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1.
The effects of pregnant mare serum gonadotrophin (PMSG) dose and PMSG antiserum on superovulation in crossbred beef cows were studied. In experiment I, three groups were treated with 1200, 2400 or 3600 IU of PMSG and 48 h later with prostaglandin (PGF). The mean numbers of corpora lutea (CL), unovulated follicles, and total ova/embryos collected increased as the PMSG dose increased. The percent of fertilized ova and transferable embryos was lowest in the highest dose group (p < 0.05). In experiment II, all cows received 2500 IU of PMSG; groups 1 and 2 were treated with sheep anti-PMSG serum at 48 h or 60 h after PGF; group 3 cows were PMSG-only controls. The number of CL was lowest and the number of unovulated follicles highest in the PMSG-only group (p < 0.05). The number of CL was higher in group 2 (anti-PMSG at 60 h) than in the control group, with the anti-PMSG at 48 h not different from the other groups. Numbers of total ova/embryos, fertilized ova, and transferable embryos were higher (p < 0.05) in both antiserum-treated groups relative to the PMSG-only group. We conclude that superovulation of beef cows with PMSG and treatment with PMSG antiserum will induce a higher superovulatory response and will result in higher CL numbers and fewer unovulated follicles. Further, the variability in the superovulatory response to PMSG treatment was still evident when PMSG antiserum was administered.  相似文献   

2.
This study investigated the activity of beta-N-acetyloglucosaminidase (beta-NAGASE), alpha-mannosidase, and beta-galactosidase in the uterine luminal fluid of cows after superovulation treatment, along with the possible associations between the activity of these 3 glycosidases and the superovulatory response. Embryos and a sample of fluid flushed from each uterine horn were collected on day 7 after artificial insemination (on estrus day 0) from 32 cows in which superovulation was induced with porcine follicle-stimulating hormone. Glycosidase activity was assayed colorimetrically. The cows were classified as to superovulatory response according to the number of corpora lutea per ovary (group 1, 1 to 4; group 2, > 4) and according to the total number of embryos per horn (T1, 0; T2, 1 to 2; T3, 3 to 4; T4, > 4) and the number of transferable embryos per horn (TR1, 0; TR2, 1 to 2; TR3, 3 to 4; TR4, > 4). The mean activity of beta-NAGASE was significantly lower (P < 0.05) in group 2 than in group 1, at 95.99 (standard error 20.43) versus 226.72 (46.77) IU/L. It was also significantly lower (P < 0.01) in group T4 compared with groups T1, T2, and T3, at 50.09 (8.21) versus 129.25 (34.60), 222.27 (62.62), and 290.26 (93.77) IU/L, respectively, as well as in group T1 compared with group T3. There was a positive relationship between beta-NAGASE activity and both the total number of embryos (P = 0.047) and the number of transferable embryos per horn (P = 0.013) when 1 to 4 corpora lutea developed per ipsilateral ovary. No difference in alpha-mannosidase or beta-galactosidase activity was detected among the groups.  相似文献   

3.
The effect of active immunization against inhibin on the response to superovulatory treatment by porcine FSH (pFSH) was investigated in cattle. Japanese black cows were sc injected with 1 mg of porcine inhibin alpha-subunit fragment (1-26) conjugated with rabbit serum albumin (inhibin-immunized group; n=14) or rabbit serum albumin alone (control group; n=12) in Freund's complete adjuvant. Booster injections (half the amount of the primary injection) were given 35 and 70 days after the primary injection. All cows were superovulated three times with pFSH. Three days after each injection of the antigen, a progesterone-releasing intravaginal device (CIDR-B) was inserted vaginally into all animals and left in place for 10 days. Forty-eight hours before CIDR-B removal, all animals were sc injected with 30 mg pFSH dissolved in 40% polyvinylpyrrolidone, and im injected with 750 microg of PGF2alpha at CIDR-B removal. Cows were artificially inseminated twice during estrus, and ova or embryos were collected 7 or 8 days after estrus. The number of corpora lutea, the number of ova or embryos and the number of transferable embryos in inhibin-immunized cows (12.1+/-1.2, 11.1+/-1.3 and 6.2+/-1.0, respectively) were significantly greater than those in the controls (8.2+/-1.0, 5.7+/-1.1 and 3.1+/-0.7, respectively). These results indicate that active immunization against inhibin enhanced ovarian response to the usual superovulatory treatment in cattle. Therefore, immunization against inhibin may be a useful approach for improving the response to superovulation in cattle.  相似文献   

