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1.
OBJECTIVE: To examine the immunogenicity of an equine immunocontraceptive vaccine and its efficacy in controlling hormone-related behaviour. DESIGN: A total of 24 mares at two sites in Australia were vaccinated with an immunocontraceptive vaccine comprising gonadotrophin releasing hormone (GnRH) conjugated to a carrier protein in immunostimulating complex as an adjuvant. Twelve animals at each site received a placebo of adjuvant alone and served as controls for seasonal oestrus, hormonal and behaviour patterns. Animals were observed for injection site reactions, ovarian and follicular activity, and serum levels of antibody, 17beta-oestradiol and progesterone in the weeks following vaccination. Mares were also examined for oestrous behaviour by teasing with a stallion. RESULTS: All mares responded to vaccination. Two weeks following the second vaccination there was a peak in antibody response to GnRH that declined gradually over the following weeks. Commensurate with the elevated anti-GnRH antibody there was a marked effect on ovarian activity with a reduction in 17beta-oestradiol and progesterone levels in the 24 vaccinated mares. There was also a reduction of oestrus-related behaviour as determined by a teaser stallion. This effect lasted a minimum of 3 months and correlated with the initial level of antibody response. CONCLUSION: Following a conventional two-dose immunisation regime this commercially available equine immunocontraceptive vaccine was effective at inhibiting oestrous behaviour for at least 3 months. This vaccine has a high level of safety since there were no significant local reactions nor were there any adverse systemic responses to vaccination.  相似文献   

2.
Objective: To investigate the effect of two dose rates (200 and 400 ng) of a gonadotrophin releasing hormone (GnRH) vaccine on testicular function. Design: A vaccination dose rate experiment. Procedure: Two injections were administered 4 weeks apart to six colts in each treatment group. To maintain immunosuppression until the end of the breeding season, a third injection was given if antibody titres fell below 1000. Results: Effective antibody titres were present for 12 to 27 weeks. Testosterone concentrations decreased from 2.22 to 0.31 nmol/L 6 weeks after primary vaccination. Androstenedione concentrations decreased from 1.78 to 0.28 nmol/L 5 weeks after vaccination. Testosterone and androstenedione concentrations above 0.69 and 0.87 nmol/L were attained 31 to 43 weeks after vaccination. Mean scrotal widths and lengths decreased over 29 weeks from 9.2 cm and 9.7 cm to 6.7 cm and 7.6 cm. At surgical castration these dimensions were 10.1 cm and 11.0 cm. Mean semen characteristics before vaccination and after recovery were: gel-free volume 16.5 and 13.5 mL, sperm concentration 295.5 times 106 315.6 times 106/mL, total sperm per ejaculate 4041 times 106 4657 times 106 live normal spermatozoa 32% and 60%. Histologically, the testes showed active spermatogenesis. The mean testicular parenchyma weights for the 200 and 400 mg groups were 129.0 g and 109.8 g. Daily sperm production per testis and per gram of testis for the 200 and 400 mg groups were 3.7 times 108 2.8 times 106 2.3 times 108 2.0 times 106. Conclusions: Both dose rates suppressed testicular function. Data showed that the vaccine effects were reversible. Individual immune response was less varied in the 200 mg group. Further work is necessary to achieve a less variable response in the immunosuppression of testicular function.  相似文献   

3.
This study aims to characterize the reproductive patterns in Asinina de Miranda jennies during the non‐breeding season. Reproductive activity was surveyed in 12 females, aged between 3 and 18 years old, using ultrasound and teasing with a jack. The animals were monitored from September to April, six in each consecutive year. Of these 12 females, nine showed disruption to the normal pattern of ovarian activity during the non‐breeding season. Loss of normal cyclicity included anoestrus (41.7%), silent ovulatory oestrus (25%), and persistence of corpus luteum (8.3%). Only three females maintained a regular cyclic pattern with oestrous behaviour during the non‐breeding season. Anoestrus began in early November and lasted for an average of 147 ± 28 days (113–191 days), ending near to the spring equinox. Onset of silent oestrous cycles began more erratically, between October and February. In both groups the first behavioural ovulation of the year occurred around the time of the spring equinox. Disrupted reproductive activity was preceded by a shorter oestrous cycle only in females entering anoestrus. The mean follicle size in the first ovulation of the year was larger than in the reproductive season (44.7 ± 2.45 mm vs 39.2 ± 3.60 mm) in anoestrous jennies with protracted oestrus. Though age and body condition score (BCS) were associated, changes in BCS below a threshold of four points (for anoestrus) and five points (for silent oestrus) contributed greatly to disruption of reproductive cycles. BCS in females with regular oestrous cycles during the winter season remained unchanged or exceeded five points prior to the winter solstice.  相似文献   

