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

2016 ◽  
Vol 28 (10) ◽  
pp. 1526 ◽  
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.

13 STRATEGIES TO INCREASE OVULATORY FOLLICLE SIZE AND REDUCE OVULATION TIME IN LACTATING DAIRY COWS

2008 ◽  
Vol 20 (1) ◽  
pp. 87
Author(s):  
J. O. Giordano ◽  
J. L. Edwards ◽  
G. M. Schuenemann ◽  
N. Rohrbach ◽  
F. N. Schrick
Keyword(s):  
Oocyte Maturation ◽  
Elevated Temperatures ◽  
Animal Health ◽  
Ovarian Activity ◽  
Blastocyst Development ◽  
Sterile Saline ◽  
Ovulatory Follicle ◽  
To Receive

In vitro exposure of oocytes to elevated temperatures hastened oocyte maturation; furthermore, performing IVF of heat-stressed oocytes 5 h earlier than the usual 24 h resulted in blastocyst development similar to that of non-heat-stressed controls (Edwards et al. 2005 J. Dairy Sci. 88, 4326–4333). If elevated ambient temperatures in vivo alter oocyte maturation in a similar fashion, then new strategies are needed to induce earlier release of the oocyte from the ovulatory follicle. Current objectives were to examine follicular growth after FSH administration and examine whether treatment with FSH and an exogenously induced LH surge would hasten ovulation. On Day 0 (8 to 9 days after estrus) of the experimental period, lactating Holstein cows (n = 31; 65–115 days in milk; 1–6 lactations) received an EAZI-BREED CIDR (Pfizer Animal Health, New York, NY, USA) plus 100 µg of gonadotropin-releasing hormone (GnRH, IM; Cystorelin, Merial Ltd, Iselin, NJ, USA). On Day 7, CIDRs were removed and cows were administered 500 µg cloprostenol (IM; Estrumate, Schering-Plough Animal Health, Union, NJ, USA). Concurrently, cows were randomly allocated to receive either 80 mg FSH (FSH; n = 15; Folltropin-V, Bioniche Animal Health, Belleville, ON, Canada) or 4 mL of sterile saline (SAL; n = 16). Forty-eight h later (Day 9), cows within the FSH and SAL groups were randomly subdivided to receive either a 100-µg dose of Cysterolin (GnRH) or 3000 IU of hCG (hCG, IM; Chorulon, Intervet Inc., Millsboro, DE, USA) generating 4 treatment combinations (FSH/GnRH, n = 3; FSH/hCG, n = 7; SAL/GnRH, n = 8; and SAL/hCG, n = 8). Ovarian activity was assessed by ultrasonography to evaluate growth of the ovulatory follicle. Following CIDR removal, frequent ultrasonography was utilized to confirm ovulation (disappearance of the dominant follicle). Data were analyzed using the MIXED procedure of SAS (SAS Institute, Inc., Cary, NC, USA). Five cows from the FSH group were removed from the combination treatment due to ovulation occurring before 48 h post-CIDR removal. Size of the ovulatory follicle at time of GnRH or hCG administration was not different between FSH or SAL groups (16.7 � 0.7 v. 17.5 � 0.6 mm, respectively). Total growth of the ovulatory follicle from CIDR removal to ovulation did not differ between FSH (3.04 � 0.7 mm) and SAL (2.75 � 0.7 mm)-treated cows. As calculated from time of CIDR removal, ovulation occurred earlier in FSH (63.6 � 4.5 h) than in SAL (77.2 � 4.4 h; P < 0.05)-treated cows. Combination of FSH/GnRH produced the earliest ovulation (74 � 1.2 h) which was different only from FSH/hCG (78.6 � 0.8 h; P < 0.05), but not from SAL/GnRH or SAL/hCG (77 � 0.8 and 78 � 0.8 h, respectively). Regardless of FSH or SAL treatment, cows treated with GnRH ovulated earlier than those treated with hCG (75.5 � 0.7 v. 78.3 � 0.6 h, respectively; P < 0.05). In conclusion, while FSH was unable to increase the size of the ovulatory follicle, earlier ovulation occurred when given alone or in combination with GnRH.

