• Asian-Australasian Journal of Animal Sciences
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• 제13권4호
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• pp.440-445
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• 2000

Thirty lactating Javanese thin-tail ewes (12 ewes had been injected, prior to mating, with 700 IU pregnant mare serum gonadotropin, and 18 ewes with saline as a control) were used to evaluate the effect of superovulation on milk production during lactation and mammary chemical indices at the end of lactation. Thirteen ewes (9 control and 4 superovulated ewes) were fed at low and the other 17 ewes (9 control and 8 superovulated ewes) were fed at high quality ration. Superovulated ewes, either fed at low or high quality ration, had dramatically higher milk yields (57%). At the end of lactation, superovulated ewes had higher mammary dry fat-free tissue, mammary DNA concentration, total mammary DNA and RNA contents than nonsuperovulated ewes. Superovulation did not affect mammary RNA and collagen concentrations, and total collagen content. Ration quality did not significantly increase milk production during lactation and mammary chemical indices at the end of lactation. The observed increase in milk production in the superovulated ewes was probably due to the increased mammary secretory cell number and their synthetic activities during lactation as a result of the increased endogenous hormonal stimulation of mammary growth and development during pregnancy.

• Asian-Australasian Journal of Animal Sciences
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• 제24권10호
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• pp.1365-1371
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• 2011

The intensity and duration of sexual behavior in Bos indicus was assessed through the continuous observation of sexual receptivity. Two groups of cows were formed: only synchronized (n = 50) and other group further superovulated (n = 20). An intravaginal implant that released progesterone over 9 d was used. After removing the implant, 25 mg of $PGF_{2{\alpha}}$ was administered. In the superovulated group, the administration of 280 mg (Follicle stimulant hormone) FSH-P1 per cow with a decreasing dosage over 4 d was utilized. In both groups, behavioral observations began at the moment of implant removal. Sexual behavior was analyzed using a Kruskal-Wallis test to compare the mean of hours in estrus, effective mountings and number of mounts/hour during estrus. A nonparametric survival analysis was performed using the time in two ways: i) when an event happened it was placed in a 24 h timeframe and, ii) the time of observation in continuous form (96 h) assessing the difference between curves by the log rank test Chi-square. The only significant difference was the number of mounts/h during receptivity (p<0.05). In the superovulated group three periods of sexual activity during the day were identified, with these events being of greater frequency and duration than the synchronized group (p = 0.02); besides, the superovulated group began estrus before the synchronized group (p = 0.0035) when using the total period. In a simulation study, when the number of observations went from two (06:00-18:00) to three periods (06:00, 12:00 and 18:00) cows detected accurately (<6 h after the onset) increased more than 20%. The results show that superovulated cows presented greater intensity and duration of sexual activity in contrast with only synchronized animals.

• 한국수정란이식학회지
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• 제9권2호
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• pp.167-172
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• 1994

This experiment was arried out to investigate the development of ea4y rabbit embryos in vivo. Twenty-six New Zealand White does were superovulated by treatment with PMSG(Intervet Co; I. M single injection, 150. U./rabbit) followed 3 day later by simultaneous I.V injection of 100 I.U HCG (Intervet Co, )and natural service with fertile male. All of does was killed at the specific times (24, 27, 30, 36, 42, 50 and 93 h post-hCG) to find out the early embryonic development in vivo respectively. Embryos at the specified stages of development were obtained at the following times after injection of hCG; one-ceH at 24 h, two-cell at 24~27h, four-cell at 27~36 h, morulae at 50 h and early blasto-cyst at 93 h and expanded or hatching blastocyst at 144 h. Number of embryos recovered per rabbit superovulated was 26.1 and average of recovery rate was 83.7%. The results suggest that superovulation was efficient for the increase of embryo number in rabbits, and as shown in results, asynchronous cleavage was prevalent among the recovered embryos.

