves from NS cows grazing WR compared with all other treatments. Pregnancy rate was unaffected by treatment (P > 0.39). Steer ADG, 12th-rib fat, yield grade, and LM area (P > 0.10) were similar among all treatments. However, final BW and HCW (P = 0.02) were greater for steers from PS-WR than NS-WR cows. Compared with steers from NS cows, steers from PS cows had greater marbling scores (P = 0.004) and a greater (P = 0.04) proportion graded USDA Choice or greater. Protein supplementation of dams increased the value of calves at weaning (P = 0.03) and of steers at slaughter regardless of winter grazing treatment (P = 0.005). Calf birth and weaning BW were increased by grazing CR during the winter. Calf weaning BW was increased by PS of the dam if the dam grazed WR. Compared with steers from NS cows, steer progeny from PS cows had a greater quality grade with no (P = 0.26) effect on yield grade. These data support a late gestation dam nutrition effect on calf production via fetal programming.  相似文献   

15.
A类卵母细胞在mTCM 199、NCSU2 3和NCSU37体系中培养 4 4～ 5 2小时后 ,成熟率分别为 76 .1%、78.1%和 6 5 .2 %。前两者差异不显著 (P >0 .0 5 ) ,但显著高于后者 (P <0 .0 5 )。卵母细胞在添加eCG和hCG的NCSU2 3体系中的成熟率 (75 .6 % )明显高于添加FSH的LH和成熟率 (6 5 .2 % ) (P <0 .0 5 )。A、B、C三类卵母细胞在NCSU2 3的成熟率分别为 73.3%、6 0 .4 %和 11.0 % ,三者间差异显著 (P <0 .0 5 )。大 (ф >6mm)、中 (ф =3～ 6mm)和小 (ф <3mm)三种卵泡中的卵母细胞在NCSU2 3中培养后 ,成熟率分别为 5 6 .2 % ,78.1%和 5 1.9% ,中等卵泡中卵母胞的体外成熟率显著高于其他两组 (P <0 .0 5 )。  相似文献   

16.
A 2-year comparative study was carried out to evaluate the effect of ovary size, follicle size and oocyte quality of 3-month-old Simmental calves and the efficiency of using calf ovaries in an in vitro fertilization (IVF) programme. We evaluated the effects of different concentrations of follicle-stimulating hormone (FSH) and oestradiol-17beta (E-17beta) in the maturation medium on the in vitro development of calf oocytes into morula and blastocysts. The proportion of recovered oocytes (62.1%; 42.8%; 25.3%) and the percentage of good quality cumulus oocyte complexes (84.2%: 59.8%; 45.9%) decreased significantly (P < 0.01) with decreasing ovary size (L, M and S). The rates of two or more cells on Day 2 and of blastocysts on Day 7 and Day 9 were significantly lower (P < 0.01) for calf oocytes (61.5%; 18.9%: 15.9%) compared with those from sexually matured females (70.1%: 32.3%; 22.2%). Calf oocytes. matured in medium supplemented with 20 microg/ml or 10 microg/ml FSH plus 2 microg/ml E-17beta had higher rates of cleavage on Day 2 (64.1% and 64.7%) and blastocysts on Day 7 (24.5% and 22.4%) than the control supplemented with 10 microg/ml FSH (55.6% and 19.2%, respectively). Groups supplemented with 20 microg/ml FSH plus 2 microg/ml E-17beta and 10 mg/ml plus 4 mg/ml E-17beta showed a significantly lower developmental rate of blastocysts on Day 7 (14.6% and 14.5%). High concentrations of E-17beta (4 microg/ml) resulted in a significantly lower development of blastocysts on Day 9 (8.1%) and hatched blastocysts on Day 13 (3.5%) (P < 0.01). We conclude that the proportion of calf oocytes obtained from immature animals and their suitability for IVF are lower than those of cows. Thus, the use of oocytcs from sexually immature females would decrease the relative efficiency of IVF programmes. Supplementation with high concentrations of FSH can improve the maturation and developmental capacity of oocytes from prepubertal calves.  相似文献   

