Average Number Of Corpora Lutea Research Articles

Impact of Arsenic on Mouse Ovaries Over Three Generations

Abstract This study aimed to measure the total arsenic content deposited in the ovaries of three consecutive generations of mice. The animals were treated with two different concentrations to determine whether histological changes were caused in the ovaries. The control group of mice received tap water, whereas the experimental groups were given different concentrations of dissolved arsenic (III)-oxide. The arsenic content in the ovaries in both experimental groups increased with each generation. The highest content was recorded in the third generation of the second experimental group. Between the two experimental groups in each generation, significant differences in the average number of corpora lutea and ovarian follicles were identified. Arsenic caused structural changes in the ovaries in both experimental groups in all three consecutive generations.

Influence of superovulation on the production of native Vietnamese pig embryos in vivo and embryonic survival after vitrified-thawed

We aimed to evaluate the influence of superovulation on the production of native Vietnamese pig embryos in vivo and embryonic survival after vitrified-thawed. The average number of follicles, corpora lutea, and recovered embryos of the superovulation group was higher than non-superovulation group (13.56 vs. 7.45, 12.32 vs. 6.12, and 10.91 vs. 5.67; P < 0.05, respectively). The average number of follicles of 4th repeated superovulation was lower than the first, second, and third repeated superovulation (10.57 vs. 13.56, 12.91, and 12.32, P < 0.05, respectively). The average number of corpora lutea and recovered embryos of 4th and third repeated superovulation was lower than first and second superovulation (9.57 and 7.58 vs. 12.32 and 11.84, 10.91 and 9.28 vs. 6.86 and 5.42, P < 0.05, respectively). The average number of follicles of the Co Binh Thuan pig was higher compared to Muong Te pig (16.78 vs. 14.58, P > 0.05, respectively) and Kieng Sat pig (16.78 vs. 13.56, P < 0.05, respectively). The average number of corpora lutea and recovered embryos of the Co Binh Thuan pig was higher than Muong Te pig and Kieng Sat pig (16.14 vs. 12.36, and 12.32, 14.34 vs. 10.98 and 10.91, P < 0.05, respectively). There was no difference in survival and hatching blastocyst rates of native Vietnamese pig embryos in vivo after thawing between breeds (P > 0.05). When vitrified-thawed pig embryos in vivo were transferred, 3 out of 5 recipients became pregnant at Day 60 and one recipient miscarried at Day 31 after embryo transfer. In conclusion, superovulation improved the production of native Vietnamese pig embryos in vivo, the highest number of repeated superovulation on the native Vietnamese pig breeds was four times and the breed affected the superovulation parameters evaluated. We successfully created pregnant pigs after transferring vitrified-thawed embryos in vivo of native Vietnamese pigs for the first time.

Melatonin preserves ovarian tissues of rats exposed to chronic TCDD: An electron microscopic approach to effects of TCDD on ovarian cells.

2,3,7,8-Tetrachlorodibenzo- p-dioxin (TCDD) is a toxic agent and has disruptive effects on reproductive tissues in females. TCDD disrupts the hormonal regulation of the body and decreases the production of melatonin. In this study, we investigated the protective effects of melatonin supplements against the toxic effects of TCDD on ovaries of female rats. TCDD caused a significant decrease in the average number of corpora lutea and follicles per tissue section (2.1 ± 0.7; 2.3 ± 0.8, respectively), whereas these numbers were maintained in the melatonin supplemented group (5.0 ± 0.8; 5.1 ± 0.8, respectively) and were similar to the control group (5.3 ± 1.0; 5.9 ± 0.9, respectively). Electron microscopic analysis showed that the disruption of ultrastructure components such as cell membrane and organelles due to TCDD exposure was inhibited by melatonin supplements. This study suggested that melatonin has a protective and a possible ameliorative effect over histopathological damage of rat ovaries exposed to TCDD.

