The Reproductive Rate of the Hopping-Mouse Notomys Alexis and Its Ecological Significance.

1979 ◽  
Vol 27 (2) ◽  
pp. 177 ◽  
Author(s):  
WG Breed
Keyword(s):  
Post Partum ◽  
Cumulus Cells ◽  
Reproductive Rate ◽  
Seminiferous Tubules ◽  
Corpora Lutea ◽  
Fallopian Tubes ◽  
Ecological Significance ◽  
High Population Density ◽  
Young Females ◽  
Pregnant Females

In the male hopping-mouse, spermatozoa first appeared in seminiferous tubules on day 60 and were present in the epididymis a few days later; ventral prostates markedly increased in weight between days 56 and 60. Some females had large Graafian follicles, stimulated uteri and perforate vaginae on day 40; corpora lutea were first observed on day 44, but most females did not spontaneously ovulate until after day 54. Gestation in post-partum mated, non-suckling females lasted about 32 days, with implantation on day 7 or 8. When four or more young were suckling, gestation increased to 39 days (mean); implantation took place between days 11-13 and 14-17 when there were either three or four, or five, suckling young respectively. From one to three unfertilized oocytes surrounded by cumulus cells were found in the Fallopian tubes between days 7 and 17 in some pregnant females. Post partum, the most common ovulation rate and litter size was 4; 72% of these litters fully survived to weaning; 10-15% of litters were of five or six young and nearly half of these fully survived to weaning; in the natural environment litters were of four or five young. Without post-partum mating and without suckling young, females had ovulated spontaneously by days 9-11. Significantly fewer females suckling from four to six young had oocytes at this time, but the percentage had increased by days 15-18. This indicates a delay, but not prevention, of spontaneous ovulation during lactation. Field-caught females from the southern Northern Territory were reproductively inactive on three out of four occasions. The fourth time, when there had been > 50 mm of rain in the preceding few weeks, all adult females caught had corpora lutea and some were pregnant. Greatest ovarian inhibition coincided with high population density. When compared to data for small northern temperate-zone rodents, most of the above reproductive parameters do not indicate a high reproductive rate, but data for closely related, apparently non-cyclic, Australian species appear to be similar except for, possibly, age of puberty and spontaneous ovulation during lactation. The significance of these results to r-strategy in this species is discussed.

Pregnancy in the lactating pigmy possum, Cercartetus concinnus

1967 ◽  
Vol 15 (4) ◽  
pp. 673 ◽  
Author(s):  
MJ Clarke
Keyword(s):  
Connective Tissue ◽  
Post Partum ◽  
Circumstantial Evidence ◽  
Corpora Lutea ◽  
Embryonic Diapause ◽  
Luteal Regression ◽  
Pregnant Females ◽  
Pass Through

The reproductive tracts of seven Cercartetus concinnus with pouch young were examined. One female had recently given birth, four were pregnant, and two were in anoestrus. The post-partum female was near oestrus. The ovaries contained corpora lutea and large follicles, and luteal regression was occurring in the uteri. Ovaries of pregnant females contained old corpora lutea and corpora lutea of pregnancy. Blastocysts recovered from the uteri increased in size with age of the pouch young. Corpora lutea of pregnancy out-numbered blastocysts in many females, and blastocysts often out-numbered teats. Ovaries of anoestrous females contained only old corpora lutea. During birth the young pass through a cleft in the connective tissue between the posterior end of the vaginal culs-de-sac and the posterior vaginal sinus. This cleft, the pseudovaginal canal, closes after parturition. The observation that embryos of C. concinnus do not enter diapause contrasts with conclusions previously drawn from circumstantial evidence that the pigmy possum resembled several species of Macropodidae in undergoing embryonic diapause.

Histological Changes in the Ovary of the Hopping-Mouse Notomys Alexis During Lactation.

