Seasonal influence on ovarian activity: Winter anestrus and transition to cyclic activity

SummaryLongitudinal studies involving weekly measurement of urinary oestrogen and pregnanediol excretion were performed in 55 post-partum women to identify the patterns of returning fertility. The women kept diaries of breast-feeding episodes, mucus symptoms and times of bleeding; some recorded basal body temperature and acts of intercourse. The study represented a total time of 36 years (7·8 months per woman). The majority of the women were breast-feeding throughout the study. During lactation amenorrhoea, there was complete ovarian quiescence in two-thirds of the subjects and minimal cyclic activity in the others. The first bleeds were associated with anovulatory ovarian activity in 40% of the women, with normal ovulation in 19%, with ovulation but short luteal phases in 25% and with ovulation but deficient luteal phases in 16%. The incidence of normal ovulatory cycles increased with time after delivery and with the number of cycles after delivery and eventually reached 85% even though many women were still breast-feeding at the time. Twenty-two pregnancies occurred, fourteen being unplanned: eight women were fully breast-feeding at the time of conception. Mucus symptoms correlated with the hormone values in approximately 60% of cycles. However, some women had symptoms which were difficult to interpret during their early cycles or potential fertility was not indicated by raised mucus scores or the presence of the peak mucus symptom. These problems together with the resulting confusion appeared to be the major causes for the unplanned pregnancies. Methods for coping with these problems are discussed.

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Induction of puberty in gilts 2. The effect of boars on maintenance of cyclic activity in gilts induced to ovulate with pregnant mare's serum gonadotrophin and human chorionic gonadotrophin

Animal Science ◽

10.1017/s0003356100024764 ◽

1981 ◽

Vol 32 (1) ◽

pp. 51-54 ◽

Cited By ~ 16

Author(s):

A. M. Paterson ◽

D. R. Lindsay

Keyword(s):

Chorionic Gonadotrophin ◽

Human Chorionic Gonadotrophin ◽

Ovulation Rate ◽

Ovarian Activity ◽

Corpora Lutea ◽

Cyclic Activity

ABSTRACTIn two experiments prepubertal gilts were injected with a combination of 400 international units pregnant mare's serum gonadotrophin and 200 international units human chorionic gonadotrophin. The gilts were housed either in contact with or isolated from mature boars. Data were obtained of ovarian activity determined immediately after gonadotrophin treatment and at the anticipated time of the second oestrus.All treated gilts ovulated in response to the treatment and 83% displayed oestrus. Ovulation rate varied both within and between experiments, in experiment 1 the range being 7 to 19 corpora lutea and in experiment 2, between 5 to >30 corpora lutea. Four distinct types of behaviour were observed at the time of the second cycle: ovulation associated with oestrus; ovulation without oestrus; oestrus but no ovulation; and a return to a prepubertal state with no oestrus or ovulation. The presence of boars enhanced the maintenance of cyclic activity. Overall, more gilts displayed a second oestrus (33/39 v. 19/41, X2 = 11·2, P<0·001), and more had a second ovulation (32/39 v. 24/41, X2=4·2, P<0·05) when boars were run with the gilts.

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Investigating Post-partum Ovarian Cyclicity Following Various Treatments in Dairy Cows

Rural Sustainability Research ◽

10.2478/plua-2019-0004 ◽

2019 ◽

Vol 41 (336) ◽

pp. 22-25

Author(s):

Akshay Sharma ◽

Madhumeet Singh ◽

Pravesh Kumar ◽

Pradeep Kumar Dogra

Keyword(s):