Embryo-fetal development toxicity of honokiol microemulsion intravenously administered to pregnant rats

The aim of this study was to evaluate the embryo-fetal development toxicity of honokiol microemulsion. The drug was intravenously injected to pregnant SD rats at dose levels of 0, 200, 600 and 2000 μg/kg/day from day 6–15 of gestation. All the pregnant animals were observed for body weights and any abnormal changes and subjected to caesarean-section on gestation day (GD) 20; all fetuses obtained from caesarean-section were assessed by external inspection, visceral and skeletal examinations. No treatment-related external alterations as well as visceral and skeletal malformations were observed in honokiol microemulsion groups. There was no significant difference in the body weight gain of the pregnant rats, average number of corpora lutea, and the gravid uterus weight in the honokiol microemulsion groups compared with the vehicle control group. However, at a dose level of 2000 μg/kg/day, there was embryo-fetal developmental toxicity observed, including a decrease in the body length and tail length of fetuses. In conclusion, the no-observed–adverse-effect level (NOAEL) of honokiol microemulsion is 600 μg/kg/day, 75 times above the therapeutic dosage and it has embryo-fetal toxicity at a dose level of 2000 μg/kg/day, which is approximately 250 times above the therapeutic dosage.

Melatonin promotes superovulation in sika deer (Cervus nippon).

In this study, the effects of melatonin (MT) on superovulation and reproductive hormones (melatonin, follicle-stimulating hormone (FSH), luteinizing hormone (LH) and PRL) were investigated in female sika deer. Different doses (40 or 80 mg/animal) of melatonin were subcutaneously implanted into deer before the breeding season. Exogenous melatonin administration significantly elevated the serum FSH levels at the time of insemination compared with levels in control animals. During superovulation, the serum LH levels in donor sika deer reached their highest values (7.1 ± 2.04 ng/mL) at the point of insemination, compared with the baseline levels (4.98 ± 0.07 ng/mL) in control animals. This high level of LH was sustained until the day of embryo recovery. In contrast, the serum levels of PRL in the 80 mg of melatonin-treated group were significantly lower than those of control deer. The average number of corpora lutea in melatonin-treated deer was significantly higher than that of the control (p < 0.05). The average number of embryos in the deer treated with 40 mg of melatonin was higher than that of the control; however, this increase did not reach significant difference (p > 0.05), which may be related to the relatively small sample size. In addition, embryonic development in melatonin-treated groups was delayed.

Autumn and winter kidney fat indexes of roe deer does and their correlation with reproductive parameters

I studied the variations of kidney fat indexes (KFI) in two game management units of the Great Hungarian Plain between 2002 and 2004 in the autumn and winter months. I was looking for correlation between the autumn and winter KFI as well as between the autumn KFI and reproductive parameters (number of corpora lutea, recruitment rate).&#x0D; There was a significant positive correlation between the average winter and the average next autumn KFI (r=0.991, p&lt;0.1). The average winter KFI showed strong positive correlation with the average number of corpora lutea (CL) in the next rutting season (r=0.978, p&lt;0.05). The average autumn KFI and the average grown up offspring showed positive but not significant correlation (r=0.725, p=0.275).

Resposta ovariana de cabras submetidas a implantes de progesterona seguidos de aplicações de gonadotrofina coriônica equina

Objetivou-se comparar os efeitos de diferentes doses de gonadotrofina coriônica equina (eCG) na dinâmica folicular e nas concentrações hormonais em cabras alpinas. Durante a estação reprodutiva, as cabras foram submetidas à sincronização do estro e da ovulação com um dispositivo de progesterona por 14 dias. As cabras (n=24) foram divididas aleatoriamente, em quatro grupos de seis e, no dia da remoção do dispositivo, receberam 0 (controle), 200, 300 e 400 UI de eCG. O desenvolvimento folicular foi observado via ultrassonografia um dia antes da administração da eCG até a ovulação seguinte. Determinaram-se diariamente as concentrações plasmáticas de estradiol e progesterona por radioimunoensaio. Todos os animais tratados manifestaram estro. Observaram-se ciclos estrais com três e quatro ondas de crescimento folicular. O tamanho do maior folículo nos animais controle na terceira onda (5,5 ± 0,50 mm) foi menor que naqueles tratados com 300 UI de eCG (7,17 ± 0,35 mm). A aplicação de gonadotrofina aumentou o número de folículos pequenos e médios em relação ao grupo controle, uma vez que o número médio de corpos lúteos foi maior nas fêmeas tratadas com 400 UI (4,27 ± 0,23) em comparação àquelas tratadas com 200 UI (1,95 ± 0,19). A concentração plasmática de progesterona e estradiol diferiu entre os grupos experimentais. A combinação de progestágenos e eCG é uma alternativa adequada para a sincronização do estro e suporta o desenvolvimento de novos protocolos de técnicas reprodutivas, como a superovulação e a transferência de embriões em cabras.