4.
The objective of this study was to investigate the relationship between the plasma concentrations of vitamin A (VA), vitamin E (VE) and β-carotene (BC) during embryo collection in Japanese Black cows that had undergone superovulation treatment and the embryo collection results. Following superovulation treatment in 116 Japanese Black cows, we collected 1317 embryos by nonsurgical means seven days after artificial insemination. The collected embryos were classified into transferable embryos, unfertilized oocytes and degenerated embryos. After embryo collection, we collected blood samples from the cows and measured the plasma concentrations of VA, VE and BC. The cows were then divided into 2 groups depending on the plasma concentration of VA (L and H: < 80 IU/dl and ≥ 80 IU/dl), VE (L and H: < 150 μg/dl and ≥ 150 μg/dl) and BC (L and H: < 150 μg/dl and ≥ 150 μg/dl). As a result, the number of collected embryos in the H group of VE was significantly (P<0.01) higher than that in L groups. Furthermore, the number of transferable embryos was higher (P<0.05) in all VA, VE and BC H groups than in the L groups. The H group for BC showed a high ratio of transferable embryos compared with the L group (P<0.05). Consequently, the present study suggests that the plasma VE and BC concentrations are positively correlated with the embryo collection results.  相似文献   

5.
The postpartum uterine bacteriology, histology, resumption of ovarian activity and polymorphonuclear granulocyte (PMN) number and function in 18 Swedish dairy cows were studied. Cows were milked either 2x (n = 9) or 3x per day (n = 9). Endometrial biopsy samples for bacteriological and histological investigations were collected during 8 weeks postpartum, starting within one week after calving. Milk samples for progesterone determination were collected twice a week until the cows had shown normal reproductive cyclicity. Blood samples for granulocyte function (phagocytic capacity and total number) were collected from each animal on the same days as when the biopsies were obtained. All animals in both groups were free from bacteria at the latest after 6 weeks post-partum and there was no difference regarding bacterial elimination and bacterial species between milking groups. No difference regarding uterine histology between milking groups was seen. In both groups, 8 cows had normal to slight infiltration of leukocytes in the endometrium at the end of sample collection. No changes in granulocyte function could be seen in the 2 milking groups. Resumption of ovarian activity was detected on day 45.6 +/- 9.3 (mean +/- SD) postpartum in the 2x milking group and 36.6 +/- 9.0 (mean +/- SD) post-partum in the 3x milking group (p = 0.05). Based on our findings, an increased milking frequency from 2 to 3 times a day did not influence the uterine function postpartum.  相似文献   

6.
The objective of this study was to investigate the effect of dosage and number of days of follicle stimulating hormone (FSH) treatment on superovulatory response in controlled internal drug release (CIDR)-treated Korean native cows. Forty cows underwent two superovulatory treatments with a crossover design. Cows, at random stages of the estrous cycle, received a CIDR together with injections of 1 mg estradiol benzoate and 50 mg progesterone, and gonadotropin treatment began 4 days later. The cows were divided into 2 groups based on the dosage and number of days of treatment with porcine FSH; a total of 28 mg FSH was given in twice daily intramascular injections in decreasing doses over 4 days (5, 5, 4, 4, 3, 3, 2 and 2 mg; T1 group, n=20) or a total of 24 mg FSH was given in twice daily decreasing doses over 3 days (5, 5, 4, 4, 3 and 3 mg; T2 group, n=20). This was followed by the alternate treatment in the subsequent superovulation. The cows were treated identically in all other respects. PGF(2alpha) (25 mg and 15 mg) was given with the 5th and 6th injections of FSH, CIDR were withdrawn at the 6th FSH injection and the cows received 200 microg GnRH 36 h after CIDR withdrawal. The cows were artificially inseminated twice, at 48 and 60 h after CIDR withdrawal, using commercial semen from four Korean native bulls, and embryos were recovered 6 or 7 days after the 2nd insemination. The numbers of corpora lutea (CL; 7.9+/-1.0 vs. 8.3+/-1.1) and large follicles (1.2+/-0.2 vs. 1.3+/-0.3) present at the time embryo recovery, as detected by ultrasonography, did not differ between the T1 and T2 groups (P>0.05). Similarly, the numbers of total ova/embryos (6.2+/-0.9 vs. 6.4+/-1.1), transferable embryos (3.4+/-0.8 vs. 3.2+/-0.7), degenerate embryos (0.8+/-0.2 vs. 1.0+/-0.3) and unfertilized ova (2.1+/-0.5 vs. 2.2+/-0.5) did not differ between the groups (P>0.05). These data indicate that a reduced dose (24 vs. 28 mg) and number of treatments (6 vs. 8) of FSH for superovulation of CIDR-treated Korean native cows does not affect the embryo yield.  相似文献   