4.
The aim of this study was to investigate characterization of oestrous response, onset of induced oestrus, oestrous duration, fecundity and fertility in Awassi ewes treatment with intravaginal sponges and Controlled Intravaginal Drug Release (CIDR) devices in combination with pregnant mare serum gonadotropin (PMSG) under local environmental conditions during the non‐breeding season. A total of 62 ewes were divided into three groups. Group CIDR (n = 20) was treated with CIDR devices for 12 days and 400 IU PMSG was injected upon removal of the CIDR. For ewes in Group Sponge (SP) (n = 24), 30 mg fluorogestone acetate was administered to the sheep for 12 days and 400 IU PMSG was injected upon withdrawal of the sponge. Group Control (CON) (n = 18) served as a control group and received no treatment. Adult, intact and sexually experienced Awassi rams were introduced to all groups at the time when the intravaginal devices were removed. There were no significant differences in terms of oestrous response (CIDR: 90%, SP: 87.5%), time to onset of oestrus and duration of induced oestrus between the CIDR and SP groups. The oestrous response of treatment groups was significantly greater (p < 0.05) than in the control ewes. There were no significant differences in pregnancy (CIDR: 70%, SP: 70.8%), lambing (CIDR: 85%, SP: 79.2%) and fecundity rates between ewes treated with CIDR and those treated with sponges. However, pregnancy and lambing rates were significantly (p < 0.05) higher in ewes treated with CIDR or sponges when compared with those in the control group. It was concluded that it is possible to induce fertile oestrus, successful pregnancy and lambing with the treatment of either CIDR or intravaginal sponge in combination with PMSG in Awassi ewes during the non‐breeding season.  相似文献   

5.
Reasons for performing study: Active immunisation against gonadotrophin‐releasing hormone (GnRH) provides a reversible method for control of oestrous behaviour and fertility in mares. Previous reports failed to demonstrate the interval to resumption of cyclic ovarian activity after GnRH‐vaccination. Hypothesis: Administration of the GnRH‐vaccine Improvac in a large group of mares of various ages will result in effective, reliably reversible suppression of ovarian activity within a 2 year period. Methods: The mares, subdivided into 3 age categories, were vaccinated twice (with a 35 day interval) using 400 µg Improvac and monitored via blood samples until Day 720 after initial vaccination for serum progesterone concentration determination by radioimmune assay and anti‐GnRH antibody titre by enzyme immunoassay. Samples were collected until individuals resumed cyclic ovarian activity. Results: All mares showed suppression of cyclic ovarian activity by clinical examination and serum progesterone concentration (SPC) ≤1 nmol/l by Day 70 and 92.2% resumed cyclic activity by SPC at Day 720 with a mean interval = 417.8 days (s.d. ± 23.9; range 232–488 days, median 344 days). A significant age effect (P = 0.028) on the interval, but not on GnRH‐antibody titre response, was observed between the youngest (≤4 years) and oldest (≥11 years) categories. Conclusions: Immunising adult mares of all ages with Improvac resulted in a reversible suppression of cyclic ovarian activity in most mares. An age effect, with the youngest mares showing a longer interval to reversibility, was observed.  相似文献   

6.
Mares are seasonally polyoestrous breeders. Therefore, the first ovulation of the season, following winter anoestrus, is the only cycle in which mares ovulate without the presence of an old CL from the previous cycle. The objective of this study was to compare the length of oestrous behaviour, and plasma progesterone concentrations during the early post-ovulatory period between mares after the first and second ovulation of the breeding season. Overall, 38 mares and 167 oestrous periods were used in the study. From those, 11 mares were used during the first and subsequent oestrous period to measure and compare the post-ovulatory rise in progesterone concentration, whereas all the mares were used to compare the length of the post-ovulatory oestrous behaviour between the first and subsequent cycles of the breeding season. The persistence of the post-ovulatory oestrus was longer (p < .001) following the first ovulation of the year (median of 52 h) compared with the subsequent ovulations (median of 36 h for second and later ovulations groups; n = 38 mares). The progesterone concentration at any of the four 8 h-intervals analysed (28, 36, 76 and 84 h post-ovulation) was lower (p < .01) following the first versus the second ovulation of the year. By 36 h post-ovulation the progesterone concentration of mares at the second ovulation of the year had passed the threshold of 2 ng/ml (2.1 ± 0.33 ng/ml), whereas in the first cycle it was 1.2 ± 0.13 ng/ml. In conclusion, mares had lower progesterone concentrations in their peripheral circulation and longer persistence of oestrous behaviour following the first ovulation of the year compared with the second and subsequent ovulatory periods of the breeding season.  相似文献   