Effect of the El Niño phenomenon on the ovarian responsiveness and embryo production of donor cows.

The effects of different Temperature Humidity Index (THI) values in cold, hot and El Niño (EN) climates on superovulation and embryo production were analysed on Holstein Friesian donor cows. There were significant differences in the THI among the three climates. The average temperature in the EN period was 6 degrees C higher than in the summer period of the previous 30 years. The number of corpora lutea (CL) and embryos were log- and back-transformed, Kolmogorov-Smirnoff test was used for normality and Lilliefors test was applied for significance. In the cold season THI was 70.74 +/- 1.35 and the average number of CL was 9.84 +/- 4.37. In the hot season the THI was 73.99 +/- 0.72 and the average number of CL was 9.70 +/- 4.49. When the THI, in the EN period, increased up to 79.74 +/- 4.01, the superovulation response was significantly (P < 0.01) reduced (average number of CL = 5.22 +/- 2.53). The embryo production result showed a similar tendency. In the hot period the average number of embryos obtained was 5.87 +/- 2.98. However, in the EN period it decreased to 4.21 +/- 2.05. Higher temperature reduced embryo quality. The proportion of live embryos (%) was 59.2 +/- 37.4 in the cold and 38.2 +/- 38.5 in the EN periods of the year (P < 0.01). However, ovarian sensitiveness showed adaptation to summer environment while the heat stress, which was more severe in the EN period, negatively affected the superovulation response and embryo production.

Fertilization and embryo recovery rates in superovulated Chios ewes after laparoscopic intrauterine insemination

Forty superovulated dairy ewes of the Greek Chios breed were used in an experiment to evaluate the efficiency of laparoscopic intrauterine insemination on fertilization and embryo recovery rates as well as embryo quality. Estrus was synchronized by intravaginal progestagen impregnated sponges and superovulation was induced by administration of 8.8 mg o-FSH im following a standard 8 dose protocol. A small volume (0.3mL) of diluted fresh ram semen was deposited in each uterine horn 24 to 28 h after onset of the estrus by a laparoscopic technique. The animals were allocated randomly into two groups (Group A and B) of 20 animals each. In Group A, embryos were recovered 18 to 24 h after the intrauterine insemination and in Group B on Day 6. The average number of corpora lutea was 12.8 ± 1.2 and 11.5 ± 1.1 (± SEM); the overall embryo recovery was 66.4% and 57% and the percentage of recovered fertilized ova was 81% and 82.8% in Groups A and B, respectively. More fertilized ova were collected per ewe from Group A (P ≤ 0.1). Results indicated that in Chios breed, superovulation using homologous FSH combined with laparoscopic AI leads to good ovarian response with satisfactory results in fertilization, embryo recovery and quality of embryos. This could lead to improved and more efficient methods for obtaining large numbers of high quality oocytes and embryos for embryo transfer programs which could contribute to genetic improvement and increase of the population size.