7.
PMSG-PG (1), PMSG-PG-anti-PMSG (2), and FSH-PG (3) were used under production conditions for superovulation treatment of high-yielding cows. An analysis of results has shown the FSH variant (3) to be superior with significance to the other two regimes. It yielded positive ovarian reactions (greater than or equal to 3 corpora lutea) in 92.0 percent of all cases, with 7.0 +/- 6.3 transferable embryos being obtained. Regime 1 gave only 75.5 percent as well as 3.2 +/- 2.97, while 85.5 percent and 4.3 +/- 3.9 were recorded from regime 2. Significance amounted to P less than 0.01; 0.001. Regimes 2 and 3 in standardised form are recommended for embryo transfer with cattle in breeding practice.  相似文献   

8.
AIM: To evaluate the efficacy of a programme using oestradiol benzoate, progesterone and the prostaglandin-F2 (PG) analogue, cloprostenol, to synchronise oestrus and ovulation in dairy cows, compared with a programme using a gonadotropinreleasing hormone (GnRH) agonist, buserelin, and cloprostenol. METHODS: Twenty non-lactating dairy cows, at random stages of the oestrus cycle, were randomly assigned to 1 of 2 treatments. In Treatment 1 ( OPPG; n=10), cows were injected with 2 mg oestradiol benzoate intramuscularly (IM) plus 200 mg progesterone subcutaneously (SC) on Day 0, followed by 500 microg cloprostenol IM on Day 9 and 1 mg oestradiol benzoate on Day 10. In Treatment 2 (GPG; n=10), cows were injected with 10 microg buserelin IM on Day 0, 500 microg cloprostenol IM on Day 7 and 10 microg buserelin on Day 9. The ovaries of all cows were examined by ultrasonography, using an 8 MHz probe, from 5 days before the initial treatment until ovulation. Cows were observed for oestrus 3 times daily for 7 days after cloprostenol treatment. Blood samples were collected daily for determination of progesterone, and 6-hourly for 36 h after the second oestradiol or buserelin injection for the determination of follicle stimulating hormone (FSH) and luteinising hormone (LH) concentrations. RESULTS: The percentage of cows observed in oestrus was higher in the OPPG group than in the GPG group (100% vs 55.6%, p=0.018). Treatment with either short-acting progesterone plus oestradiol benzoate or buserelin was followed by atresia or ovulation of the dominant follicle. Emergence of a new follicular wave occurred earlier (p>0.001) in the GPG group (2.2+/-0.2 days) than in the OPPG group (3.6+/-0.2 days). There was no significant difference between treatment groups in the variation of time of follicular wave emergence or size of the largest follicles at either the time of initial treatment (10.8+/-1.4 mm vs 11.1+/-0.8 mm), cloprostenol treatment (13.8+/-0.7 mm vs 14.0+/-1.3 mm) or of ovulation (15.4+/-0.7 mm vs 17.6+/-1.1 mm; p=0.10). The LH surge occurred sooner after the second injection of buserelin (4.0+/-1.0 h) than after the second injection of oestradiol benzoate (22.8+/-1.2 h; p>0.001). The interval between the second injection of oestradiol benzoate or buserelin and ovulation did not differ significantly between treatment groups (1.7+/-0.3 days vs 1.6+/-0.2 days; p=0.69). CONCLUSIONS: The use of short-term progesterone treatment, combined with oestradiol benzoate for follicular wave synchronisation, and cloprostenol to cause lysis of residual luteal tissue, is a promising alternative to established methods of oestrus synchronisation in cows.  相似文献   