7.
The aim of this study was to determine the level and duration of progesterone secretion during the sequential oestrous cycles in fat-tailed Tuj ewes following tactile and visual separation of rams during the breeding season. For these purposes, rams were separated from the main flock for 50 days starting from the beginning of the breeding season and 21 ewes were randomly selected for the current experiment. In order to assess luteal activity and the length of oestrous cycles, the ewes were blood-sampled thrice or twice weekly for the measurement of progesterone in plasma. The data showed that 3 +/- 0.2 oestrous cycles were observed in this time window, and the first oestrous cycle observed was shorter (P < 0.05) than the following cycles (mean +/- SEM, 14.6 +/- 0.82, 16.5 +/- 0.48 and 17.0 +/- 0.54 days, respectively, for cycles 1, 2 and 3). Progesterone production was significantly lower in the first oestrous cycle compared with the second and third cycles on days 9, 12 and 14 of the cycles. The follicular periods of ewes showed four accumulations (maximum values using a 3-day moving average technique) throughout the study and the percentages of ewes at each accumulation (peak day +/- 1 day) were 50, 35, 65 and 80% for the first, second, third and fourth accumulations, respectively (P < 0.05). It was concluded that progesterone production was lower and the oestrous cycles were shorter during the first oestrous cycle and that tactile and visual separation of rams at the beginning of the breeding season might enhance the synchronizing effect towards the end of the breeding season in the fat-tailed Tuj ewes.  相似文献   

8.
Ovarian tumours in mares represent 2.5% to 6% of the most frequent neoplasms found in the equine species, with a higher chance of benignity. This study aims to describe a case of two different tumours found in the same ovary of a mare that presented clinical signs of suppressed oestrous cycle during 5 years. After unilateral ovariectomy, the ovary was sent to the histopathology examination which determined a mixed tumour of granulosa cell and leiomyosarcoma. After treatment, the mare returned to oestrus and got pregnant in the next season.  相似文献   

9.
Two groups of lactating dairy cows in each of 4 dairy herds were injected with either 0.5 mg (219 cows) or 0.3 mg (118 cows) of Ooprostenol (I.C.I.) The first group of cows were injected from Day 6 to Day 17 of the oestrous cycle (Day 0 — oestrus) and the second group from Day 6 to Day 12. The four herds were selected specifically because oestrus-detection procedures were thorough and reliable. Of the cows receiving the 0.5 mg dose rate, 54.3% were observed in oestrus within 4 days of treatment. The remainder were in groups which were: (i) in oestrus from 5 to 10 days post-treatment (20.5% with prolonged response intervals), and 11 to 20 days post-treatment (15.5% with unaltered cycle lengths); or (ii) experienced a “silent oestrus” in the immediate post-treatment period and either did not show oestrus for a further 3 weeks (6.4% in oestrus from 21 to 29 days post-treatment) or conceived to a single set-time insemination 72 h after treatment (0.9%). Use of the lower dose rate resulted in fewer cows being observed in oestrus within 72 h (43.8% v 31.4%) and a corresponding rise in the percentage experiencing a “silent oestrus” and returning to service (6.4% v 13.6%) or conceiving to set-time insemination (0.9% v 3.4%). Most of the unaltered cycle lengths occurred with cows being treated on Day 6 of the oestrous cycle. The pregnancy rate for the 171 cows observed in oestrus within 4 days of treatment and inseminated at 72 h, or 72h and 96 h, was 57.3%.