Blastocyst-induced ATP release from luminal epithelial cells initiates decidualization through the P2Y2 receptor in mice

2020 ◽  
Vol 13 (646) ◽  
pp. eaba3396
Author(s):  
Xiao-Wei Gu ◽  
Zi-Cong Chen ◽  
Zhen-Shan Yang ◽  
Yan Yang ◽  
Ya-Ping Yan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Stromal Cells ◽  
Embryo Implantation ◽  
Atp Release ◽  
Sterile Inflammation ◽  
Short Exposure ◽  
Uterine Epithelial Cells ◽  
High Concentrations ◽  
Implantation Period ◽  
Luminal Epithelial Cells

Embryo implantation involves a sterile inflammatory reaction that is required for the invasion of the blastocyst into the decidua. Adenosine triphosphate (ATP) released from stressed or injured cells acts as an important signaling molecule to regulate many key physiological events, including sterile inflammation. We found that the amount of ATP in the uterine luminal fluid of mice increased during the peri-implantation period, and this depended on the presence of an embryo. We further showed that the release of ATP from receptive epithelial cells was likely stimulated by lactate released from the blastocyst through connexin hemichannels. The ATP receptor P2y2 was present on uterine epithelial cells during the preimplantation period and increased in the stromal cells during the time at which decidualization began. Pharmacological inhibition of P2y2 compromised decidualization and implantation. ATP-P2y2 signaling stimulated the phosphorylation of Stat3 in uterine luminal epithelial cells and the expression of early growth response 1 (Egr1) and prostaglandin-endoperoxide synthase 2 (Ptgs2, also known as Cox-2), all of which are required for decidualization and/or implantation, in stromal cells. Short exposure to high concentrations of ATP promoted decidualization of primary stromal cells, but longer exposures or lower ATP concentrations did not. The expression of genes encoding ATP-degrading ectonucleotidases increased in the decidua during the peri-implantation period, suggesting that they may limit the duration of the ATP signal. Together, our results indicate that the blastocyst-induced release of ATP from uterine epithelial cells during the peri-implantation period may be important for the initiation of stromal cell decidualization.

A study of returning fertility after childbirth and during lactation by measurement of urinary oestrogen and pregnanediol excretion and cervical mucus production

1985 ◽  
Vol 17 (S9) ◽  
pp. 5-23 ◽  
Author(s):  
James B. Brown ◽  
Patricia Harrisson ◽  
Margery A. Smith
Keyword(s):  
Body Temperature ◽  
Breast Feeding ◽  
Basal Body ◽  
Post Partum ◽  
Ovarian Activity ◽  
Basal Body Temperature ◽  
Cyclic Activity ◽  
Mucus Production ◽  
Unplanned Pregnancies ◽  
Number Of Cycles

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.

scholarly journals Factors influencing reproductive efficiency and pregnancy in Pura Raza Española mares

2017 ◽  
Vol 62 (No. 4) ◽  
pp. 186-191
Author(s):  
A. Akourki ◽  
A. Echegaray ◽  
MV Falceto ◽  
O. Mitjana
Keyword(s):  
Pregnancy Loss ◽  
Post Partum ◽  
Reproductive Efficiency ◽  
Ovarian Activity ◽  
Gestation Length ◽  
Ovulatory Follicle ◽  
Follicle Size ◽  
Spss Software ◽  
Twin Pregnancies ◽  
Length Of Gestation

The aim of this study was to analyse ovarian activity and pregnancy in 140 Pura Raza Espanola mares over a period of two consecutive years. The data were analysed using SPSS software to evaluate the effects of age, category of mares and season on pre-ovulatory follicle size, ovulation rate, interval from foaling to pregnancy, gestation length, incidence of twin pregnancies and pregnancy losses. The results showed that follicular diameter was significantly (P &lt; 0.05) smaller in fillies (3-year-old) and maiden mares than in older and multiparous mares. Within the group of animals treated with gonadotropin hormone hCG, 87.23% ovulated 48 h following administration. Length of gestation varied from 305 to 356 days and all gestation pregnancies of less than 305 days resulted in a non-viable foal. In addition, foaling season affected (P &lt; 0.05) the post-partum conception interval and the length of gestation, which were shorter and longer in the winter foaling, respectively. Regarding the other parameters, mares of this stud exhibited relatively very low rates of double ovulations, twin pregnancies and pregnancy losses. We conclude that age and category of mares and foaling season influence fertility and foaling rates by affecting pre-ovulatory follicle size, pregnancy loss and gestation length.

A critical role for adiponectin-mediated development of endometrial luminal epithelial cells during the peri-implantation period of pregnancy

2017 ◽  
Vol 232 (11) ◽  
pp. 3146-3157 ◽  
Author(s):  
Whasun Lim ◽  
Myung Jin Choi ◽  
Hyocheol Bae ◽  
Fuller W. Bazer ◽  
Gwonhwa Song
Keyword(s):  
Epithelial Cells ◽  
Critical Role ◽  
Implantation Period ◽  
Luminal Epithelial Cells

INDUCTION OF CYCLIC ACTIVITY IN THE EARLY POSTPARTUM DAIRY COW

1976 ◽  
Vol 56 (3) ◽  
pp. 467-473 ◽  
Author(s):  
J. G. MANNS ◽  
G. RICHARDSON
Keyword(s):  
Dairy Cows ◽  
Dairy Cow ◽  
Saline Control ◽  
Cyclic Activity ◽  
Blood Samples ◽  
Important Constraint ◽  
Lactating Dairy Cows ◽  
Early Postpartum ◽  
Prostaglandin F ◽  
Estradiol 17Β