Dairy Cows ◽

Corpus Luteum ◽

Body Condition Score ◽

Post Partum ◽

Control Group ◽

Ovarian Activity ◽

Complete Regression ◽

Dominant Follicle ◽

Cyclic Activity ◽

Follicle Diameter

Abstract The present study envisages the effect of PGF2α and antibiotic treatment on ovarian cyclic activity and regression of corpus luteum verum in post-partum dairy cows. Cows were divided into three treatment (PG8, PG25, antibiotic) and a control group. Ovarian activity was studied by examining follicular dynamics upto 42 days post-partum in which diameter of dominant follicle before first ovulation, the number of days to first ovulation and complete regression of corpus luteum verum were evaluated. Body condition score was recorded for all the cows in different groups. Also, ovulation on ovary ipsilateral or contralateral to previous gravid uterine horn was noted. On transrectal ultrasonography at a 3-day interval, dominant follicle diameter prior to ovulation was significantly higher (p<0.01) in PG8 group. The mean time required for complete regression of CL verum was not significantly (p>0.05) lower in PG8 group i.e. 24.33±1.48 days in comparison to PG25, antibiotic and control group (26.67±1.48, 29.00±1.81and 27.60±1.40 days post-partum, respectively). A subsequent ovarian activity was affected as 70.83 and 66.33% Ist and IInd ovulations occurred on the ovary contralateral to corpus luteum verum. In conclusion, contralateral ovary was more active in terms of ovulation whereas presence of corpus luteum verum had no effect on post-partum ovarian cyclic activity.

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EFFECT OF PROGESTERONE AND TEMPORARY WEANING ON CYCLIC ACTIVITY AND FERTILITY OF BEEF COWS AT A PROSTAGLANDIN- SYNCHRONIZED ESTRUS

Canadian Journal of Animal Science ◽

10.4141/cjas83-040 ◽

1983 ◽

Vol 63 (2) ◽

pp. 325-330 ◽

Cited By ~ 4

Author(s):

J. G. MANNS ◽

W. D. HUMPHREY ◽

J. R. NKUUHE

Keyword(s):

Key Words ◽

Beef Cows ◽

Ovarian Activity ◽

Moderate Increase ◽

Short Term ◽

Cyclic Activity ◽

Estrous Cycles ◽

Prostaglandin F ◽

Calf Removal

Three experiments were conducted to assess the effect of short-term calf removal (CR) or treatment with progesterone (P4) on onset of cyclic ovarian activity and fertility in beef cows suckled by a single calf. Estrous cycles of all cows were synchronized by two injections of a prostaglandin F (PGF) analogue 11 days apart. The cows were inseminated at 68 and 92 h after the second PGF injection. In exp. 1, calf removal for 48 h after the second injection of PGF did not alter fertility compared to controls. In exp. 2, cows were treated with 100 mg P4 at the time of the first PGF injection. P4 increased the number of cycling animals by 7% and fertility by 13%, but the differences were not significant. In exp. 3, combinations of CR and P4 were used. When these latter data were summarized and pooled with similar groups from previous experiments, P4 increased cyclic ovarian activity by 9% (P < 0.07) and fertility by 14% (P < 0.04). The results indicate that treatment with P4 caused a moderate increase in onset of cyclic ovarian activity and significantly increased fertility. Key words: Beef cows, postpartum anestrus, progesterone

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The use of a synthetic progesterone, levonorgestrel (LNG), to control the oestrous cycle in the koala

Reproduction Fertility and Development ◽

10.1071/rd14387 ◽

2016 ◽

Vol 28 (10) ◽

pp. 1526 ◽

Cited By ~ 7

Author(s):

K. Ballantyne ◽

S. T. Anderson ◽

M. Pyne ◽

V. Nicolson ◽

A. Mucci ◽

...

Keyword(s):

Epithelial Cells ◽

Implant Removal ◽

Saline Control ◽

Ovarian Activity ◽

Saline Injection ◽

Cyclic Activity ◽

Ovulatory Follicle ◽

Plasma Oestradiol ◽

Implantation Period ◽

Synthetic Progestogen

This study investigated the efficacy of a synthetic progestogen, levonorgestrel (LNG), to control koala ovarian activity for the purposes of oestrous synchronisation. Captive koalas were administered either saline control or a 70-mg LNG implant on Day 2 of oestrus. Urogenital cytology, oestrous behaviour and plasma oestradiol-17β and LH concentrations were monitored over a 6-week period. After LNG implant removal females were monitored to determine if the return to oestrus was synchronised. LNG-treated koalas immediately ceased displaying oestrous behaviour, showed no evidence of cornified epithelial cells in smears of urogenital cytology and exhibited low plasma oestradiol-17β concentrations throughout the implantation period. In contrast, oestradiol-17β levels in control koalas showed evidence of continued cyclic activity associated with behavioural oestrus and increased cornified epithelial cells in urogenital smears on Days 33 to 35 after saline injection. After implant removal, LNG-treated koalas exhibited oestrus at 13, 14, 17 and 30 days after implant removal. Plasma LH concentrations varied throughout the study period with no significant time (P = 0.49) or treatment (P = 0.13) effect. Overall results from this study suggest that LNG implants in koalas can inhibit oestrous behaviour and reduce circulating oestradiol-17β levels before oestrus, most likely by preventing development of the pre-ovulatory follicle. However, there was no evidence of LH suppression by the LNG implants. Removal of LNG implants resulted in the synchronous return to oestrus in three of the four treated koalas. Further studies on a larger population are required to validate these findings.