Records from this trial, as well as previous trials in which cows were injected with 0.5 mg of Cloprostenol, showed that 446 of 524 cows (85%) injected at from Day 6 to Day 17 of the oestrous cycle were observed in oestrus within 5 days (144 h) of treatment. Amongthese 446 cows, the interval to post-treatment oestrus was influenced by the stage of the cycle at injection. Whereas 89% of the oestrous responses in cows treated on Days 6 to 9 were observed within 72 h of injection, the comparable figures for cows treated on Days 10 to 13 and Days 14 to 17 were 48% and 70% respectively.

Variation in the post-treatment interval to oestrus is greater in lactating dairy cows than in heifers and is not resolved by using double-injection regimes. The reasons for this variation have not been identified. The most effective use of prostaglandins for oestrus synchronisation in lactating dairy cows requires the treatment of groups of animals at similar stages of theiroestrous cycles and their post-treatment insemination at observed oestrus. These requirements may limit the usefulness of this technology in herds with poor breeding management.  相似文献   

10.
Inhalt 39 Färsen und Kühen wurden 2 Tage nach Beendigung einer 18tägigen CAP-Medikation (tägl. 10 mg), d. h. 24 Stunden vor der Besamung, 5 mg Östradiolbenzoat intramuskulär appliziert. 42 zum gleichen Zeitpunkt brunstsynchronisierte Rinder blieben zur Kontrolle ohne zusätzliche Behandlung. Die Tiere mit Östrogenmedikation zeigten eine deutliche Verbesserung der äußeren Brunst (Psyche, Schleimabgang) und der inneren Brunstsymptome (Zervixöffnung, Proliferationsphase des Endometriums, Uteruskontraktion, Follikelreifung). Das Besamungsergebnis lag bei den östradiolbehandelten Tieren nach der Erstbesamung um 2,5 % und nach insgesamt 3 Besamungen um 10 % niedriger als bei den Kontrolltieren ohne Östrogenapplikation. Bei 6 Kühen wurde während der ersten Brunst nach der CAP-Medikation eine Uterusbiopsie vorgenommen. Dabei konnte festgestellt werden, daß sich das Endometrium in einer Sekretionsphase befand. Allerdings waren in einigen Lokalisationen Anzeichen der Proliferationsphase vorhanden. Contents 39 heifers and cows were treated intramuscularly with 5 mg. oestradiol benzoate 2 days after the completion of an 18 day course of CAP medication (10 mg. per day) and 24 hours before insemination. 42 cows at the same stage of the oestrous cycle served as untreated controls. The animals receiving oestrogen therapy showed a significant improvement both in the clinical signs of heat (behaviour and secretion of mucus), and in the internal signs (dilatation of the cervix, proliferative phase of endometrial epithelium, uterine contractions, maturation of the ovarian follicle). The success of insemination in the cows receiving oestrogens was only 2.5% lower than that of the controls after the first insemination and 10% lower after 3 inseminations. An endometrial biopsy was taken from 6 of the cows after the first heat following CAP therapy. This showed that the endometrium was in a secretory phase but in small areas there was evidence of proliferative activity.  相似文献   

11.
This study was carried out to assess the serum profiles of luteinizing hormone (LH), oestradiol, cholesterol and ovarian functions in layer poultry birds (Rhode Island Red: Gallus domesticus) fed a diet containing various concentrations of furazolidone (FZ). A total of 40 birds were randomly assigned to receive FZ 0, 200, 400 or 800 mg/kg feed (ppm) daily during the pre-laying age, i.e. 13-18 weeks (for 5 weeks). Blood samples were collected at weekly intervals. Concentrations of LH and oestradiol in serum were estimated at alternate weeks using radioimmunoassays. Serum cholesterol levels were analysed by an enzymatic calorimetric method. Furazolidone administration was terminated at the 18th week of age. The birds were sacrificed at 22nd week of age and ovarian tissues were processed for morphometric studies. Serum LH, oestradiol and cholesterol levels were affected by age (p < 0.001) and FZ dose (p < 0.001). Serum LH and oestradiol levels were lower (p < 0.05) in birds receiving FZ 800 mg/kg feed daily compared with the controls, whereas serum cholesterol profiles were lower (p < 0.05) in all FZ-administered groups than in the control group. The mean weight of ovaries having no yolky follicles observed in the group receiving FZ 400 or 800 mg/kg feed per day was reduced (p < 0.05) compared with the control group. Dosing FZ at 800 mg/kg feed per day reduced (p < 0.05) the mean volume of ovaries having no yolky follicles compared with the control group. In birds receiving FZ 800 mg/kg feed per day, the mean length of the oviduct was reduced (p < 0.05) as compared with the control group. Morphometric studies revealed that the mean number of oocytes with diameter in the range 401-800 microm decreased (p < 0.05) in birds fed FZ 400 or 800 mg/kg feed per day. Initial egg production was affected by age (p < 0.001) and dose (p < 0.001) of FZ. The mean number of eggs laid by different groups revealed that egg production was reduced (p < 0.05) in birds receiving FZ 800 mg/kg feed per day as compared with the controls. The present data suggest that FZ causes suppression in serum profiles of LH, oestradiol, cholesterol and ovarian functions in Rhode Island Red layer poultry birds. Therefore, great care must be taken with use of FZ in layer poultry birds (Gallius domesticus) with regard to dosage and duration of administration.  相似文献   

