• Asian-Australasian Journal of Animal Sciences
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• 제32권11호
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• pp.1673-1685
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• 2019

Objective: To evaluate the efficacy of treatments based on gonadotrophin-releasing hormone (GnRH), GnRH-prostaglandin $F2{\alpha}$ ($PGF2{\alpha}$), and/or intense exposure to novel rams to induce fertile estrus without the use of steroid hormones in seasonally anestrous Suffolk ewes. Methods: In the first experiment, ewes were treated with one injection of GnRH, two injections of GnRH administered 7 days apart, or a sequence of GnRH-$PGF2{\alpha}$-GnRH (GPG). In the second experiment anestrous ewes were exposed, for 36 days starting on the day of weaning, to groups of four rams of three different breeds that were alternated every day. Besides exposure to the male effect (ME), the ewes were injected with saline solution (ME group, n = 20), with GnRH (ME-GnRH group, n = 20) or with a sequence of GnRH-$PGF2{\alpha}$-GnRH (ME-GPG group, n = 20). The rams used for male-effect were fitted with aprons to prevent mating, and ewes detected in estrus were bred to selected fertile rams. Ovarian activity was monitored by progesterone determinations in both experiments. Results: In the first experiment sustained induction of ovarian activity was not achieved and no ewe was detected in estrus. In the second experiment induction of sustained ovarian activity was achieved in all groups. Most of the ewes were detected in estrus, 76.7% of the ewes were mated during a 36-d breeding period and 71.7% of all the ewes became pregnant during that period. No significant differences between groups were found for any of these variables. However, estrus detection efficiency was higher in the ME-GnRH group than in the ME group (p<0.05). Conclusion: An intense male-effect, that included the continuous presence and frequent alternation of several rams of different breeds, was sufficient to induce ovarian activity and fertile estrus in Suffolk ewes during the period of deep anestrus without the use of hormones, although addition of GnRH improved the efficiency of estrus detection.

• Korean Journal of Animal Reproduction
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• 제16권3호
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• pp.225-230
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• 1992

Many transgenic mice expressing human growth hormone gene were infertile. To investigate the infertility of these transfenic mice, it was looked into the estrus cycle and sexual behaviour and also tested through in vitro fertilization whether the germ cells of these mice normal or not. The infertile female transgenic mice were mated to the fertile males of ICR strain, but in almost all of them the vaginal plugs were not detected and their estrus cycles by vaginal smear were almost irregular which kept up estrus or diestrus stage. Many male transgenic mice did not have the ability of sexual behaviour. Therefore the viability of germ cells in infertile male transgenic mice was investigated by in vitro fertilization, but the sperm were normally fertilized with the eggs and the transgene of parent was passed on to the progeny. These results consequently suggest that the infertility of transgenic mice experssing human growth hormone gene may be due to the physiological activity of human growth hormone, not germ cells.

• Journal of Embryo Transfer
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• 제25권4호
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• pp.287-290
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• 2010

On January 6, 2010, two months earlier than normal breeding season, a red fox vixen was implanted with synthetic GnRH analogue, Deslorelin. Blood was sampled every 2~3 days from the day of implant to identifying spermatozoa on stains of epithelial cells. Estradiol and progesterone were examined. Even though the vixen was in non-breeding season, she was mated by a male fox. Pregnancy was confirmed by canine pregnancy detection kit that detect relaxin released from placenta. Four healthy pups were born on March 9, 2010. This is the first report showing synthetic GnRH can activate ovarian function and lead to fertile estrus of red fox in non-breeding season.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.595-599
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• 2000