• 한국가축번식학회지
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• 제21권4호
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• pp.363-371
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• 1997

The present study was carried out to investigate the effect of gonadotropin administration on blood ovarian steroid hormone in angora rabbit. Mature angora rabbits were primed for superovulation with PMSG 100IU. Eighty hours later, the rabbit were induced to ovulate with HCG 100IU. In exp 1, blood progesterone and estradiol of superovulated does were measured by radiommunoassay. Blood progesterone concentration at 93, 99, 102 and 114 hours after HCG injection were 12.9$\pm$0.5, 34.8$\pm$5.1, 12.2$\pm$2.7 and 43.4$\pm$5.8ng/ml, respectively. Mean progesterone concentration of blood collected at 99 and 114 hours after HCG injection(p<0.05). However, mean blood estradiol concentration was not changed. In exp 2, superovulated does were unilaterally ovariectomized at 96 hours after HCG injection. Blood progesterone concentration was tend to be decreased after ovariectomy. Nosignificant changes in blood estradiol concentration was observed after ovariectomy. In exp 3, superovulated does were bilaterally ovariectomized at 96 hours after HCG injection Ovariectomized does were treated with progesterone. Blood progesterone level in the rabbits treated, twice daily, with 5mg progesterone after ovariectomy was similiar to that in the superovulated intact rabbits. Blood estradiol concentration of the rabbits after bilateral ovariectomy was beyond detection range. Blood progesterone concentration was significantly decreased to 7.6$\pm$3.0ng/ml wi thin 3 hours after ovriectomy(p<0.05). However, that value was increased to 34.8$\pm$8.2ng/ml by 5 mg progesterone treatment and this elevated level was significatnly decreased to 7.3$\pm$2.4ng/ml at 12 hours after progesterone administration(p<0.05).

• 한국가축번식학회지
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• 제13권1호
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• pp.26-31
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• 1989

This study was carried out to investigate the effects of PMSG and/or HCG treatment on superovulation and fertilization in the golden hamster. The results obtained were summarized as follows: 1. The female groups treated with 30 IU PMSG or 30 IU PMSG＋25IU HCG ovulated more eggs than those treated with 15 IU PMSG or 15 IU PMSG＋25IU HCG(P<.01). All the PMSG treatment groups superovulated as compared with the untreated control group(P<.01). There were no differences on fertilization rate between the superovulated groups and the control group. 2. The fertilized ova were obtained only by the female group treated with 30 IU PMSG at 1000hr on day 1(morning of ovulation) of the estrous cycle. 3. The intervals between PMSG and HCG injection necessary to obtain the consistent superovulation and fertilized ova were 66hr and 72hr. 4. The superovulated ova were collected from oviduct 48hr, oviduct and uterus 72hr, and uterus 96 hr after mating. 80.3% of two cell, 75.8% of eight cell, and 73.7% of blastocyst of the ovulated ova occurred 48hr, 72hr, and 96hr after mating, respectively.

• 대한수의학회지
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• 제39권2호
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• pp.276-286
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• 1999

In the present study, to understand how gonadotropin-releasing hormone (GnRH) affects ovarian functions in superovulated rats, we examined the effects of GnRH agonist on the ovulatory response, the morphological normality and nuclear maturation of ovulated oocytes, the ovarian weight, the ovarian histology, and the circulating steroid hormone ($17{\beta}$-estradiol, progesterone and testosterone) levels in immature rats pretreated with 30IU pregnant mare serum gonadotropin (PMSG) and supplemented with 10IU human chorionic gonadotropin(hCG). GnRH agonist was intravenously injected via jugular vein catheter every 20min for 4hrs in early follicular phase (from 6hr after PMSG) of superovulated rats. In addition, GnRH antagonist, Antide, was intravenously injected in combination with GnRH agonist to verify the effects of GnRH agonist on ovarian functions. All animals were sacrificed at 72hr after PMSG administration. The administration with GnRH agonist in early follicular phase of superovulated rats caused inhibition of ovulatory response, increased the proportion of abnormal appearing oocytes(especially, in the rats of the group treated with 500ng GnRH agonist), decreased ovarian weight and promote follicular atresia, compared to those from the rats of control regimen that were not treated with GnRH agonist. In addition, the treatment with GnRH agonist in the superovulated rat distinctly decreased serum steroid hormone ($17{\beta}$-estradiol, progesterone and testosterone) levels in preovulatory phase. On the other hand, the inhibitory effects of GnRH agonist treatment in superovulation-pretreated rats on ovarian functions were totally reversed by the combination with GnRH antagonist, Antide. The nuclear maturation of oocytes recovered from the oviducts in immature rats treated with GnRH agonist and/or GnRH antagonist was characterized by prematurity and asynchronization in early follicular phase, which was similar to control group. The overall results of this study indicate that GnRH agonist disturbs directly ovarian function in early follicular phase of superovulated immature rats in terms of ovulatory response and morphological normality of ovulated oocytes. This concept has been further evidenced by the findings of a great decrease in ovarian weight, a marked increase in follicular and a distinct decrease circulating steroid hormone ($17{\beta}$-estradiol, progesterone and testosterone) levels in GnRH agonist treatment regimen in early follicular phase.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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• pp.14-14
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• 2002

