Influence of rams on ovarian activity and oestrus in Merino ewes in the spring and early summer

1957 ◽  
Vol 8 (5) ◽  
pp. 460 ◽  
Author(s):  
HM Radford ◽  
RH Watson
Keyword(s):  
Epithelial Cells ◽  
Early Summer ◽  
Vaginal Epithelium ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Group 4 ◽  
Group 6 ◽  
Almost All

The occurrence of oestrus and ovulation and the changes in the vaglnal contents were studied in Merino ewes following the introduction of vasectomized rams at various times during the spring and early summer. The ewes were in an anoestrous state when the observations were commenced. Except in occasional ewes oestrus did not appear until early December. It had occurred in all except a few ewes by early January. In most ewes among which rams were introduced on October 26 or November 18, it occurred about a week earlier than in ewes among which rams mere not introduced until December 8, and ewes among which rams had been running continuously. In at least 80 per cent, of animals in which both were studied, oestrus was accompanied by massive desquamation of the vaginal epithelium and it was preceded by one or more periods of massive desquamation. Between December 8 and December 14, masses of desquamated epithelial cells were present in the vaginal contents in few only of the ewes which were held separate from rams, but in almost all ewes among which rams were introduced on December 8 (group 4), and in most of the em7es which were running continuously with rams (group 6). They first appeared in the ewes of group 4 between December 11 and December 14, 3-6 days after the introduction of the rams, whereas they were already present in almost all of the ewes of group 6 by December 11.Corpora lutea compatible with ovulation shortly after December 8 were present in most ewes among which rams were introduced on that day, and in few ewes which were held separate from rams. The significance of these results is discussed.

Early Embryonic Development and Ovarian Activity During Concurrent Pregnancy and Lactation in the Hopping-Mouse Notomys Alexis.

1981 ◽  
Vol 29 (4) ◽  
pp. 589 ◽  
Author(s):  
WG Breed
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Embryonic Development ◽  
Steroid Hormone ◽  
Synthetic Activity ◽  
Luteal Cell ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Pregnancy And Lactation ◽  
Further Development

In the hopping-mouse, following a postpartum mating, embryos enter the uterus on about day 5. Implantation occurs on about day 7 if there are no suckling pups, but zona-free blastocysts may remain up to day 18 if from four to seven suckling pups are present. Implantation is eccentric and initially involves interdigitation of trophectoderm and uterine epithelial cells, followed by epithelial cell displacement. The orientation is antimesometrial and, during further development, the embryo invaginates into the yolk-sac cavity. In the ovary, corpora lutea develop during the first few days of pregnancy and then remain unchanged in size or cellular morphology until implantation, regardless of the length of its delay. Peripheral progesterone levels likewise show little change during the preimplantation period. After implantation, a similar number of corpora lutea are found but they increase progressively in size due to luteal cell hypertrophy. The cells show all the organelles typical of steroid hormone synthetic activity and there is a corresponding increase in blood progesterone levels at this time. Vesicular follicles are present throughout concurrent pregnancy and lactation and are larger after implantation. There is no evidence of spontaneous ovulation except at the time of parturition.

scholarly journals Association between serum oestradiol level on the hCG administration day and neonatal birthweight after IVF-ET among 3659 singleton live births

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Liu ◽  
Jing Li ◽  
Wanyu Zhang ◽  
Yihong Guo
Keyword(s):  
Birth Weight ◽  
Ovarian Stimulation ◽  
Group 4 ◽  
Group 6 ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
The Impact ◽  
Ivf Et ◽  
Group 1

