Reproduction in the pseudomyine rodent Mesembriomys gouldii (Gray) (Muridae)

1969 ◽  
Vol 17 (5) ◽  
pp. 785 ◽  
Author(s):  
EG Crichton
Keyword(s):  
Epithelial Cells ◽  
Litter Size ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Pregnant Female ◽  
Corpora Lutea ◽  
Limited Data ◽  
Unmated Female

M. gouldii is polyoestrous and polyovular. In the non-pregnant female the oestrous cycle is 26 � 3.5 days (range 21-35 days). Mucus appears irregularly during the dioestrous interval and seems to be derived from epithelial cells of the vagina. Ovulation is spontaneous and usually alternate, one to four corpora lutea being formed. The corpora lutea of the unmated female are functional until the 15th-17th day of the cycle. Gestation lasted from 43 to 44 days, a "placental sign" occurring between the 22nd and 33rd day. A post-partum oestrus and mating occur but no delay in implantation was recorded. Litter size ranges from one to three. The young are well developed at birth, and cling tenaciously to the teats for the first few weeks. Growth is rapid and the young can be weaned after 42 days. This pattern of reproduction is compared with the limited data from other Australian Muridae.

Oestrous cycle and gestation length in the musky rat-kangaroo, Hypsiprymnodon moschatus (Potoroidae : Marsupialia)

2001 ◽  
Vol 49 (1) ◽  
pp. 37 ◽  
Author(s):  
Shan Lloyd
Keyword(s):  
Epithelial Cells ◽  
Captive Breeding ◽  
Common Ancestor ◽  
Post Partum ◽  
Reproductive Physiology ◽  
Oestrous Cycle ◽  
Gestation Length ◽  
Vaginal Smears ◽  
Breeding Colony ◽  
Male And Female

Wild-caught male and female H. moschatus were maintained in a captive breeding colony. Vaginal smears were taken three times a week until oestrous cycles were detected and gestation lengths approximated. Thereafter, smears were usually taken daily when oestrus was expected. The gestation period (considered to be the number of days from the detection of sperm in the smear until the day young were found in the pouch) was found to last 19 days. Sperm were usually detected in the smear two days before the influx of semi-cornified and cornified epithelial cells, which occurred 17 days before parturition. A pre- or post-partum oestrus was not detected and females did not return to oestrus until at least 6 days after the removal of the last pouch young. H. moschatus has the shortest recorded gestation for any macropod, and gestation occupies approximately 75% of the oestrous cycle. The reproductive physiology of H. moschatus is similar to that of most phalangerids, which may be indicative of a common ancestor.

A note on the effect of suckling stimulus on uterine involution, post-partum ovarian activity and fertility in Nili-Ravi buffaloes

1985 ◽  
Vol 41 (1) ◽  
pp. 119-122 ◽  
Author(s):  
R. H. Usmani ◽  
N. Ullah ◽  
S. K. Shah
Keyword(s):  
Post Partum ◽  
Follicular Development ◽  
Reproductive Organs ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Limited Data ◽  
Uterine Involution ◽  
Negative Effect ◽  
The Difference ◽  
Larger Sample

ABSTRACTNineteen pluriparous buffaloes of Nili-Ravi breed which calved during the months of October and November 1983 were studied for the effects of sucking stimulus on the uterine involution, post-partum ovarian functions and fertility. On the day of calving, buffaloes were assigned to either a limited-suckling (LS) or non-suckling (NS) group. Changes in reproductive organs were monitored by rectal palpations at weekly intervals. Buffaloes were observed for oestrus twice daily (04.00 and 18.00 h) with the help of a teaser bull, and were artificially inseminated at the first post-partum and each subsequent oestrus. LS buffaloes had a shorter period to uterine involution (20 days) than NS buffaloes (28 days). Intervals to regression of the corpora lutea of pregnancy and to resumption of post-partum follicular development did not differ in the two groups. LS buffaloes had longer intervals to first post-partum oestrus and conception (54 and 88 days respectively) than NS buffaloes (39 and 68 days respectively). However, the difference in services per conception of LS and NS buffaloes was non-significant (2-05 v. 1·62). These limited data reveal that the suckling stimulus has a negative effect on the post-partum resumption of oestrous activity, and that conception is delayed. Further studies are indicated to verify these observations in a larger sample size and during all seasons of the year.