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The use of a GnRH vaccine to suppress mare ovarian activity in a large group of mares under field conditions

Wildlife Research ◽

10.1071/wr07136 ◽

2008 ◽

Vol 35 (6) ◽

pp. 548 ◽

Cited By ~ 21

Author(s):

A. E. Botha ◽

M. L. Schulman ◽

H. J. Bertschinger ◽

A. J. Guthrie ◽

C. H. Annandale ◽

...

Keyword(s):

Animal Health ◽

Primary Vaccination ◽

Field Conditions ◽

Ovarian Activity ◽

Progesterone Concentration ◽

Cyclic Activity ◽

Active Immunisation ◽

Serum Progesterone ◽

Large Group ◽

Age Related

The aim of this study was to evaluate the effect of active immunisation against GnRH on ovarian activity and serum progesterone concentrations in a large group of mares (10 control and 55 experimental) under field conditions as a model for wildlife species such as zebra and African elephants. Within the experimental group, mares were subdivided into three age categories: Category 1 (4 years and younger, n = 26), Category 2 (4–10 years old, n = 18), and Category 3 (≥11 years old, n = 11). Experimental mares were vaccinated intramuscularly with 2 mL (400 μg) of the GnRH vaccine Improvac (Pfizer Animal Health, Sandton, South Africa). Control mares received the same amount of saline solution. The vaccinations were repeated 35 days later. The ovaries and reproductive tracts of each mare were examined by means of rectal palpation and ultrasonography on Days 0, 35 and 70. Blood was collected weekly for determination of serum progesterone concentration until Day 175. On Day 35 after primary vaccination all of the control mares and 14.5% of the experimental mares showed evidence of ovarian activity on the basis of clinical examination and serum progesterone concentration. On Day 70, all control mares and none of the experimental mares showed evidence of cyclic activity. No age-related effect within treatment groups was found. The serum progesterone concentration indicated that all experimental mares remained in anoestrus until Day 175. Five of the control mares fell pregnant between Days 35 and 70. The five non-pregnant control mares continued to cycle until the end of the observation period. Having achieved such promising results in this trial we now plan to test the GnRH vaccine in Burchell’s zebra mares and African elephant cows.

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Effects of long-term treatment with LH on induction of cyclic ovarian activity in seasonally anoestrous ewes

Journal of Endocrinology ◽

10.1677/joe.0.1000067 ◽

1984 ◽

Vol 100 (1) ◽

pp. 67-73 ◽

Cited By ~ 10

Author(s):

K. P. McNatty ◽

N. Hudson ◽

M. Gibb ◽

K. Ball ◽

J. Fannin ◽

...

Keyword(s):

Plasma Concentrations ◽

Term Treatment ◽

Oestrous Cycle ◽

Ovarian Activity ◽

Cyclic Activity ◽

Long Term Treatment ◽

Term Administration ◽

Term Maintenance

ABSTRACT The aim of the present study was to establish whether cyclic ovarian activity could be induced and then maintained in anoestrous Romney ewes by the long-term administration of regular intravenous pulses of LH (10 μg ovine LH i.v. once every 1 or 2 h for 29–91 days). The LH pulse regimen was designed to generate plasma profiles of LH that were comparable to those experienced during the luteal and follicular phases of the oestrous cycle. The results showed that the LH treatments were capable of inducing cyclic ovarian activity, as assessed from the concentrations of progesterone in plasma, but that the treatments were inadequate for sustaining cyclic activity beyond two consecutive progestational phases. After 35–56 days of treatment, the plasma concentrations of FSH declined significantly (P <0·05) relative to those in the untreated animals. These data suggest that FSH supplementation as well as LH might be required for the long-term maintenance of cyclic ovarian activity in seasonally anoestrous ewes. J. Endocr. (1984) 100, 67–73

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