9.
The aim of this study was to evaluate whether an additional intramuscular (im) injection of pFSH would increase the embryo production in zebu cows superovulated with a single subcutaneous (sc) pFSH injection. Twenty‐one Nelore cows were treated with a progesterone vaginal implant (Controlled Internal Drug Relased – CIDR B®) and injected im with 2.5 mg estradiol benzoate. Four days later, cows were assigned randomly into three groups and superovulated with pFSH. Groups A and B received single sc injections of 400 and 320 IU, respectively; Group C received multiple im injections of 400 IU in decreasing doses at 12‐h intervals over 4 days. In the morning (07:00 am) of day 3 after starting superovulation, cows received im 150 mcg cloprostenol and Group B was additionally injected im with 80 IU of pFSH. CIDR‐B was withdrawn in the afternoon (07:00 pm). Cows were inseminated 48 and 62 h after the cloprostenol injection. Embryo collection and corpora lutea (CL) estimation were done 7 days after insemination. Alternation of treatments (crossover design) occurred at a 60‐day interval. There was no significant difference (p > 0.05) of CL counts among treatments. The total (transferable and no transferable) number of recovered embryos from Group A (6.9 ± 1.5) was not different from Group C (9.8 ± 1.2), whereas Group B (5.7 ± 1.5) was lower than Group C (p < 0.05). The number of transferable embryos from Groups A (2.4 ± 0.7) and B (1.7 ± 0.6) was lower (p < 0.05) than Group C (4.6 ± 1.2). Lesser (p < 0.05) embryo production from Group B was related to lower recovery rate (46.4%), compared with Groups A (65.1%) and C (81.7%). It was concluded that an additional im subdose of pFSH, injected 48 h after a single subcutaneous (sc) dose of pFSH, does not improve the embryo production in zebu cows.  相似文献   

10.
Mastitis-induced ovarian abnormalities were studied in a field trial. At 1-3 day after calving, > or = 2 parity cows not affected with chronic recurrent mastitis and yielding < 400,000/ml somatic cell count (SCC) individual milk in the previous lactation, were enrolled in the study. Thereafter milk samples were collected three times weekly for 95-100 day for progesterone (P4) assay. Individual P4 profiles were used to monitor ovarian cyclicity. When mastitis was diagnosed in the first 80 day post-partum (pp), clinical signs were recorded and scored, and aseptic milk samples were taken to identify the mastitis pathogens. Depending on the isolated pathogens the cows were blocked into one of the three sub-groups affected by either Gram-positive (GP), or Gram-negative (GN) bacteria, or of those with no detected pathogens (NDP). Cows suffering from any type of mastitis between days 15 and 28 (n = 27) showed a delay in the onset of ovarian cyclicity, and estrus was postponed compared to cows affected during the first 14 day pp (n = 59) and controls (n = 175) (38.6 +/- 2.3 vs 33.4 +/- 2.1 and 32.0 +/- 1.0 day, respectively, for onset of ovarian cyclicity and 90.7 +/- 2.5 vs 80.2 +/- 2.8 and 83.9 +/- 2.1 day, respectively, for estrus; both p < 0.05). The percentage of cows ovulating by day 28 was lower in those affected by mastitis between days 14 and 28 compared to cows between days 1 and 14 and controls (22.2% vs 47.5 and 50.3%, respectively; p < 0.05). A significantly higher rate of premature luteolysis was observed in GN + NDP compared to GP mastitis and healthy cows (46.7% vs 8.3 and 2.0%, respectively; p < 0.001). If the mastitis outbreak occurred during the follicular phase, the duration of this cycle segment was lengthened in GN + NDP mastitis compared to GP mastitis and healthy cows (10.8 +/- 0.9 vs 7.9 +/- 0.1 and 7.2 +/- 0.1, respectively; p < 0.001). The results indicate that mastitis can affect the resumption of ovarian activity in pp dairy cows. Mastitis may also impair reproduction also in cyclic cows: this effect can be the consequence of premature luteolysis or a prolonged follicular phase.  相似文献   