Twenty-five lactating dairy cows were treated with either saline (control), 500 μg gonadotropin-releasing hormone (GnRH), GnRH + 10 mg estradiol 17β (E2), E2, or GnRH + E2 + 25 mg prostaglandin F2α (PGF2α) at approximately 11 days postpartum. Blood samples were taken at the time of injection and then twice each week for about 30 days. Treatment with GnRH alone gave the largest LH peak; LH production appeared to be inhibited when E2 was given with GnRH. Plasma estrogen concentrations were above 1 ng/ml for 12 h in all animals receiving estrogen alone or in combination. None of the treatments hastened initiation of cyclic activity which began at an average of 19 days postpartum. It seems unlikely that postpartum anestrus is an important constraint to early rebreeding in dairy cows.

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

1981 ◽  
Vol 32 (1) ◽  
pp. 51-54 ◽  
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.

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.

scholarly journals Influence of Male to Female Ratio on Hormone Profiles and Reproductive Performance of Anestrus Postpartum Ewes Subjected to the Male Effect

2017 ◽  
Vol 45 (1) ◽  
pp. 8
Author(s):  
José Carlos Ferreira-Silva ◽  
Tracy Anne Burnett ◽  
Paulo Francisco Maciel Póvoas Souto ◽  
Jorge Motta Rocha ◽  
Heder Nunes Ferreira ◽  
...  
Keyword(s):  
Body Condition Score ◽  
Management Practice ◽  
Blood Collection ◽  
Ovarian Activity ◽  
Female Ratio ◽  
Male Effect ◽  
Ovulatory Follicle ◽  
Conception Rates ◽  
Condition Score ◽  
Male To Female

Background: Complete isolation of genders allows intense estrous induction and synchronization once rams are introduced in ewe flocks at the onset of the breeding season (BS). This management practice, defined as the male effect, results from a neuroendocrine process mediated by pheromones. The male effect is a straightforward procedure to induce estrous in noncycling ewes, but conditions for its use have not been fully explored. Thus, this study aimed to evaluate hormone levels and ovarian activity of postpartum ewes in anestrus which are subjected to the male effect under different male to female ratios.Material, Methods & Results: Pospartum females were selected according to body condition score and cyclicity status. Females were kept apart from males during 30 days at a distance of 10 m. Anestrus and ovulation were determined by P4 measures on days 10, 20 and 30 after isolation from males. After P4 concentration diagnosis, anestrus ewe (n = 99) were subjected to male to ewe ratios (MFR) of 1:20 (MFR20), 1:30 (MFR30) and 1:40 (MFR40). Santa Inês rams  (n = 3) of proven fertility were used. Three females of each group were randomly subjected to blood collection for LH concentration analysis. Ovarian activity was performed by ultrasonography after estrus manifestation in six ewe of each group. Estrus events were observed twice a day during the BS of 35 days, and estrus were considered synchronized when it occured within the initial five days of the BS. Pregnancy diagnosis was performed by ultrasonography on days 35 and 60 after the last mating. All ewe were in a non-cycling condition before BS onset, based upon P4 analysis. After initiation of the BS, P4 concentrations increased for all groups. Irrespectively of male to female ratio, male effect induced LH pre-ovulatory peaks within the initial 26 to 86 h of the BS. Synchronization of estrus reached 50% for MFR20, 40% for MFR30 and 20% for MFR40 for all ewe. Moreover, overall estrus incidence was 100% (MFR20), 90% (MFR30) and 65% (MFR40) within the initial 15 days of the BS. However, incidence of ewe that had repeated estrus events was lower for MFR20 than for MFR30. Follicular growth and number of ovulations was similar between groups. Conception rates on first service was higher than that of second service for MFR20 and MFR30, although there was no difference between services for MFR40. In contrast, overall conception rates, delivery type and prolificacy were similar between groups.Discussion: P4 increased to cyclicity levels after contact between genders, demonstrating the potential of the male effect to induce estrus in non-cycling ewes. Most ewe ovulated within three days after the male effect, possibly due to elevated basal LH levels. Moreover, the LH preovulatory peak varied within groups, possibly due to greater interactions between genders, which ultimately may have led to earlier ovulation anticipation under lower MFR. Estrus parameters were similar between groups, suggesting low or negligible effects of MFR. Ovulatory follicle size and growth and the number of ovulations were similar between all groups; previous reports have suggested that this may be due to a strong effect of their genetic background. Conception rates were higher at first than second services, demonstrating the potential of male effect. In conclusion, male to female ratio affects the efficiency of the male effect to induce and synchronize estrus in ewes under postpartum anestrus, but it does not affect conception rates and prolificacy.

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