Endocrine responses induced in anestrous goats by the administration of different hormones after a fluorogestone acetate treatment (original) (raw)
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Endocrine responses of goats after induction of superovulation with PMSG and FSH
Reproduction, 1983
Goats in Group A were pretreated for 9 days with a synthetic progestagen, administered via intravaginal sponge, and 1000 i.u. PMSG s.c. on Day 12 of the oestrous cycle. Goats in Group B had the same PMSG treatment, but not the progestagen pretreatment. Group C goats received a s.c. twice daily injection of a porcine FSH preparation (8 mg on Day 12, 4 mg Day 13, 2 mg Day 14 and 1 mg Day 15). Oestrus was synchronized in all animals by 50 \ g=m\ gcloprostenol, 2 days after the start of gonadotrophin treatment. The vaginal progestagen sponges were removed from Group A at the same time. Mean ovulation rate was slightly higher in FSH-treated than in the PMSG-treated animals, whereas the incidence of large follicles that failed to ovulate was significantly elevated in PMSG-treated animals in Group B. More goats in Groups A and B than in Group C exhibited premature luteal failure. Progestagen pretreatment appeared to suppress both follicular and luteal activity, as indicated by numbers of large non-ovulating follicles and by the magnitude and duration of elevated plasma oestradiol levels following PMSG stimulation, and by decreased plasma progesterone levels before and after PMSG treatment. Oestrogenic response to FSH was considerably less than that to PMSG, as indicated both by a considerably shorter duration of elevation of circulating oestradiol levels during the peri-ovulatory period, and by lower maximal oestradiol levels. Differences in the ovarian responses to PMSG and FSH may be attributed primarily to differences in the biological half-life of each preparation.
Serum LH peak and ovulation following synchronized estrus in goats
Small Ruminant Research, 2007
This study was aimed at comparing the temporal relationship between estrus, the LH peak and ovulation following estrous synchronization in goats using medroxiprogesterone acetate (MGA) or fluorogestone acetate (FGA). Twenty-four cyclic goats were randomly assigned to two treatments: MGA group (n = 12) that individually received a daily oral dose of 0.22 mg MGA for 12 days, and a FGA group (n = 12) treated for 12 days with intravaginal sponges containing 45 mg FGA. The goats from both groups were treated with a prostaglandin analogue (75 μg Cloprostenol i.m.) during the last day of their progesterone treatment. Estrous detection was carried out every 4 h after the end of the treatment, and blood samples for the determination of the serum LH concentrations collected at 2 h intervals for 24 h from the onset of estrus. Ovulation was detected with the aid of transrectal ultrasonography, performed every 4 h starting 15 h after the onset of estrus. All goats showed estrus. In the MGA group the onset of estrus occurred later and was more variable in relation to the end of treatment (86.7 ± 3.9 h), compared to the FGA group (44.4 ± 1.5 h; P < 0.01). The interval between the LH peak and ovulation was significantly (P < 0.05) longer in the MGA group (26.2 ± 1.1 h) than the FGA group (22.4 ± 0.8 h). There were no differences regarding the intervals from the onset of estrus to the LH peak (14.9 ± 1.8 and 15.3 ± 0.9 h) and to ovulation (40.1 ± 2.3 and 37.6 ± 0.5 h) for the MGA and FGA groups, respectively. The amplitude of the LH peak was not different between groups. It could be concluded that the timing of the LH peak and ovulation is not related to the end of treatment, but with the time of onset of estrus. The longer and more variable interval for estrous demonstration following MGA treatment, represents a serious limitation for its use in synchronization programs in goats, where mating is to be performed on a fixed-time basis.
Ovarian responses of anoestrous goats to stimulation with pregnant mare serum gonadotrophin
Animal Reproduction Science, 1982
Armstrong, D.T., Pfitzner, A.P., Porter, K.J., Warnes, G.M., Janson, P.O. and Seamark, R.F., 1982. Ovarian responses of anoestrous goats to stimulation with pregnant mare serum gonadotrophin. Anim. Reprod. Sci., 5: 15--23.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2013
The objective of this study was to evaluate the efficiency of two doses of PGF associated or not to hCG on the associated reproductive parameters in dairy goats. A total of 29 goats received two doses of 30µg d-cloprostenol latero-vulvar at a 10 day intervals (Day 1 and Day 10). The does were allocated according to body weight and body condition score into two treatments, to receive hCG (250IU) or saline at estrus onset. After the second dose of PGF, estrus was monitored and ultrasound exams were performed twice daily. All does were inseminated 16h after estrus onset. Blood collection was performed every day for progesterone assay. The use of hCG at estrus onset did not affect any studied parameter and therefore the data were pooled. Estrous response rate was similar (P>0.05) after the first (75.9%, 22/29) and the second dose of PGF (79.3%, 23/29). The interval between the administration of PGF and estrus onset was greater (P<0.05) after Day 1 (75.8±53.9h) than Day 10 (47.7±10...