AbstractOestradiol, an important hormone in follicular development and endometrial receptivity, is closely related to clinical outcomes of fresh in vitro fertilization-embryo transfer (IVF-ET) cycles. A supraphysiologic E2 level is inevitable during controlled ovarian hyper-stimulation (COH), and its effect on the outcome of IVF-ET is controversial. The aim of this retrospective study is to evaluate the association between elevated serum oestradiol (E2) levels on the day of human chorionic gonadotrophin (hCG) administration and neonatal birthweight after IVF-ET cycles. The data of 3659 infertile patients with fresh IVF-ET cycles were analysed retrospectively between August 2009 and February 2017 in First Hospital of Zhengzhou University. Patients were categorized by serum E2 levels on the day of hCG administration into six groups: group 1 (serum E2 levels ≤ 1000 pg/mL, n = 230), group 2 (serum E2 levels between 1001 and 2000 pg/mL, n = 524), group 3 (serum E2 levels between 2001 and 3000 pg/mL, n = 783), group 4 (serum E2 levels between 3001 and 4000 pg/mL, n = 721), group 5 (serum E2 levels between 4001 and 5000 pg/mL, n = 548 ), and group 6 (serum E2 levels > 5000 pg/mL, n = 852). Univariate linear regression was used to evaluate the independent correlation between each factor and outcome index. Multiple logistic regression was used to adjust for confounding factors. The LBW rates were as follows: 3.0% (group 1), 2.9% (group 2), 1.9% (group 3), 2.9% (group 4), 2.9% (group 5), and 2.0% (group 6) (P = 0.629), respectively. There were no statistically significant differences in the incidences of neonatal LBW among the six groups. We did not detect an association between peak serum E2 level during ovarian stimulation and neonatal birthweight after IVF-ET. The results of this retrospective cohort study showed that serum E2 peak levels during ovarian stimulation were not associated with birth weight during IVF cycles. In addition, no association was found between higher E2 levels and increased LBW risk. Our observations suggest that the hyper-oestrogenic milieu during COS does not seem to have adverse effects on the birthweight of offspring after IVF. Although this study provides some reference, the obstetric-related factors were not included due to historical reasons. The impact of the high estrogen environment during COS on the birth weight of IVF offspring still needs future research.

Timing of melatonin treatment: differential effects on oestrus and coat growth in goats

1997 ◽  
Vol 65 (2) ◽  
pp. 267-273 ◽  
Author(s):  
I. A. Forsyth ◽  
F. E. Gebbie ◽  
J. Arendt
Keyword(s):  
Goat Milk ◽  
Normal Weight ◽  
Ovarian Activity ◽  
Plasma Prolactin ◽  
Dairy Goats ◽  
Group 4 ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Group 1

AbstractTo avoid winter scarcity of fresh goat milk, simple methods of advancing the season of kidding would be commercially valuable. A combination of long-day light treatment followed by melatonin is successful but other aspects of seasonality including coat growth are also reset. To investigate whether effects on breeding season and coat growth can be dissociated, British Saanen dairy goats (no. = 30) were randomly allocated to one of six groups. Control goats were untreated. Goats in the other five groups received 2 months of treatment with 20 h light: 4 h darkness (20L: 4D) and were then given 3 mg melatonin orally at 16.00 hfor 2 months. The treatments started on 11 January (group 1), 29 March (group 2), 14 June (group 3), 30 August (group 4) and 8 November (group 5). Weekly blood samples were taken for the measurement of progesterone to monitor ovarian activity and prolactin. Side patches (10 cm ×10 cm) were clipped monthly from alternate sides and weighed to measure coat growth. The onset of ovarian activity was advanced from a median date of 15 November in controls to 24 May in group 1 (P < 0·01), 16 August in group 2 (P < 0·05) and 18 October in group 3 (? < 0·05). Groups 4 and 5 showed no significant change in the onset of oestrus (median onset dates 8 November and 1 November, respectively). Group 1 goats came into season again with controls in November. In all except group 5, treatment interacted with time to affect significantly the growth of the coat. The pattern of coat growth was most altered (P < 0·001) in groups 1 and 2. This was associated with effects on plasma prolactin concentrations of light stimulation and melatonin suppression. Group 1 goats resynchronized with control goats to show a coat of normal weight in the winter following treatment. Division of milking goat herds into spring and autumn kidding groups is, therefore, a practical possibility, but effects on overall milk yield require study.

scholarly journals Metabolic Attributes, Milk Production and Ovarian Activity of Ewes Supplemented with a Soluble Sugar or a Protected-Fat as Different Energy Sources During Postpartum Period

2017 ◽  
Vol 17 (1) ◽  
pp. 229-240 ◽  
Author(s):  
Nesrein M. Hashem ◽  
Samir Z. El-Zarkouny
Keyword(s):  
Milk Production ◽  
Postpartum Period ◽  
Serum Insulin ◽  
Soluble Sugar ◽  
Body Weight Loss ◽  
Experimental Period ◽  
Energy Sources ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Serum Triglycerides