12.
An attempt was undertaken to investigate the efficacy of Ovsynch protocol for timed artificial insemination (TAI) with or without Norprolac (antiprolactin) treatment during non‐breeding season (winter months) in yaks (n = 25). During non‐breeding season, plasma prolactin profile has been reported high due to cold and nutritional stress. The Norprolac dose of i.m. administration was standardized for prolactin suppression. Three different doses viz. 2.5, 5.0 and 7.5 mg were attempted and the dose of 7.5 mg Norprolac i.m. per animal was found to be suitable for suppression of prolactin levels up to 30 h. Ovsynch treatment with Norprolac induced more number of oestrous symptoms per animal (4.8 vs 2.1), higher LH peak concentration (24.01 vs 16.16 ng/ml), longer duration of LH surge (6.8 vs 5.2 h) and higher conception rate (70 vs 30%) in Ovsynch plus Norprolac treated animals compared with animals treated with Ovsynch alone. Therefore, this study clearly indicates the opportunity for practical application of the Ovsynch plus Norprolac protocol for TAI in yaks during non‐breeding seasons.  相似文献   

13.
Despite efforts undertaken to conserve the endangered European mink, its reproduction is still poorly studied. The aim was to study its reproductive cyclicity, faecal progesterone concentration and ovarian changes during early pregnancy, with the emphasis on the pre-implantation period and implantation. During the 2004 breeding season, oestrous cycle was monitored in 39 females as well as ovarian changes during early pregnancy in 22 females. During the 2007 breeding season, faecal progesterone concentration measured by radioimmunoassay was monitored during pregnancy in 10 females throughout their pregnancy. The breeding season 2004 started on March 18 and ended on May 10, with the peak recorded in April. The duration of first oestrus was 1–12 days. If not mated, the vast majority of females entered second oestrus after 12–55 days. In general, relatively low faecal progesterone values were detected in European mink; an average of 42.69 ± 4.70 ng/g faeces in oestrous females with a maximum of 176.44 ± 23.01 ng/g faeces on pregnancy day 12. anova indicated a significant effect of the pregnancy stage. Post hoc comparisons with Fisher least significant difference (LSD) test revealed that faecal progesterone concentrations on days 8 and 12 post coitum (p.c.), but not at the end of pregnancy (day 40), were higher when compared with the initial oestrous level. Implantation in this species occurs on day 12 p.c. and was indicated by prominent uterine swellings and failure to flush the uterine horns beyond this day. Advanced luteogenesis was observed with prominent corpora lutea found in ovaries around the time of implantation. To conclude, European mink is a seasonally polyoestrous species; the early pregnancy of European mink resembles that of European polecat, i.e. in both species, implantation occurs on day 12 p.c. without any implantation delay.  相似文献   

14.
Calves vaccinated with Anaplasma centrale were treated with 20 mg/kg of long-acting oxytetracycline (OTC/LA) before or simultaneously with vaccination or up to seven months later. Of 40 animals given one or two of OTC/LA from 3 to 13 days before vaccination, 23 become patent after vaccination, with an average prepatent period almost twice as long as that in non-treated vaccinated controls. Upon challenge with 2 x 10(8) A. centrale per dose all 17 previously non-patent calves showed average maximum parasitemias of 2 to 3.8%. Out of 30 calves treated with two to four doses of OTC/LA from one to four weeks after vaccination, 29 remained negative for A. centrale and reacted to challenge infection with average maximum parasitemias of 6.9-7.8%. Five out of 10 calves receiving OTC/LA simultaneously with the vaccination, and all of a separate group of 10 calves treated with a single dose seven days after vaccination, become patent an average of 51.6 and 63.5 d, respectively, after vaccination. Upon challenge, the five previously non-patent calves showed an average of 5.2% maximum parasitemia. In all groups, only rare parasites were seen in previously patent calves after challenge. Thirty calves treated with 2-4 doses of OTC/LA about six months after vaccination showed no or only a few parasites upon challenge. The above results show that treatment with single or multiple doses of OTC/LA a few weeks before or after administration of live A. centrale vaccine can interfere with elaboration of immunity.  相似文献   