Fine wool sheep (n=18) maintained in a tropical environment were allocated to three treatment groups. Estrus was induced with two injections of $PGF_{2{\alpha}}$ (10 mg. im) at 10 days interval. Superovulation treatment started 2 days prior to the second injection of $PGF_{2{\alpha}}$. Each ewe was treated with a total dose of 25 units FSH (Super-OV) i.m. every 12 hover 3 days; Group 2 were also injected i.m. with 200 IU PMSG at the first injection of FSH; Group 3 was treated as in Group 2 and also with GnRH ($4{\mu}g$ Buserelin) at the onset of estrus. The ewes in estrus were mated with a fertile ram. Ovarian examination and recovery of embryo and ova were performed at laparoscopy and laparotomy on day 3 or 4 after mating. Data for onset of estrus, duration of estrus, number of corpora lutea (CL), number of unnovulated large follicle (LF), embryo recovery rate, embryo quality and fertilization recorded for the 3 groups. Ewes in the Group 1 set in estrus later (p<0.05; $50.0{\pm}7.29h$) than the ewes in Group 2 ($24.5{\pm}3.58$) and 3 ($32.5{\pm}3.58h$). The duration of estrus, ovarian size and ovarian response (number of CL and LF) did not differ significantly (p>0.05) among the 3 groups. The proportion of ewes with a superovulatory response (${\geq}2$ CL) was the lowest (50%) in Group 1 treated with FSH alone but ova/embryo recovery (100%) and fertilization (100%) was significantly (p<0.05) higher than Group 2 (58.3 and 85.7%, respectively) and Group 3 (48.6 and 50%, respectively). It is concluded that in tropical fine wool sheep, there is no difference in the 3 treatments for yield of good quality embryos but ovarian response and ovulation rate increased on additional use of PMSG and GnRH respectively to FSH alone.

• Clinical and Experimental Reproductive Medicine
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• 제47권3호
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• pp.180-185
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• 2020

Objective: Tyrosine phosphorylation is an essential process in many biological systems, including the male reproductive system. The presence of tyrosine-phosphorylated (TyrPho) proteins has been well documented in male reproductive organs, but research in fertile females is still limited. Methods: The ovary, oviduct, and uterus of adult female Sprague-Dawley rats in the estrus phase were used to localize TyrPho proteins using an immunohistochemical technique. These proteins were separated and their expression patterns were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis, respectively. Results: TyrPho proteins were localized in the cytoplasm of the oocyte except the antral fluid; in the granulosa cells, theca cells, and stromal cells of the ovary; at the apical surface of oviductal epithelial cells; and in the basal epithelium and submucosa of the uterine wall. Moreover, we found that 72-, 43-, and 28-kDa TyrPho proteins were localized in the ovary, while 170-, 55-, and 43-kDa proteins were localized in the oviduct. In the uterus, we detected four major bands, corresponding to 61-, 55-, 54-, and 43-kDa TyrPho proteins. Conclusion: Given that these TyrPho proteins were found in major reproductive organs in the estrus phase, these proteins may play important roles in female fertility.

• Korean Journal of Veterinary Research
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• 제29권3호
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• pp.373-381
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• 1989

The aim of the present study was to test the efficiency of estrous induction in the premature, metestrous and anestrous bitches. The estrus was induced with prostaglandin $F_{2{\alpha}}$, estradiol-$17{\beta}$, pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin(HCG) in the treatment A, and with PMSG and HCG in the treatment B. Day 0 was the first day of estrone injection in the treatment A and the day of PMSG injection in the treatment B. Twenty three of the twenty six bitches were laparotomized under general anesthesia between 11 and 18 days after onset of behavioral estrus, whereas three bitches were not laparotomized and remained until parturition. Ovarian responses were evaluated with the total number of corpora lutea or ovulation sites. The uterine horns were flushed with phosphate-buffered saline added heat treated canine serum(10%), the flushing media was collected into watch glass and the ova were examined under stereomicroscope. The results obtained were as follows: 1. Standing estrus was observed on the day $17.7{\pm}1.5$ after injection of estrone in the treament A, but ovarian responses were not detectable. 2. Standing estrus was observed on the day $12.2{\pm}0.2$ after injection of PMSG in the treament Band 14 of 17 bitches showed ovarian responses. Ova were recovered in 9 of the 14 bitches. 3. Ovarian responses were observed in one of the three premature bitches. two of the three metestrous bitches and all of the 11 anestrous bitches. The average number of the ova collected from 9 bitchs were $12.2{\pm}1.4$. 4. Three bitches in the treament B exhibited behavioural estrus and all of them were mated with fertile male dog, resulting the pregnancy in only one bitch. The pregnant bitch gave the birth of two pups.