Abstract The effects of two dietary supplemental energy sources on metabolic attributes, milk production and ovarian activity of ewes during early to mid-postpartum period were studied using thirty multiparous lactating ewes (Rahmani × Barki) weighing 43.10±1.22 kg and 3-6 years old. The ewes were assigned to three groups (n=10 per group). All ewes received the same diet supplemented with isocaloric and isonitrogenous protected-palm oil (50 g/ewe/d, F-group) or a sugar cane molasses (140 g/ewe/d, M-group) or without supplementation (control, C-group), for 60 days starting 2 weeks postpartum. Results showed that, during the experimental period, both energy sources reduced (P<0.05) body weight loss of ewes compared with the control (2.57 kg in F-group, 0.911 kg in M-group and 4.71 kg in C-group). The metabolic profiles of ewes were affected by the sources of energy, the highest (P<0.05) concentration of serum triglycerides was in the F-group, whereas the highest (P<0.05) concentration of serum insulin was in the M-group. The lowest serum glucose concentration was (P<0.05) in the F-group (73.20 mg/dL) and the highest in the C-group (76.85 mg/dL), whereas it was intermediate in the M-group (74.69 mg/dL). Ewes in the F-group had (P<0.05) the highest milk yield and energy-corrected milk (531.72 g/d and 554.40 g/d, respectively) compared with those in the M-group (491.76 g/d and 525.12 g/d, respectively) and C-group (429.96 g/d and 462.00 g/d, respectively). The highest (P<0.05) number of corpora lutea (CL; ovulation activity) was in the F-group (0.45), whereas it was not different between the M-group (0.25) and the C-group (0.15). In conclusion, during early to mid-postpartum period, protected-fat supplementation increased serum triglycerides concentration which was effectively used as an energyyielding nutrient for improving milk production. It could also be suggested that specific fatty acid in protected-fat improved quality of the ovulatory follicle and thus occurrence of ovulation.

ENDOCRINE PROFILES AND FUNCTIONAL CHARACTERISTICS OF CORPORA LUTEA FOLLOWING ONSET OF POSTPARTUM OVARIAN ACTIVITY IN BEEF COWS

1983 ◽  
Vol 63 (2) ◽  
pp. 331-347 ◽  
Author(s):  
J. G. MANNS ◽  
W. D. HUMPHREY ◽  
P. F. FLOOD ◽  
R. J. MAPLETOFT ◽  
N. RAWLINGS ◽  
...  
Keyword(s):  
Light And Electron Microscopy ◽  
Beef Cows ◽  
Luteal Cell ◽  
Cell Diameter ◽  
Rapid Decline ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Functional Characteristics ◽  
Blood Samples ◽  
Endocrine Profiles

Three experiments were conducted to evaluate endocrine profiles and to determine the morphological and functional characteristics of corpora lutea (CL) following the onset of postpartum ovarian activity in beef cows, suckled by a single calf once daily. In exp. 1, blood samples were collected from 12 cows at 6-h intervals beginning 25 days postpartum until ovariectomy which was carried out on each of two cows on days 25, 27, 29, 31, 33, 35 after parturition. Ovarian structures were examined grossly and histologically. In exp. 2, blood samples were collected from eight cows at 6-h intervals for 18 days beginning 25 days postpartum and at less frequent intervals thereafter. Laparotomies were carried out on day 36 after calving, the ovaries were observed, CL were sampled and the residual tissue was marked with charcoal. A second laparotomy was performed on day 50. Luteal tissue samples were processed and examined by light and electron microscopy. Luteal cell types were evaluated, percent of area covered by large cells was determined and average luteal cell diameter was calculated. In exp. 3, seven cows were bled daily from parturition until day 25 postpartum. Serum from all experiments was assayed for progesterone (P4), FSH, LH and a prostaglandin metabolite (PGFM). The data showed that serum PGFM levels declined from a peak at calving to basal levels by 10 days postpartum which was well before the first ovulation. In all instances the observed peaks of serum LH and serum FSH preceded the first rise in P4 which, in eight of nine cases, was due to a functional CL. These CL were functional for periods of time ranging from 3 to 12 days. The regression of short-lived CL appeared abnormal compared to the longer-lived CL in which regression was characterized by a rapid decline in P4 and elevated blood PGFM. These data show clearly that the first increase in P4 is preceded by a typical LH surge, followed by ovulation and CL formation which has a variable life-span. Key words: Beef cows, postpartum, anestrus, corpus luteum.