1977 ◽  
Vol 25 (3) ◽  
pp. 401 ◽  
Author(s):  
WG Breed
Keyword(s):  
Post Partum ◽  
Histological Structure ◽  
Corpora Lutea ◽  
Fallopian Tubes ◽  
Histological Changes ◽  
Follicular Size

The histological structure of the ovary of the lactating hopping-mouse is described. Two sets of corpora lutea are usually present, one of which appears to degenerate fairly rapidly during lactation and is thus considered to be the corpora lutea of pregnancy. Spontaneous ovulation usually occurs after parturition; thus corpora lutea of lactation are formed which appear to remain healthy-looking throughout most of lactation. Oocytes were flushed from Fallopian tubes immediately after parturition, but then not again until at least day 10 of lactation. Vesicular follicles were not present after post-partum ovulation, but had usually developed by day 5. In females suckling three or more young, however, maximum follicular size did appear to be somewhat inhibited, compared to that in females suckling one young, from days 5 to 11 of lactation; by day 15 larger vesicular follicles had developed and recently formed corpora lutea were present in one individual.

Breeding of a Captive Colony of Notomys fuscus Wood Jones (Rodentia : Muridae)

1980 ◽  
Vol 7 (3) ◽  
pp. 379 ◽  
Author(s):  
HJ Aslin ◽  
CHS Watts
Keyword(s):  
Breeding Season ◽  
Vaginal Bleeding ◽  
Post Partum ◽  
Reproductive Rate ◽  
Oestrous Cycle ◽  
Gestation Period ◽  
Pregnant Females ◽  
Delayed Implantation ◽  
Lactating Females

Reproductive data were obtained from a captive colony of N. fuscus over 10 years. Females had an oestrous cycle averaging 7.4 days, and a gestation period averaging 34.3 days. Only three possible instances of post-partum mating were recorded, but. some lactating females returned to oestrus 14-22 days after birth of their young. There was no evidence of delayed implantation due to lactation. Vaginal bleeding occurred in pregnant females 8-17 days before birth. Seventy-four litters were born, litter sizes ranging from one to five, average 2.7. No breeding season was evident. Both sexes were reproductively mature at 70 days old. Comparisons are made with other species of Notomys, and their generally low reproductive rate discussed.

HEMMUNG VON TESTOSTERONABHÄNGIGEN DIFFERENZIERUNGSVORGÄNGEN DER MÄNNLICHEN RATTE NACH DER GEBURT

1967 ◽  
Vol 54 (2) ◽  
pp. 227-240 ◽  
Author(s):  
F. Neumann ◽  
J. D. Hahn ◽  
M. Kramer
Keyword(s):  
Sexual Behaviour ◽  
Cyproterone Acetate ◽  
Post Partum ◽  
Sexual Attitude ◽  
Normal Male ◽  
Corpora Lutea ◽  
List Type ◽  
Newborn Rats ◽  
Neonatal Treatment ◽  
Triangular Shape

ABSTRACT Male newborn rats were injected with 2 mg of an antiandrogen (1,2α-methylene-6-chloro-pregna-4,6-dien-17α-ol-3,20-dione-17α-acetate = cyproterone acetate) daily from their 1st to their 14th day of life. The following effects of this treatment were observed in these animals after onset of sexual maturity: 84% of the animals are unable to reproduce. Penis: the frenulum is broadened to a lamina of triangular shape, which almost completely prevents the preputium from being pushed back. These males show a rather insufficient male sexual behaviour towards females in oestrus. After castration and ovar implantation, some of the treated animals show true corpora lutea and at attempts of cohabitation partially female sexual behaviour towards normal male animals. From these results it can be concluded, that differentiation of the penis is not completed at the time of birth. The infertility of the animals may be caused by the penile changes (difficulties with intromission) as well as by the aimless sexual behaviour. This aimless sexual behaviour, the ability to produce true corpora lutea and finally their partially female sexual attitude under the influence of the hormones from the implanted ovaries led to the conclusion, that the above described neonatal treatment apparently inhibited testosterone-depending post partum developments of sexual differentiation in hypothalamic centers.