Animal Reproduction Science, 2007
The effect of the so-called Short-Term Protocol (5-day progesterone treatment + PGF 2 ␣) on ovarian activity and LH surge was studied in goats. The goats received 250 IU eCG at the time of device withdrawal (eCG group; n = 7), or 200 g of EB (estradiol benzoate) 24 h after device withdrawal (EB group; n = 8), or received neither eCG nor EB (control group; n = 8). The Short-Term Protocol induced greater (4.1 ± 1.1 ng/ml) progesterone serum concentrations at 24 h after start of the treatment, that declined to 0.2 ± 0.1 ng/ml at 12 h after device withdrawal. In all of the groups, the maximum concentration of estradiol-17 was reached at about 36 h after device withdrawal. Maximum concentration was greater in the EB group (76.9 ± 24.6 pmol/l) than in the control group (41.8 ± 9.0 pmol/l; P < 0.01), with the eCG group showing intermediate concentration (70.3 ± 32.5 pmol/l; P = NS). The LH peak occurred earlier in the eCG group (38.4 ± 2.0 h after device withdrawal) and in the EB group (41.0 ± 4.1 h), than in the control group (46.3 ± 5.1 h; P < 0.05). Ovulation occurred earlier in the eCG group (5/7) and in the EB group (8/8) (58.8 ± 2.7 h and 63.0 ± 5.6 h, respectively), than in the control group (7/8) (70.2 ± 8.3 h; P < 0.05). In summary, the Short-Term Protocol induced similar concentrations of progesterone among treated goats. In addition, eCG or EB resulted in a similar increase in estradiol-17 and a similar LH surge, which induced ovulation in most females (86.7%) in a consistent interval (about 60 h) after the end of progesterone exposure.
Slovenian veterinary research, 2024
This study aimed to compare the effects of a single dose of GnRH or hCG administered at the beginning of the short-term oestrus synchronization protocol on ≥4 mm diameter follicles in Saanen goats during the breeding season. The goats estrus cycles were synchronized with intravaginal sponges containing 60 mg of medroxyprogesterone acetate for five days. Additionally, 1 ml of physiological saline solution (control-group; n=30), 0.004 mg of buserelin acetate (GnRH-group; n=31) or 150 IU of hCG (hCG-group; n=31) were injected intramuscularly to the goats during the sponges insertion. Transrectal ultrasonographic examination was performed immediately before and 24 h after intravaginal sponge application into all goats and follicles with a diameter of ≥4 mm in the ovaries were counted. Blood samples were collected on the same days to determine serum progesterone (P4) and estradiol (E2) concentrations. At the first ultrasonographic examination, the percentages of ≥4 mm diameter follicles were 56.66% (17/30), 54.83% (17/31) and 70.96% (22/31) in the control, GnRH and hCG groups, respectively. The percentage of goats with reduced follicle diameters 24 h later was 29.41% (5/17), 52.94 (9/17) and 59.09% (13/22) in the same groups, respectively. The mean regression rates of follicle diameters between days 0 and 1 in each group were significantly different (P<0.05). Serum E2 concentrations were significantly different (P<0.05) between days 0 and 1 in hCG group. There were no differences in serum E2, P4 concentrations and mean regression rates in follicle diameters between days 0 and 1 for all groups. As a result, a significant relationship between the administration of hCG or GnRH and the reduction of large follicle diameters could not be established.
Animals
Sexual activity in domestic goats is positively influenced by reducing the photoperiod. Various protocols have therefore been developed in goats for the induction and synchronization of estrus during those months in which their sexual activity is reduced. The present observational study evaluates the periovulatory hormonal profile in Payoya goats (n = 24), during a non-favorable photoperiod (i.e., spring), being treated for estrus induction. The treatment comprised the vaginal insertion of sponges impregnated with progestogen (fluorogestone acetate, FGA), together with cloprostenol and equine chorionic gonadotrophin (eCG), 48 h before the end of the treatment. When the treatment ended, the plasma concentrations of the LH, FSH, progesterone and estradiol were determined. The goats were inseminated 46 h after the sponge withdrawal, and a pregnancy diagnosis was carried out 40–45 days after the insemination. Various parameters were monitored, such as the peaks of luteinizing hormone (L...
The effects of different PMSG doses on estrus behavior and pregnancy rate in Angora goats
animal, 2018
Artificial insemination protocols depend on efficient behavioral estrus detection and insemination time in Angora goat. Therefore, we aim to determine the accuracy of an estrus scoring system in Angora goats with different PMSG doses during the breeding season. Does (n: 260) were randomly divided into three groups: group-1 (n: 93), group-2 (n: 85) and group-3 (n: 82). All animals received an intravaginal sponge on day 0 for 11 days, and on the day of sponge insertion 150 μg prostaglandin F2Α was administered. Pregnant mare’s serum gonadotropin was injected 300, 400 and 500 IU intramuscularly 24 h before sponge removal to groups 1, 2 and 3, respectively. Estrus signs were detected with a teaser buck, 24 h after sponge removal according to a visual scoring system. Artificial insemination was performed with 0.25 ml fresh diluted semen at 43 to 45 h after sponge removal. Differences were observed within PMSG groups in terms of standing, tail wagging, courtship behavior, vaginal discharg...