Seasonal differences in ovarian activity in cows

1984 ◽  
Vol 102 (2) ◽  
pp. 189-198 ◽  
Author(s):  
K. P. McNatty ◽  
N. Hudson ◽  
M. Gibb ◽  
K. M. Henderson ◽  
S. Lun ◽  
...  
Keyword(s):  
Granulosa Cells ◽  
Ovarian Function ◽  
Plasma Concentrations ◽  
Peak Frequency ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Aromatase Activity ◽  
Plasma Prolactin ◽  
Seasonal Differences ◽  
Time Of Year

ABSTRACT The plasma concentrations of LH and prolactin and various parameters of ovarian function were examined in cows on known days of the oestrous cycle during May and June (autumn and winter) and during October (spring). Luteinizing hormone peak frequency and plasma prolactin concentrations were significantly higher in October than during the May–June period (LH, P<0·05; prolactin, P<0·01). The mean diameters of large healthy follicles (≥8 mm diameter) and the dominant oestrogen-secreting follicles were significantly larger (P<0·01 for both follicle types) and each follicle contained more granulosa cells (both P<0·01) in May–June than in October. The LH responsiveness of theca interna with respect to androstenedione production and the levels of aromatase activity in granulosa cells did not differ with time of year. The corpora lutea were heavier (P<0·05) and secreted more progesterone (P<0·01) in May–June than in October. It is concluded that seasonal differences in ovarian activity exist in cows and that these differences are probably the consequence of seasonal differences in gonadotrophin secretion. J. Endocr. (1984) 102, 189–198

Genetic analysis of developmental mechanisms in hydra. V. Cell lineage and development of chimera hydra

1978 ◽  
Vol 32 (1) ◽  
pp. 215-232
Author(s):  
T. Sugiyama ◽  
T. Fujisawa
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Interstitial Cell ◽  
Cell Lineage ◽  
Interstitial Cells ◽  
Nerve Cells ◽  
Polyp Size ◽  
Primary Determinant ◽  
One Year ◽  
Almost All

Chimeric hydra were produced by making use of a strain (nf-1) which lacks interstitial cells, nerve cells and nematocytes. This strain arises by spontaneous loss of interstitial cells from its parental strain (sf-1) (Sugiyama & Fujisawa, 1978). Reintroduction of interstitial cells from other strains into nf-1 leads to the creation of chimeric strains that consisted of epithelial cells derived from strain sf-1 and interstitial cells and their derivatives (nerves and nematocytes) from other strains. In chimeras, interstitial or epithelial cells apparently maintain very stable cell lineages; no indication was obtained that suggested interstitial cell differentiation into epithelial cells or dedifferentiation in the opposite direction during the long courses of chimera cultures (up to one year). Developmental characters of chimeras were examined and compared to those of the epithelial cell (sf-1) and the interstitial cell donors. Almost all of the chimera's characters examined (growth rate, budding rate, tentacle numbers, polyp size, regenerative capacity, etc.) closely resembled those of the epithelial cell donor, but not of the interstitial cell donors. This suggests that epithelial cells, rather than interstitial or nerve cells, are the primary determinant of most, if not all, of hydra developmental characters.

Effects of calcium salts of fatty acids on follicular characteristics and several blood parameters in two fat-tailed sheep breeds

2002 ◽  
Vol 2002 ◽  
pp. 131-131
Author(s):  
M. J. Zamiri ◽  
E. Rowghani ◽  
S. M. Ghoreishi
Keyword(s):  
Fatty Acids ◽  
Plasma Cholesterol ◽  
Post Partum ◽  
Reproductive Function ◽  
Blood Parameters ◽  
Dietary Lipid ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Luteal Function ◽  
Sheep Breeds

There is substantial evidence that the increased consumption of fat by dairy cattle can result in an increase in the number ovarian follicles, and the number and size of corpora lutea; it also stimulates post-partum ovarian activity and improve pregnancy rate. Increased dietary lipid also increases plasma cholesterol and progesterone, and the supply of lipoproteins which play significant roles in regulating ovarian steroidogenesis (Willimas, 1996). In contrast to cattle, there are few observations on the effects of dietary lipid on reproductive function in sheep. Intravascular infusion of lipid into ewes stimulated progesterone and prostaglandin synthesis (Burke et al., 1996), and dietary supplementation of calcium soaps of fatty acids enhanced luteal function (Kuran et al., 1999). Calcium soaps of fatty acids have been manufactured in Iran in recent years and sold under the trade name of Megalac. The aim of the present experiment was to study the effects of this protected fat on follicular number and luteal activity in two fat-tailed sheep breeds.