Localization of oxytocin and neurophysin in baboon (Papio anubis) corpus luteum by immunocytochemistry

1986 ◽  
Vol 113 (4) ◽  
pp. 570-575 ◽  
Author(s):  
Firyal S. Khan-Dawood
Keyword(s):  
Corpus Luteum ◽  
Rabbit Serum ◽  
Corpora Lutea ◽  
Positive Staining ◽  
Normal Rabbit Serum ◽  
Fallopian Tubes ◽  
Papio Anubis ◽  
Luteal Cells ◽  
Luteal Tissue ◽  
Immunocytochemical Reaction

Abstract. Immunoreactive oxytocin is detectable in the corpora lutea of women and cynomolgus monkeys by radioimmunoassay. To localize the presence of oxytocin and neurophysin I in ovarian tissues of subhuman primates, three corpora lutea and ovarian stromal tissues and two Fallopian tubes obtained during the menstrual cycle of the baboon and decidua from two pregnant baboons were examined using highly specific antisera against either oxytocin or neurophysin I and preoxidase-antiperoxidase light microscopy immunohistochemistry. Oxytocin-like as well as neurophysin I-like immunoreactivities were found in some cells of all the corpora lutea only, but could not be demonstrated in ovarian stromal tissues, Fallopian tubes and decidua. Specificity of the immunocytochemical reaction was further confirmed by immunoabsorption of the antiserum with excess oxytocin or neurophysin, after which the immunoreactivities for both oxytocin and neurophysin in the luteal tissue were negative. Similar controls using normal rabbit serum gave no positive staining for either oxytocin or neurophysin. Counterstaining of the positive immunoreactivities for oxytocin and neurophysin I with Mayer's haematoxylin and eosin demonstrated clearly that the oxytocin and neurophysin I appeared as granular material mainly within the cytoplasm of the luteal cells. The localization of immunoreactive oxytocin and neurophysin I in the corpus luteum of the baboon demonstrates directly the presence of these two neurohypophysial peptides within primate luteal cells and suggests their local production.

Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus)

Reproduction ◽  
2000 ◽  
pp. 49-57 ◽  
Author(s):  
SD Johnston ◽  
MR McGowan ◽  
P O'Callaghan ◽  
R Cox ◽  
V Nicolson
Keyword(s):  
Luteal Phase ◽  
Post Partum ◽  
Plasma Concentrations ◽  
External Genitalia ◽  
Oestrous Cycle ◽  
Phascolarctos Cinereus ◽  
Pregnant Females ◽  
Peripheral Plasma ◽  
The Mean ◽  
High Concentrations

As an integral part of the development of an artificial insemination programme in the captive koala, female reproductive physiology and behaviour were studied. The oestrous cycle in non-mated and mated koalas was characterized by means of behavioural oestrus, morphology of external genitalia and changes in the peripheral plasma concentrations of oestradiol and progestogen. The mean (+/- SEM) duration of the non-mated oestrous cycle and duration of oestrus in 12 koalas was 32.9 +/- 1.1 (n = 22) and 10.3 +/- 0.9 (n = 24) days, respectively. Although the commencement of oestrous behaviour was associated with increasing or high concentrations of oestradiol, there were no consistent changes in the morphology or appearance of the clitoris, pericloacal region, pouch or mammary teats that could be used to characterize the non-mated cycle. As progestogen concentrations remained at basal values throughout the interoestrous period, non-mated cycles were considered non-luteal and presumed anovulatory. After mating of the 12 koalas, six females gave birth with a mean (+/- SEM) gestation of 34.8 +/- 0.3 days, whereas the remaining six non-parturient females returned to oestrus 49.5 +/- 1. 0 days later. After mating, oestrous behaviour ceased and the progestogen profile showed a significant increase in both pregnant and non-parturient females, indicating that a luteal phase had been induced by the physical act of mating. Progestogen concentrations throughout the luteal phase of the pregnant females were significantly higher than those of non-parturient females. Parturition was associated with a decreasing concentration of progestogen, which was increased above that of basal concentrations until 7 days post partum.