• Korean Journal of Veterinary Research
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• 제34권4호
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• pp.851-855
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• 1994

The semen from four male dogs which had been proven to be fertile in the past were frozen in a deep freezer at $-60^{\circ}C$ by simple freezing method using methanol and preserved at the same teperature for from 7 to 10 days. The semen were inseminated to 7 female dogs in estrus to find out the usability of this freezing method in artificial insemination for dogs. In addition, post-thaw motility and viability of sperm from two male dogs which had been fertile were also evaluated to investigate individual difference. Successful pregnancy was obtained by artificial insemination with canine semen frozen at $-60^{\circ}C$ by simple freezing method using methanol, namely, 3 bitches among 7 bitches which had been inseminated delivered puppies(42.8%). The average litter size of the whelping dogs were 4.3 puppies. The average post-thaw motility of canine sperm in the cases of conception was showen higher than those of non-conception(65.0% vs. 42.5%), along with the, same result in the average post-thaw viability between the two groups(53.3% vs, 27.5%). Individual difference of post-thaw motility and viability was obtained between two fertile dogs(p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제17권10호
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• pp.1395-1399
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• 2004

The objective of this study was to evaluate the effect of dietary fat inclusion on nutrient intake, body weight, milk production, return to estrus, pregnancy and lambing of winter-lambing, postpartum Awassi ewes. Thirty multiparous, winter-lambing Awassi ewes (body weight=51${\pm}$7.0 kg) were randomly assigned to three dietary treatments (n=10) for 62 days using a completely randomized design. Experimental diets were isonitrogenous, and were formulated to contain 0 (CON), 2.5 (MF), and 5% (HF) added fat, and 33% of the dietary crude protein (CP) as undegradable intake protein (UIP). On day 26 postpartum (day 0=parturition), ewes and their lambs were housed in individual pens for 28 days. Feed offered and refused was recorded daily. At the end of this period, ewes and their lambs within each treatment were combined into one group and fed their respective diet ad libitum. One fertile Awassi ram fitted with a marking harness was allowed with each group for 34 days. No significant (p>0.05) differences in dry matter intake, organic matter intake, and crude protein intake were observed for ewes fed the three experimental diets. No difference was observed in metabolizable energy intake (MEI) for ewes fed the CON and the MF diets (average 8.3 Mcal/d) diet. However, ewes fed the HF diet had greater(p<0.05) MEI compared with the rest of the treatments. Ewe body weights increased throughout the study, unaffected by the experimental diets. No significant differences in milk production were found among ewes fed the three experimental diets. No significant differences were observed in pregnancy rate (6/10, 5/10, 6/10 for CON, MF and HF diets, respectively), lambing rate and the number of lambs per ewe among the three treatments. postpartum reproductive performance of well-fed, winter-lambing Awassi ewes.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.637-642
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• 2005

The objective of this study was to evaluate the effect of dietary undegradable protein (UP) level on body weight change, nutrient intake, milk production and postpartum reproductive performance of Awassi ewes. Twenty-seven multiparous Awassi ewes (initial body weight = 53.3${\pm}$1.6 kg) were randomly assigned to three dietary treatments (9 ewes/treatment) for 62 days using a completely randomized design. Experimental diets were isonitrogenous (15.5% CP), isocaloric, and were formulated to contain 17.9 (LUP), 27.1 (MUP), and 34.0% (HUP) of the dietary CP as UP. On day 10${\pm}$3 (day 0 = parturition) ewes were housed in individual pens for 5 weeks. Feed offered and refused was recorded daily. At the end of this period, animals were removed from their pens and combined into 3 separate groups (LUP, MUP and HUP). One fertile, harnessed ram was allowed with each group for 34 days. Rams were rotated every 2 days among the three groups. Each group was offered the corresponding experimental diet. Organic matter, CP, UP and metabolizable energy intakes were higher (p<0.05) for ewes fed the HUP diet compared with ewes fed the LUP and MUP diets. Ewes fed the HUP diet gained more (p<0.05) weight compared with ewes fed the MUP diet (7.3 vs. 2.1 kg), while ewes fed the LUP diet lost an average of 2.1 kg. Pregnancy rate of ewes fed the HUP diet was 100%, compared with 66 and 33% for ewes fed the MUP and LUP diets, respectively. Lambing rate was greater (p<0.05) for ewes fed HUP (8/9) diet compared with ewes fed the MUP (4/9) and LUP (3/9) diets. These results indicate that Awassi ewes receiving adequate dietary UP level consume more feed and are capable of returning to estrus shortly after parturition and are capable of producing two lamb crops per year.