Comparison of Efficiency of PMSG and FSH Treatment for Superovulation in the Same Holstein Cows

The 23 donor cows were administered with 3000 IU of PMSG and a total of 2440 AU FSH followed by PGF2αanalog at about 80 days intervals by turns. Thereafter, the efficacy of the 2 treatments were compared using the same cows on the number of corpora lutea, embryos recovered and returned estrus. The cows treated with PMSG resulted in more corpora lutea than with FSH (11.3 vs 7.5; P<0.05). However, there were no differences between 22 PMSG-treated cows and 17 FSH-treated cows with more than 2 corpora lutea, on the average number of corpora lutea (11.8 vs 10.1), recovered eggs (6.7 vs 6.8), fertilized eggs (5.9 vs 5.4) and normal embryos (4.9 vs 4.6), respectively. Through the experiment, two out of 23 cows showed a poor response (with less than 5 corpora lutea) while 12 cows showed a good response (with more than 6 corpora lutea) in either treatment. On the other hand, the remainders had an opposite response in each treatment. There was no difference between 2 treatments on the days from superovulation to estrus. Consequently, it seems that the efficacy of the next treatment can be predicted from the results of the first treatment.

The relationship between ovulation rate and litter size before and after Day 35 of pregnancy in gilts and sows: An analysis of published data

The relationships between the average number of corpora lutea and the average number of embryos or foetuses and the average prenatal survival rate were studied in data obtained from 78 publications for 139 (sub)populations. Before Day 35 of pregnancy, number of embryos increased linearly with an increase in number of corpora lutea. This increase was significant for non-induced and hormonally induced gilts and sows. In non-induced gilts and sows this increase was still significant after Day 35, but of a lower magnitude. No information was available for induced gilts and sows for the period after Day 35. In non-induced gilts and sows the prenatal survival rate did not change significantly with the number of corpora lutea before Day 35, but decreased significantly with an increasing number of corpora lutea after Day 35. Before Day 35 the latter was also true for the induced gilts and sows. It is concluded that an increase in average ovulation rate can result in an increase of average litter size.

Evidence for transuterine migration of embryos in the domestic cat.

A total of 169 pregnant cats presented for ovariohysterectomy were examined for the number of corpora lutea (CL) and the number of fetuses per uterine horn. The implantation rate and the frequency of occurrence of transuterine migration of embryos were calculated. The average number of CL was 5.6 +/- 1.9 (mean +/- SD; range, 2-11), the average number of fetuses was 4.5 +/- 1.4 (range, 1-8) and the average implantation rate was 84 +/- 20%. Transuterine migration occurred in 69/169 cats (40.8%). In animals with a 100% implantation rate, transuterine migration occurred in 50/84 cats (59.5%). The number of embryos that migrated ranged from 1-3 per animal and embryos moved from the uterine horn ipsilateral to the ovary with the larger number of CL in 66/69 cats (95.7%). As a result of transuterine migration, the difference in the number of fetuses between uterine horns as compared with the difference in the number of CL between ovaries was smaller in 54 casts (78.3%), unchanged in 8 cats (11.6%) and larger in 7 cats (10.1%). These results indicate that cats tend to equalize the number of fetuses between uterine horns by transuterine migration of embryos.

Embryonic survival in the pig after insemination with antigen-enriched semen

Ninety-two first-litter Dutch Landrace sows were inseminated at their first oestrus after weaning with diluted semen containing 2.3 × 10 9 motile sperm cells. Immediately before insemination of 46 randomly chosen sows, 2 × 10 8 fresh bovine leucocytes were added to the semen. All sows were slaughtered on Day 8, 9, or 10 after insemination. In the control group and leucocyte-treated group respectively, 41 and 39 sows were pregnant at slaughter. The average number of corpora lutea (± SEM) in pregnant animals was 15.72 ± 0.60 and 15.22 ± 0.61, respectively. The average number of embryos was 10.66 ± 0.79 and 10.36 ± 0.80, respectively. The addition of bovine leucocytes to semen had neither influence on the pregnancy rate, nor on the number of embryos during early pregnancy.

Multiple births in Schlieffen's bat,Nycticeius schlieffenii(Peters, 1859) (Chiroptera: Vespertilionidae) from the southern African subregion

Nycticeius schlieffenii is a monestrous species that breeds during the spring months in the northern parts of the Kruger National Park. During spring 1983 the average number of corpora lutea in 11 Nycticeius schlieffenii females was 3,1 (range 1-4), with the average number of fetuses recorded 2,8. In the present study this bat has been found to be a polyovular seasonal breeder, giving birth to as many as three young per estrous cycle.