15.
49 anoestrous ewes (German Blackface) were treated with 0,1 mg oestradiolvalerianate (OT) during 3 successive days. Intensive follicular development could be observed 24–48 brs. later and 6.5, % of the animals ovulated. HCG (500–700 IU) did not improve the effect on ovulations. Better results were obtained near the end of the anoestrous season. In spite of distinct heat symptoms sexual behaviour was not intact, most of the treated ewes refused the ram. From 84 anoestrous ewes treated by the same method during April, May und July ca. 80 % accepted the ram, 40 % lambed, 20 % conceived during the first heat, 10 % during the second oestrous, 10 % 4–9 weeks after treatment. Only 20 % of the 48 control animals lambed. In maiden-ewes, 6–7 months of age, ovulations without heat could be stimulated by psychological factors (mounting by rams, driving, transport etc.) within 24 hrs. During August 66 % of the immature animals ovulated after treatment with 3 × 0,05 mg OV, but refused the ram. During October all immature animals ovulated following a single injection of 0,05 mg OV and all were mated. The fertilization rate of the eggs was low.  相似文献   

16.
In Exp. 1, 45 fine-wool ewes received (sc) either 0, 50 or 100 mg epostane (3-beta-hydroxysteroid dehydrogenase inhibitor) to examine effects on return to estrus and conception rates. Treatments were imposed on d 10 of an estrous cycle (estrus = d 0) and jugular blood samples were collected once daily on d 8 and 9, twice daily on d 10 through 13 and once daily from d 14 until first post-treatment estrus or d 20 (15 ewes/treatment). Intensive samples were obtained hourly for 6 h after treatment (d 10; five ewes/treatment). Serum progesterone (P4) before treatment was similar among groups; but by 2 h after treatment, epostane-treated ewes had lower (P less than .10) values than controls. By 6 h post-treatment, serum P4 in ewes receiving 50 (1.0 ng/ml) and 100 (.9 ng/ml) mg epostane was well below control values (3.2 ng/ml). By 7 d after treatment, 93.3% of ewes treated with 50 mg epostane had recycled compared with 66.7 and 33.3% of those receiving 100 and 0 mg, respectively (P less than .10). Similarly, 93.3, 53.3 and 26.7% of ewes receiving 50, 100 or 0 mg epostane, respectively, lambed to breeding within 7 d of treatment (P less than .05). Overall conception rates during a 34-d breeding season were similar among groups. Preweaning performance of offspring did not differ among maternal treatments.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

17.
This study aimed to elucidate the effects of repeated pregnant mare serum gonadotropin (PMSG) treatment for oestrous synchronization (ES) on ovarian gene expression and reproductive parameters in Xinong Saanen dairy goats, the dominant breed of dairy goat in China. The experiment was carried out at the Research Station of Northwest A&F University (NWAFU), China (34°16′N, 108°4′E). Forty‐one does were randomly assigned to groups receiving ES treatments thrice every fortnight (3‐PMSG group; n = 19), or ES treatment only once simultaneously with the third ES treatment in the 3‐PMSG group (1‐PMSG group; n = 22) during middle of the breeding season from late July (14 hr light) until late September (12 hr light). ES treatment was performed via intravaginal insertion of a controlled internal drug release (CIDR) device impregnated with 300 mg progesterone (P4), followed by 300 IU PMSG injections 48 hr before CIDR withdrawal. Oestrus was monitored using vasectomized bucks. Ovaries of three goats in oestrus from both groups were harvested for morphological examination and RNA sequencing (RNA‐Seq). Then, all the oestrous goats in the 1‐PMSG (n = 21) and 3‐PMSG (n = 11) groups were artificially inseminated twice. The 3‐PMSG group showed reduced oestrous rate (57.89%), pregnancy rate (31.58%) and litter size (1.17) compared, respectively, with 95.45%, 68.18% and 1.67 for 1‐PMSG group (p < 0.05). However, no differences were found in the ovarian morphology between the 1‐PMSG and 3‐PMSG groups (p > 0.05). RNA‐Seq revealed 114 differentially expressed genes (DEGs) in the ovaries of the 3‐PMSG group, among which GCG, FSTL3, TET3 and AQP3 were deemed novel and promising candidate genes for regulating fertility. The present study indicates that the three‐time PMSG treatment dysregulated several ovarian genes, thereby reducing reproductive performance.  相似文献   