The purpose of this study was to determine the effect of bST treatment on progesteron concentration, embryo recovery and pregnancy rate following embryo transfer. Donor cows were superovulated with Folltropin-V and PGF₂ α combination method and then inseminated with frozen semen 3 times 12 hrs interval. Donor and recipient cows were assigned to control and bST group, of which was given a single injection of bST (500 ㎎, sc) at insemination or estrus detection. Embryo collection of superovulated cows were flushed nonsurgical method at 7 to 8 days after artificial insemination. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• 제20권9호
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• pp.1354-1360
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• 2007

The aim of this study was to evaluate if oocytes, aspirated from postovulatory ovarian follicles of superovulated rabbits 14 h post-hCG administration, could be efficiently used as ooplasm recipients for somatic cell nuclear transfer (SCNT). Within a common SCNT protocol, a comparison between oocytes recovered by direct aspiration (aspirated) from available ovarian follicles and oocytes flushed out from oviducts (flushed) was carried out. The results showed that maturation and enucleation rates of aspirated oocytes were 70.7% and 69.2%, significantly lower than 95.3% (p<0.01) and 83.6% (p<0.05), respectively, from flushed oocytes. However, following enucleation of matured oocytes as ooplasm recipients for SCNT, no difference was recorded in fusion and cleavage rates, as well as blastocyst development from cleaved embryos or hatching of blastocysts between aspirated and flushed groups. Additionally, some matured aspirated and flushed oocytes were also used for immediate parthenogenetic activation and the resulting embryo development was not significantly different. Results from this study show the following: i) the majority of oocytes aspirated from postovulatory ovarian follicles of superovulated rabbits 14 h post-hCG administration are matured and can be used directly as ooplasm recipients for SCNT; ii) the reconstructed embryos derived from these oocytes have similar in vitro developmental ability to those flushed from the oviducts.

• 한국수정란이식학회지
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• 제3권1호
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• pp.24-30
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• 1988

This study was conducted to investigate the effect of unilateral ovariectomy on the embryo survival and changes of plasma progesterone and estradiol concentration. Mature Angora rabbits were divided into 2 groups (Superovulation and unilateral ovariectomy after superovulation). Unilateral ovariectomied rabilts were subdivided into two groups according to the time of ovariectomy (24 hours and 96 hours after mating). The results obtained were summarized as follows; 1. After unilateral ovariectomy, survival rate and collecting rate of embryos recovered from contralateral and ipsilateral oviduct and uterus were not different, and were lower than intact rabbits. 2. Plasma progesterone concentration at 93, 99, 102 and 114 hours after HCG injection in superovulated rabbits were 12.9 $\pm$ 0.5, 34.8 $\pm$ 5.1, 12.2 $\pm$ 2.7 and 43.4 $\pm$ 5.8ng/ml, respectively. Mean progesterone concentrations were significantly higher at 99 and 114 hours than at 93 and 102 hours (p <0.05). But plasma estradiol concentration was not different. 3. Plasma progesterone concentration in unilateral ovariectomized rabbits was somewhat decreased after unilateral ovariectomy. Plasma estradiol concentration was not different.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.854-861
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• 1999

Seventeen pregnant ewes (8 superovulated and 9 non-superovulated) were used to study correlations of maternal serum progesterone concentrations with uterine and fatal weights at weeks 7 and 15 of pregnancy. Statistical analyses indicated that uterine growth during the first 7 weeks of pregnancy highly associated with maternal serum progesterone concentration (r=0.87 and 0.85, with wet and dry uterine weights, respectively). Ewes with higher maternal serum progesterone concentrations had higher total and average fetal weights at week 7 of pregnancy (r=0.89 and 0.86, respectively). At week 7 of pregnancy, wet and dry uterine weights highly correlated (p<0.01) with total and average fatal weights (r=0.99 and 0.80, 0.98 and 0.75, respectively). Maternal serum progesterone concentrations, however, did not correlate (p>0.05) with wet and dry uterine weights (r=0.36 and 0.47, respectively) and with total and average fetal weights (r=0.20 and 0.58, respectively) at week 15 of pregnancy. However, wet and dry uterine weights had high correlation with total fetal weight (r=0.97 and 0.95, respectively), without significant correlation with average fetal weight. It was concluded that during the embryonic stage of pregnancy, the levels of maternal progesterone were highly correlated with uterine and fetal growths, while during the fetal stage pregnancy, the correlation became less evident.