17.
旨在探讨玻璃化冷冻-解冻对牦牛未成熟卵母细胞发育能力及卵丘-卵母细胞复合体（COCs）转录组的影响，为完善牦牛COCs冷冻保存技术提供理论依据。本研究将未经成熟培养的牦牛COCs进行玻璃化冷冻-解冻后分为2组，A组：COCs体外成熟（IVM）后用普通牛精子进行体外受精（IVF），获得的受精卵在G-1胚胎培养液中培养72 h后转入G-2培养液培养96 h；B组：IVF后，受精卵在G-1培养液培养120 h后转入G-2培养液培养48 h；以未进行冷冻处理的新鲜COCs作为对照组（C组）：IVF后，受精卵在G-1培养液培养72 h后转入G-2培养液培养96 h。对牦牛新鲜COCs（n=3）和玻璃化冷冻-解冻的COCs（n=3）进行扩增、建库和转录组测序（RNA-seq）分析。结果发现，B组的卵裂率、囊胚率显著高于A组（P<0.05），但A组和B组的卵裂率、囊胚率均显著低于C组（P<0.05）。以|log2（fold change）|≥ 2，Q<0.05为阈值，牦牛冻融COCs相对于新鲜COCs共筛选出851个差异表达基因（DEGs），其中上调846个，下调5个。GO分析表明，DEGs主要富集于生物过程、细胞组分和分子功能3大类；KEGG注释结果表明，DEGs富集到258条通路，其中16条通路显著富集（P<0.05）。研究表明，IVF后在G-1培养液中培养120 h可以提高牦牛玻璃化冷冻卵母细胞的后续发育能力；玻璃化冷冻影响牦牛COCs转录组，从而降低卵母细胞的发育潜力。该发现为完善牦牛COCs玻璃化冷冻技术提供了一定的理论基础。  相似文献   

18.
The present study was conducted to examine the supplemented effect of cumulus cell masses (CCMs) derived from middle follicle (MF; 3–6 mm diameter) on the morphology and the meiotic or developmental competence of oocytes from small follicles (SF; 1–2 mm diameter). The number of cumulus cells surrounding oocytes just after collection was also lower in cumulus–oocyte complexes (COCs) from SF than MF. The ooplasmic diameter of oocytes was significantly smaller in SF‐derived oocytes than MF‐derived ones before and after in vitro maturation (IVM), whereas the diameter significantly increased during the culture. Co‐culture of SF‐derived COCs with MF‐derived CCMs during IVM significantly improved the meiotic competence of the oocytes to the metaphase‐II stage. Furthermore, the ooplasmic diameter of SF‐derived COCs during IVM was increased to the similar size of MF‐derived those in the presence of MF‐derived CCMs. The abilities of oocytes to be penetrated, to form male pronuclear formation and to cleave or develop to the blastocyst stage were not affected by the co‐culture with CCMs. Electrophoretic analysis of CCM secretions clearly showed the presence of more protein(s) approximately 27.6 kDa in the conditioned medium when supplemented with MF‐derived CCMs. In conclusion, we demonstrate that supplementation with MF‐derived CCMs improves the ooplasmic diameter and meiotic competence of SF‐derived oocytes.  相似文献   

19.
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20.
The objectives of this study were to evaluate replacing GnRH with hCG and the effects of 48-h calf removal (CR) on pregnancy rates of cows synchronized with the CO-Synch protocol. Suckled beef cows (n = 467) at two locations were assigned to treatment by breed, age, and calving date. Treatment included either GnRH with (n = 121) or without CR (n = 117) or hCG with (n = 115) or without CR (n = 114) using the CO-Synch protocol. On d 0 and 9, cows received either hCG (2,500 IU, i.m.) or GnRH (100 microg, i.m.), and on d 7 all cows received PGF2alpha (25 mg). At one location, blood samples were collected from all cows (n = 203) on d -14, -7, 0, 7, 9, and 16. Calves were removed on d 7 and returned on d 9 (48 h) from approximately half of the cows that received GnRH or hCG. Cows that were detected in estrus between d 6 and 9 were bred approximately 12 h later and received no further injections. Cows not observed in estrus by d 9 received a second injection of either GnRH or hCG and were timed-inseminated. The AI pregnancy rates for GnRH-treated cows with or without CR and hCG-treated cows with or without CR were 46, 49, 35, and 34%, respectively (P = 0.44). Pregnancy rates of cows differed by treatment x age interaction (P = 0.07), hormone (P = 0.09), and hormone x age (P = 0.01) but not by CR (P = 0.66) or CR x age (P = 0.33). Among 2-yr-olds, pregnancy rates were higher for cows treated with hCG without CR than for cows that received GnRH with calf removal, whereas cows treated with hCG with CR and GnRH without CR were intermediate. In addition hCG-treated 2-yr-olds had higher pregnancy rates than GnRH-treated 2-yr-olds regardless of calf presence, but the reverse was true for older cows. Overall, GnRH-treated cows (48%) had a higher (P = 0.09) pregnancy rate than hCG-treated cows (34%). Among anestrous cows, GnRH and hCG were similar (P = 0.40) in their ability to induce ovulation and corpus luteum formation after the first and second injections of GnRH (31 and 76%, respectively) or hCG (39 and 61%, respectively). More (P = 0.001) hCG-treated cows exhibited short estrous cycles following timed AI. We conclude that hCG is not a suitable replacement for GnRH to synchronize ovulation with the CO-Synch protocol in multiparous cows, although further evaluation among primiparous cows is warranted using hCG with the CO-Synch protocol.  相似文献   

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