18.
The study was aimed to assess the influence that short‐term progesterone treatments have on follicular dynamics, oestrus and ovulation in sheep. The treatment was tested thereafter in a field trial to assess its fertility after AI with fresh semen. In a first experiment, 12 ewes without CL were grouped to receive a new (n = 6) or used CIDR (n = 6) for 7 days and blood samples were obtained to follow plasma progesterone profiles. In a second experiment, 39 cycling ewes were synchronized by a 7‐day P4+PGF2α protocol using a new (n = 20) or a 7‐day used CIDR (n = 19). Half of both groups received 400 IU eCG and half remained untreated as controls. Ultrasound ovarian examination and oestrous detection were used to compare follicular dynamics, oestrus and ovulation in both groups. In a third experiment, 288 ewes in 3 farms were synchronized by the short‐term P4+PGF2α+eCG protocol and ewes were AI with fresh semen 24 h after oestrous detection. Lambing performance was used to test the fertility of the treatment. In Experiment 1, ewes with new inserts presented higher P4 concentration than ewes with used inserts throughout the sampling period (p < 0.05) and exhibited a P4 peak at days 1‐2 of the treatment that was not observed in ewes with used inserts. In Experiment 2, ewes treated with new and used inserts show similar ovarian and behavioral traits (p > 0.10). However, ewes treated with eCG show shorter interval to oestrus (p = 0.004) and tend to have larger mature CL (p = 0.06). In Experiment 3, oestrous presentation and lambing performance after AI with fresh semen was considered normal compared to published results. Results suggest that the oestrous synchronization protocol based on P4+PGF2α allows little control of follicular dynamics without compromising fertility after AI with fresh semen provided that eCG is added at the end of the treatment.  相似文献   

19.
The agglutinin response of four groups of goats inoculated with Brucella melitensis vaccine 0, 1, 2 and 4 weeks following experimental infection with Trypanosoma congolense was compared with that in non-infected controls. Four weeks after vaccination the goats were treated with a trypanocidal drug and the recovery of the immune response observed. The results indicated that the majority of animals had a significantly but not completely suppressed antibody response. This was most marked in the group vaccinated 2 weeks post-infection, which corresponded with the onset of parasitaemia. Although the mortality rate in the infected goats was high the titre in those remaining animals that were treated with the trypanocidal drug increased immediately after treatment. The possible implications of trypanosome induced immunosuppression for vaccination programmes in goats are discussed briefly.  相似文献   

20.
To determine seasonal changes in circulating leptin concentrations, as well as leptin fluctuations in various patterns of seasonal ovarian activity, blood samples were taken in 107 Lipizzan fillies aged 1–4 years over the whole year from January to December. Serum concentrations were measured in samples obtained once a month (leptin) or twice a month (progesterone), and evaluated with respect to the age of animals (yearlings, 2-, 3- and 4-year olds) and the pattern of ovarian activity (anoestrous, seasonal cycle, prolonged cyclicity, continuous cyclicity). The mean and monthly leptin concentrations in 3- and 4-year olds were significantly higher than in yearlings and 2-year olds (p < 0.001). Circulating leptin levels in 3- and 4-year olds increased significantly in summer, to peak in August and then decline significantly (p < 0.001) in autumn. The fluctuations in younger fillies were less evident. The highest mean serum leptin concentrations were observed in fillies exhibiting continuous cyclicity and the lowest in those, exhibiting seasonal cyclicity (p < 0.001). In anoestrous fillies, leptin concentrations were lower than in fillies with prolonged or continuous cyclicity but higher than in fillies with seasonal cyclic activity (p > 0.05).  相似文献   

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