11.
In this study, the effect of serum paraoxonase-1 (PON-1) activity on superovulation response and embryo yield was evaluated. The study material comprised 50 Holstein cows aged 3–4 years on postpartum day 90–120 with a body condition score of 3–3.25. A progesterone-based estrus synchronization protocol was initially administered to the selected donors. For this purpose, progesterone source was inserted intravaginally (day 0) and gonadotropin-releasing hormone injection was performed (day 6). Seven days after the insertion of progesterone device, follicle-stimulating hormone injections (total dose of 500 µg in decreasing doses for 4 days) were administered for superovulation. On the morning of the ninth day, prostaglandin (PG) F2α was administered, and the progesterone device was removed from the vagina in the evening on the same day. Two days after PGF2α administration, fixed-time artificial insemination was performed in the morning and in the evening. On the day of artificial insemination, blood samples were taken from the donors to determine the serum PON-1 activity. Uterine flushing was performed seven days after insemination. The results revealed that the serum PON-1 activity (mean ± SD, 562.71 ± 140.23 U/l) of the cows that responded to superovulation (donors with total corpus luteum count of ≥3 in both ovaries) was higher than those (389.91 ± 80.51 U/l) that did not (P<0.05). On the day of insemination, a positive correlation was determined between serum PON-1 activity and the counts of total corpus luteum (r=0.398), total oocyte/embryo (r=0.468), transferable embryo (r=0.453), and Code I embryos (r=0.315, P<0.05). Unlike the Code I embryos, there was no significant correlation between serum PON-1 activity and the number of Code III embryos. Moreover, no significant difference in the number of Code III embryos between the two PON-1 groups was observed. However, embryo yield and quality were found to have increased with increased PON-1 activity. Therefore, it was concluded that serum PON-1 activity may be associated with superovulation response, embryo yield and quality in donor cows.  相似文献   

12.
The clinical effectiveness of FSH-P for initiating superovulation in cattle was examined in 948 animals of the breed Deutsche Schwarzbunte and Deutsche Rotbunte of RPN Verden during 1988 and 1989. In the group of the FSH-P treated animals the number of transferable embryos was 4.4 +/- 4 per animal. The 25% percentile was 1 and the 75% percentile was 7 transferable embryos per donor. In 88 animals no embryos were found. In animals with a large number of embryos there was a changed quotient between transferable embryos and non transferable embryos per animal. A seasonal dependence in the number of transferable embryos was not found. Repeated treatment with FSH-P seemed to have no influence on the number of transferable embryos per animal. In the dose range between 6.6-9.4 mg FSH-P no differences in the number of transferable embryos per animal were found.  相似文献   

13.
Effects of age of cow and a norgestomet (N) implant on number of embryos and endocrine responses to induction of superovulation were studied in old (greater than 12 yr) and young (5 to 7 yr) lactating beef cows. Seventeen cows (8 old and 9 young) received a 6-mg N ear implant on d 4 or 5 of the cycle (d 0 = estrus); the remaining 17 cows (9 old and 8 young) served as untreated controls (C). All animals were treated with 38 mg of porcine follicle-stimulating hormone (FSH-P) in decreasing dosages over a 4.5-d period beginning on d 10 or 11. Regression of the corpus luteum was induced with injections of PGF2 alpha at 0800 and 2000 on d 4 of FSH-P treatment; implants were removed at the second injection of PGF2 alpha. Cows were inseminated artificially 12 and 24 h after onset of estrus. Embryos were collected on d 7 or 8 postinsemination. Blood samples were obtained daily at 0800 from 2 d prior to initiation of treatment with FSH-P until collection of embryos. An additional sample was collected each day at 2000, from the first injection of PGF2 alpha to 1 d after onset of estrus. Samples were assayed for luteinizing hormone (LH), progesterone (P4), follicle stimulating hormone (FSH) and estradiol-17 beta (E2). Total number of embryos plus ova recovered was lower (P less than .01) in N-treated (5.2 +/- 1.1) than in C-treated (10.6 +/- 1.6) cows.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