Ovulation rate in induced oestrous cycles of anoestrous ewes given bromocriptine.

The suppression of prolactin in anoestrous ewes by daily injections of bromocriptine reduced the average number of corpora lutea on Day 8 after induced oestrus from 2.8 to 1.6 (P less than 0.02). There was a significant correlation (r = 0.87, P less than 0.05) between the preovulatory peak values for prolactin and ovulation rate in treated but not in control ewes. Bromocriptine failed to prevent the ewes from returning to anoestrus after the induced oestrus.

Reproduction study of Guanabenz, a new antihypertensive agent (1) - fertility test in rats

Guanabenz (WY-8678) was given to rats to examine its effects on their reproductive ability, dams and their fetuses. The drug was administered orally to rats at 30, 15, and 1 mg/kg/day. The vehicle used was 5%-Arabic Gum at dose level of 5 ml/kg, and a control experiment where only vehicle was administered was also conducted. Male rats were treated for 60 days before mating and the treatment continued through mating. Female rats were treated 14 days before mating and the treatment continued from mating to the 7th day of gestation. The results obtained were as follows. 1. In male rats before mating in the 30, 15, and 5 mg/kg groups, the increase of body weight tended to be suppressed, and decrease of food consumption and increase of water intake were found. In female rats before mating in the 30 and 15 mg/kg groups, increase of body weight tended to be repressed, and decrease of food consumption and increase of water intake were found in each group. 2. In the observation of males and females, the drug induced decrease in spontaneous movement, sedation, lacrimation of red exudate and nebula of the eyeball. 3. In the reproduction test, copulations were confirmed in almost all rats by the second cycle of matings. However, the pregnancy rate tended to decrease a little in the 30 and 15 mg/kg groups. 4. Body weight increase during gestation was not affected by oral administration of 1 mg/kg, but was inhibited dose-dependently by administration of more than 5 mg/kg/day of Guanabenz. Food consumption and water intake tended to increase in drug-treated groups. 5. In the observation of the fetuses, the average number of corpora lutea were decreased in the 15 mg/kg group. The average number of implantations decreased in the 30 and 15 mg/kg groups. The implantation rate decreased in the 30 mg/kg group. No difference was observed in each group on the number of resorptions, the number of live fetuses, and the sex ratio. 6. No difference was observed in each group as to external and visceral malformations. In the skeletal observation, retardation of ossification was observed in the 30 mg/kg group. From these results, it is concluded that Guanabenz shows neither fatal effect nor teratogenic potential on fetuses in rats and the safe dosage level seems to be below 5 mg/kg/day.

Annual reproductive rhythm and ovulation rate in four fat-tailed sheep breeds

ABSTRACTKarakul, Mehraban, Naeini and Bakhtiari sheep were checked twice a day for oestrus using aproned rams and were laparotomized within 5 to 16 h of the end of every second oestrous period. Oestrus was observed for 12 monthly periods commencing on 21 April.The Mehraban breed with 1 -6 oestrous periods per month was less seasonal in its breeding activity (P&lt;0·01) than the other breeds. Four-year-old ewes were more sexually active (P&lt;0·01) than 3-year-old ewes (1·48 v. 1·28 oestrous periods per month). Seasonal variation in the sexual activity of the ewes was observed (P&lt;001); the peak of activity in July to January was followed by a steady decline in February and March to a low in April and May, and then a steep recovery phase in June. There was only limited sexual activity for at least 4 months (March to June).The overall mean cycle length was 17·8 days (14 to 23 days), and the means for the four breeds were 17·6, 17·8, 17·8 and 17·9. The oestrous cycle was longer (P&lt;0·05) during the period from December t o February than during that from June to August.The overall mean duration of the oestrous period was 36·9 h and the means for the four breeds were 35·2, 38·0, 37·4 and 37·1 h, respectively (P&lt;0·05). The duration showed some monthly variation (P&lt;0·01) but did not follow a special seasonal pattern. The ovulation rates for the four breeds were 1·07, 1·13,0·94 and 0·95 respectively, (P&lt;0·01). There was a non-significant decline in the mean ovulation rate from March to June. Right ovaries were more active than left ovaries as judged by the observation of a higher average number of corpora lutea per ewe per laparotomy (0·58 v. 0·43, P&lt;001).