Development in calves and heifers after hypophysial stalk transection or hypophysectomy.

1977 ◽  
Vol 232 (5) ◽  
pp. E497
Author(s):  
L L Anderson
Keyword(s):  
Epithelial Cells ◽  
Sexual Development ◽  
Follicular Development ◽  
Seminal Vesicles ◽  
Corpora Lutea ◽  
Gonadal Function ◽  
Ovarian Weight ◽  
Thyroid Glands ◽  
Estrous Behavior ◽  
Sexually Mature

Growth was inhibited markedly in prepuberal bull and heifer calves after either hypophysial stalk transection or hypophysectomy as compared with that found in sham-operated calves or in unoperated calves. Male mounting behavior and evidence of puberal estrous behavior were lost or undetected after hypophysial stalk transection or hypophysectomy. Testes regressed, contained few spermatogonia and interstitial cells, and lacked spermatogenesis. Epithelial cells of seminal vesicles, bulbourethral glands, and prostate were cuboidal, indicating inadequate testicular androgen. Atresia of numerous ovarian follicles and reduced ovarian weight occurred in hypophysectomized heifer calves. Graafian follicles regressed after hypophysial stalk transection of sexually mature heifers, but ovaries responded to pregnant mare serum and human chorionic gonadotropin by follicular development, ovulation, and formation of multiple corpora lutea. Thyroid and adrenal gland weights decreased and adrenal cortices atrophied after hypophysectomy, but not after stalk transection. Thyroid glands contained colloid-filled follicles with flattened epithelial cells; atrophy was more extensive after hypophysectomy. Hypophysial stalk transection or hypophysectomy severely depresses growth and arrests sexual development in young calves, but in mature animals exongenous gonadotropins can sustain gonadal function.

PLASMA PROGESTERONE LEVELS IN CYCLING AND GONADOTROPHIN–PROSTAGLANDIN-TREATED HEIFERS

1976 ◽  
Vol 56 (1) ◽  
pp. 37-42 ◽  
Author(s):  
R. RAJAMAHENDRAN ◽  
P. C. LAGUË ◽  
R. D. BAKER
Keyword(s):  
Peak Level ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Dairy Heifers ◽  
The Mean

Progesterone levels were estimated by radioimmunoassay in blood samples obtained by venipuncture on the day of estrus and every alternate day until the onset of the next estrus in eight cycling dairy heifers. The mean level of progesterone was < 1 ng/ml during the first 2 days of the cycle, increased rapidly over the 4th–12th day period and reached a peak level value of 5.2 ± 1.1 ng/ml on day 14. Thereafter, the level declined rapidly to 2.6 ± 0.6 ng/ml on day 16 and then more gradually to 0.4 ± 0.1 ng/ml on day 21. In the second experiment, eight cycling heifers at diestrus were treated with gonadotrophin (2,000 IU PMSG or 1,000 IU PMSG + 1,000 IU HCG) followed 48 h later by 15 mg prostaglandin (PGF2α). Mid-ventral laparotomies were performed 4 days after the onset of estrus to observe ovarian activity. Progesterone levels were considerably higher in some animals and were slightly higher on the average after gonadotrophin treatments. The number of corpora lutea (CL) in these heifers ranged from 1 to 17. Progesterone levels of three heifers with 4–9 CL did not differ (P > 0.05) from those of three heifers with single CL. Two heifers each with 17 CL had peak progesterone levels of 38.4 and 27.8 ng/ml which were still high (9.6 and 26.5 ng/ml) by day 21. The remaining six heifers had low progesterone levels (< 1 ng/ml) by days 8–14, indicating premature regression of the CL. Thus, progesterone levels were not correlated with the number of CL.

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