14.
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   

15.
The effect of gonadotropin releasing hormone (GnRH) supplement was investigated in twenty eight FSH-treated buffalo cows. Animals were assigned to three groups; Group I: GnRH was given at standing heat (n=9), Group II: GnRH was given 8-12 hr after standing heat (n=8) and Group III: Control group with FSH alone (n=11). The responses (no. of corpora lutea and no. of anovulatory follicles), the number of recovered embryos and transferable embryos among the three groups were compared following slaughter of the animals on days 6 to 7 after first mating. The results indicated that the application of GnRH in FSH-treated animals gave no advantage by increasing in the number of ovulations or recovered embryos in all the treatment groups (P>0.05): 4.33 +/- 3.35 vs 3.88 +/- 4.09 vs 4.5 +/- 2.68 for corpora lutea, and 2.33 +/- 2.24 vs 2.0 +/- 3.20 vs 1.91 +/- 2.74 for recovered embryos respectively. GnRH treatment tended to reduce the number of anovulatory follicles but the finding was not significant; 6.11 +/- 3.3 vs 7.38 +/- 4.84 vs 10.18 +/- 2.74 follilcles (P>0.05). The supplementation of GnRH at 8-12 hr after standing heat seemed to produce more transferable embryos than those of treated at standing heat or the controls 1.63 +/- 2.77 vs 1.25 +/- 1.67 vs 1.36 +/- 1.69 embryos respectively.  相似文献   

16.
The objective of this study was to determine the effect of genotype and week postpartum on serum concentrations of IGF-I, body condition score (BCS), BW, and ovarian function in beef cows. Cows from the following genotypes were utilized in two consecutive years: Angus (A x A; n = 9), Brahman (B x B; n = 10), Charolais (C x C; n = 12), Angus x Brahman (A x B; n = 22), Brahman x Charolais (B x C; n = 19) and Angus x Charolais (A x C; n = 24). Serum concentrations of IGF-I, BCS, and BW were determined between wk 2 and 9 postpartum. Rectal ultrasound was used to determine days postpartum to first medium (6 to 9 mm) and first large (> or = 10 mm) follicle. Averaged across genotype, BCS decreased (P < 0.05) from 5.0 +/- 0.1 on wk 3 to 4.8 +/- 0.1 on wk 6 postpartum, and BW decreased (P < 0.05) between wk 2 and 3 and again between wk 4 and 9 postpartum. Averaged over year and week postpartum, serum IGF-I concentrations were greatest (P < 0.05) in B x B cows (46 +/- 5 ng/mL) compared with all other genotypes; lowest in A x A (12 +/- 4 ng/mL), C x C (13 +/- 4 ng/mL), and A x C cows (18 +/- 3 ng/mL); and intermediate (P < 0.05) in A x B (28 +/- 3 ng/mL) and B x C (26 +/- 3 ng/mL) cows compared with all other genotypes. Serum IGF-I concentrations did not change (P > 0.10) with week postpartum in C x C, A x A, and A x C cows, but increased (P < 0.05) between wk 2 and 7 postpartum in B x C, A x B, and B x B cows. Average interval to first medium (16 +/- 2 d) and first large (35 +/- 2 d) follicle did not differ (P > 0.10) among genotypes. Serum IGF-I concentrations correlated with BCS (r = 0.53 to 0.72, P < 0.001) but not with days to first large follicle (r = -0.19 to -0.22, P > 0.10). Averaged across genotypes, cows that lost BCS postpartum had lower (P < 0.01) serum IGF-I concentrations. Cows that calved with adequate BCS (i.e., > or = 5) had greater (P < 0.01) serum IGF-I concentrations postpartum than cows that calved with inadequate BCS (i.e., < 5) but days to first large and medium follicle did not differ (P > 0.10). In conclusion, concentrations of IGF-I in serum differed among genotypes and were associated with BCS but not days to first large or medium follicle in postpartum beef cows.  相似文献   