Evaluation of the teratogenic potential of tertiary butylhydroquinone (TBHA) in the rat.

Tertiary butylhydroquinone (TBHQ), and approved antioxidant used alone or in combination with other antioxidants produced no teralogenic effects after administration via the diet to pregnant rats at concentration of 0.125, 0.25 and 0.50% during the sensitive period of gestation. The mean body weight and feed consumption of the dams were unaffected. The average number of corpora lutea, implantation sites, viable fetuses, resorptions and fetal body weights and mortality did not differ between the control and treated groups. A significant number of rudimentary ribs were seen in all groups. However, the incidence of this variation was two times greater in the control group than in any treatment group. It is concluded that TBHQ is not teratogenic in rats at 62.5, 125 and 250 times the approved use level for humans.

Egg transfer in the bovine: Effect of injecting PMSG on different days

Sixty one (61) donor animals were inoculated with 500 I.U./100 kg body-weight of Pregnant Mare Serum Gonadotropin (PMSG) on days 9–14 of their oestrous cycle and given 25 mg PGF 2α 48 hrs. later. The superovulatory response to the PMSG injection on different days were evaluated based on the number of corpora lutea (CL) present in both ovaries at the time of surgical ova collection 5 days after standing heat. The average number of CL's was 11,1. The highest number of CL's was observed when PMSG was injected on day 11 (12,5 ± 5,5) and the lowest following day 14 treatment (4,5 ± 3,2). No statistical difference was found between days 9–10–11, 12 and 13. The results suggest that a certain “day of injection variation” may exist and contribute to the umpredictability of PMSG treatments.

EMBRYONIC MORTALITY AND DEVELOPMENT DURING EARLY PREGNANCY IN THREE BREEDS OF SWINE WITH PUREBRED AND CROSSBRED LITTERS

Data on ovulation rate, litter size, fetal and placental weights and weight and length of uterine horns were taken at 23, 42 or 63 days of pregnancy on 138 Yorkshire, Landrace and Lacombe multiparous sows bred to Yorkshire, Landrace and Hampshire boars to produce purebred and crossbred litters. Of the 53 Yorkshire sows slaughtered, 13.2% were non-pregnant, compared to 7.5 and 8.5% for the Landrace and Lacombe sows, respectively. The average number of corpora lutea was 15.1 in Landrace, one more than in Lacombe and Yorkshire sows. Embryonic mortality in crossbred litters was 7.5 and 6.0% higher in Landrace sows than in Yorkshire and Lacombe sows, respectively. In purebred litters, it was 8.4% higher in Landrace than in Yorkshire. Litters sired by Yorkshire boars were 7.8% larger in number than those sired by Landrace or Hampshire boars. At 23 days of pregnancy, 19% of the ova released in the three breeds were lost. A further loss of 4% was noted at later stages. The weights of Landrace and Lacombe embryos were significantly (P &lt; 0.05) heavier than those of Yorkshire at the 3 days of pregnancy studied. Crossbred embryos of Yorkshire and Landrace were heavier than purebreds by 27, 8 and 6% at the 23, 42 and 63 days of pregnancy, respectively. Weights of the uterine horns and placental membranes were heavier in Landrace and Lacombe than in Yorkshire sows. Little difference was found between Landrace and Lacombe breeds in embryonic, placental and uterine weights. Highly significant correlations (r = 0.65, 0.57 and 0.76) were found between placental and embryonic weights at the 3 days of pregnancy. Correlation between number of viable embryos and length of uterine horn was 0.30 and that with weight of horn was 0.10.