Reproductive function in average and high yielding dairy cows

2001 ◽  
Vol 26 (2) ◽  
pp. 495-498 ◽  
Author(s):  
Victoria J. Taylor ◽  
Andrew J. Hattan ◽  
Emma C.L. Bleach ◽  
David E. Beever ◽  
D. Claire Wathes
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Post Partum ◽  
Reproductive Function ◽  
Reproductive Activity ◽  
Corpora Lutea ◽  
Genetic Merit ◽  
Standard Management ◽  
Service Conception ◽  
The Difference

AbstractThe resumption of reproductive activity in the early post partum period and the subsequent fertility of dairy cows are of considerable practical and economic importance to the producer. Regular milk progesterone analysis was used in this study to monitor the re-establishment of reproductive cyclicity in animals of average (AGM, n=20) and high genetic merit (HGM, n=28) kept under standard management conditions. The profiles obtained were then characterised into normal and four different types of abnormal activity. Resumption of cycles occurred significantly later in the higher yielding cows than in those of average genetic merit (23 ±2.3 days in HGM cows and 15 ± 1.6 days in AGM cows; P=0.0089). There was a significant increase in the amount of abnormal cycles encountered in the high genetic merit animals compared with average yielding animals (61% and 30% respectively; χ2 test, P=0.045); in particular, the delayed occurrence of ovulation post partum (11% vs 0%) and an increased incidence of persistent corpora lutea (32% vs 20%). For high genetic merit animals, the incidence of abnormal cycles was associated with increased peak milkyields (abnormal cycles: peak milk yield 54.7 ± 1.11 kg/day; normal cycles: peak milk yield 46.4 ± 1.35 kg/day, P=0.002). This relationship was not apparent in average genetic merit animals. First service conception rates were 50% (9/18) for AGM cows and 38% (10/26) for HGM cows (χ2 test, n.s.). The calving to conception interval was 98 ± 9.7 days for AGM animals (n=l7) and 105 ± 9.1 days for HGMs (n=24) (t-test, n.s.). In conclusion, this study confirms that high genetic merit dairy cows have compromised reproductive function in terms of a delayed resumption of cyclicity and an increased incidence of abnormal progesterone cycles, which was associated with higher peak milk yields. There was also a reduced first service conception rate in high yielders although the difference was not significant with this group size.

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.

EFFECTS OF PROSTAGLANDIN F2α ON SOME REPRODUCTIVE PROCESSES OF HAMSTERS AND RATS

1972 ◽  
Vol 53 (2) ◽  
pp. 201-213 ◽  
Author(s):  
A. P. LABHSETWAR
Keyword(s):  
Prostaglandin F2α ◽  
Concomitant Administration ◽  
Corpora Lutea ◽  
Fallopian Tubes ◽  
Racemic Form ◽  
Endocrine Profile ◽  
Prostaglandin F ◽  
Blue Reaction ◽  
Egg Transport ◽  
Reproductive Processes

SUMMARY In an attempt to characterize the endocrine profile of prostaglandin F2α (PGF2α) in relation to the female reproductive system, the compound (racemic form) was administered to hamsters and rats in various reproductive states. The prostaglandin terminated pregnancy when given once a day either subcutaneously (50 μg/hamster) or orally (1·5–2 mg/hamster) from Days 4 to 6 of pregnancy inclusive, or as a single subcutaneous injection (50 μg/animal) on Day 4. In the rat, higher (500 μg/injection) and more frequent (twice daily) s.c. injections were required to get even foetal resorption. Concomitant administration of progesterone (4 mg/animal) in either species protected pregnancy. Prostaglandin F2α terminated pregnancy without interfering with the Pontamine blue reaction, suggesting that its antifertility effects were not mediated by inhibition of implantation. In both hamsters and rats the prostaglandin markedly reduced the size of deciduomata which could be restored to normal by administration of progesterone. Prostaglandin F2α delayed passage of zygotes through the Fallopian tubes in a proportion of rats but failed to accelerate egg transport in rats and hamsters. Furthermore, it caused a marked histological degeneration of the corpora lutea and induced formation of a fresh set of corpora lutea in pseudopregnant, pregnant and pseudopregnant—hysterectomized hamsters. These deleterious effects of prostaglandin were accompanied, in hamsters, by the appearance of freshly ovulated tubal ova. Most of the endocrine effects of PGF2α observed in this study can be accounted for by its luteolytic property.

Sign in / Sign up

Export Citation Format

Share Document