17.
《中国牛业科学》2022,48(5):17-21
[目的]为进一步研究核心群奶牛超数排卵技术影响因素。[方法]试验使用3个FSH剂量和4 个公牛精液对27头青年奶牛进行超数排卵。对供体牛胚胎生产情况和受体胚胎移植妊娠率进行统计。[结果]结果显示供体2次超排获得7.8枚平均可用胚胎显著高于1次超排获得的5.7枚平均可用胚胎(P<0.05);260,280 mg FSH超排供体获得6.0和7.7 枚平均可用胚胎显著高于300 mg FSH超排供体获得的4.6枚平均可用胚胎(P<0.05);供体使用4个公牛精液人工授精后获得的平均可用胚胎数和平均未受精卵数差异不显著(P>0.05);移植前接种疫苗的受体胚胎移植妊娠率显著降低(P<0.05）。[结论]核心群奶牛超排适宜FSH剂量为260-280 mg,使用高受精力公牛精液和对超排反应好的供体重复超排能够提高超排效率,受体移植前避免疫苗接种能够提高胚胎移植妊娠率。  相似文献   

18.
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   

19.
为了研究季节对石家庄地区荷斯坦奶牛超数排卵的影响,对达到12月龄的荷斯坦育成牛逐月进行3次超数排卵。结果表明,头均胚胎总数和头均退化胚胎数各月差异不显著(P>0.05);头均可用胚胎数量3月最高(7.04±4.92),8月最低(3.20±3.33),两者间差异显著(P<0.05),与其它各月间无显著差异。总体而言,超排效果随着气温升高而呈下降的趋势,在气候较为适宜奶牛生理生存状态的季节,超排效果更为理想。说明超数排卵效果春季最好,秋冬季效果好于夏季,超排应避开夏季炎热的月份。  相似文献   

20.
旨在研究供体牛超数排卵（简称超排）过程中不同时间外周血AMH浓度与荷斯坦青年奶牛体内胚胎生产效率的相关性,优化供体牛筛选标准,提高荷斯坦青年奶牛体内胚胎生产效率。本试验共选用96头荷斯坦青年奶牛进行超排处理,分别在孕酮阴道栓（CIDR）埋置、人工授精和胚胎回收当天通过尾根采集外周血检测抗缪勒管激素（anti-Müllerian hormone,AMH）浓度,将不同时期的外周血AMH浓度按照高（浓度分布最高的25%）、中等（浓度分布中间的25%~75%）、低（浓度分布最低的25%）分为3组,并检验了这3组之间头均回收胚胎数、头均可用胚胎数、头均退化胚胎数和头均未受精数等指标间的差异。结果表明：1）外周血AMH浓度检测结果显示,从CIDR埋置至胚胎回收的全过程AMH浓度整体呈下降趋势;2）CIDR埋置当天AMH高浓度组头均回收胚胎数（9.38±1.24）显著高于中等浓度组（6.47±0.56）（P<0.05）,说明CIDR埋置当天AMH浓度高的供体牛超排效果更好,回收胚胎数更多;但是,结果也表明,高浓度组头均未受精卵母细胞数显著高于其他两组（P<0.05）,说明部分卵母细胞未能成功受精,这可能是由于高浓度组牛只更多的卵泡优势化,排卵周期延长导致部分卵母细胞未能完成正常受精;3）人工授精和胚胎回收当天的AMH数据分析结果均表明,3组间各项胚胎生产指标均无显著性差异（P>0.05）;4）通过对供体牛体重记录数据分析发现,不同体重牛只间的体内胚胎生产效率差异也不显著（P>0.05）,但是体况适中组牛只的可用胚胎数、回收胚胎数优于其他两组,尤其是优于体重偏胖组。因此,CIDR埋置时,外周血AMH浓度可以作为青年荷斯坦供体牛筛选标准之一,且供体牛选择时宜选用体况适中的牛只。  相似文献   

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