EFFECTS OF UTERINE INFUSION OF NONVIABLE SEMEN, SEMINAL PLASMA OR EGG ALBUMEN PRIOR TO BREEDING ON THE REPRODUCTIVE EFFICIENCY OF GILTS OR SOWS

1990 ◽  
Vol 70 (1) ◽  
pp. 129-133 ◽  
Author(s):  
J. R. GILES ◽  
L. H. THOMPSON ◽  
S. ARKINS ◽  
T. CAMACHO ◽  
P. A. EICHEN
Keyword(s):  
Litter Size ◽  
Seminal Plasma ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Post Partum ◽  
Pregnancy Rates ◽  
Reproductive Efficiency ◽  
Corpora Lutea ◽  
Treatment Groups ◽  
Egg Albumen

In two different experiments crossbred gilts and(or) sows were used to investigate the effects of uterine exposure (prior to breeding) to nonviable semen (NS), seminal plasma (SP) or egg albumen (EA) on reproductive performance. Treatment solutions were infused via the cervix at estrus in gilts or within 2 d post-partum in sows. Females were artificially inseminated at the subsequent estrus. In the first experiment pregnancy rates for gilts infused with Beltsville Thawing Solution (BTS) as controls, NS or EA and subsequently inseminated, were 76, 85 and 54%, respectively, and were not significantly different among treatment groups. The number of total embryos (adjusted for number of corpora lutea) present at 38 d postinsemination was 9.6, 9.0 and 9.6, respectively, for BTS, ND and EA infused gilts and was not significantly different. Likewise, the number of live and dead embryos was not different among treatments. In the second experiment, the proportions of inseminated sows infused with BTS, NS or SP that subsequently farrowed were 87, 84 and 92%, respectively, and did not differ significantly among treatments. No significant differences were detected for the number of total, live or dead pigs born per litter among treatments. We conclude that uterine exposure to seminal proteins or egg albumen prior to breeding does not alter reproductive performance in gilts by 38 d of gestation. Also, the infusion of seminal proteins in sows shortly after parturition does not affect pregnancy rates or litter size at the subsequent farrowing. Key words: Reproductive efficiency, litter size, swine, artificial insemination

scholarly journals Effect of inbreeding on ovulation rate and foetal mortality in mice

1960 ◽  
Vol 1 (3) ◽  
pp. 422-430 ◽  
Author(s):  
D. S. Falconer ◽  
R. C. Roberts
Keyword(s):  
Developmental Stage ◽  
Litter Size ◽  
Pregnant Female ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Female Mice ◽  
Inbreeding Coefficients ◽  
Foetal Mortality ◽  
Implantation Sites ◽  
Post Implantation

Dissections were made of 16-day-pregnant female mice with the object of discovering the developmental stage at which litter size is reduced by inbreeding. Counts were made of the numbers of corpora lutea, implantation sites, and live embryos, and comparisons were made between females with inbreeding coefficients of 50–60% and non-inbred females. Except in one group the embryos were all non-inbred, so that the comparisons showed the effect of inbreeding in the mother of the litter. No influence of inbreeding in the male parent was found.The only difference found between inbred and non-inbred females was in the number of eggs or embryos lost before implantation. The greater pre-implantation loss in inbred females was enough to account for the smaller number of young born alive in their litters.There was no difference between the inbred and non-inbred females in the ovulation rate, measured by the number of corpora lutea, or in the post-implantation mortality of the embryos.There was a positive correlation between ovulation rate and weight at 6 weeks. For reasons explained in the Discussion, the inbred females did not differ in weight from the non-inbred females. If, under other conditions, the weight declined on inbreeding, the ovulation rate would be expected to decline also.

Patterns of apoptosis in the corpora lutea of the rat during the oestrous cycle, pregnancy and in vitro culture

2001 ◽  
Vol 13 (3) ◽  
pp. 105 ◽  
Author(s):  
N. W. Bruce ◽  
S. Hisheh ◽  
A. M. Dharmarajan
Keyword(s):  
In Vitro Culture ◽  
Structural Changes ◽  
Molecular Mechanisms ◽  
Apoptotic Cell ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Cycle Phase ◽  
Corpora Lutea ◽  
Functional Regression

Apoptosis is associated with regression of corpora lutea (CL) in a number of species. The present work compared apoptotic rates, assessed by low molecular weight DNA labelling, in rat CL of the oestrous cycle, pregnancy, the immediate post-partum period, and in vitro culture. Apoptosis was significantly related to cycle phase with peak activity at oestrus. This pattern was similar in CL formed from the most recent ovulation and from the two previous generations. Apoptosis was evident during pregnancy, albeit at low rates. It declined on the day of parturition and increased on the following day. Apoptosis was greatly increased in cultured CL to reach 20-fold higher levels than those achieved during the oestrous cycle or pregnancy. Collectively, these results suggest that apoptosis has lesser significance in rat CL functional regression than in other species with more precipitate structural changes. However, rat CL clearly retain the potential for high rates of apoptosis and so present a useful model for examining molecular mechanisms of apoptotic cell death.

Reproduction of Pseudomys novaehollandiae (Muridae) in the laboratory

1976 ◽  
Vol 24 (2) ◽  
pp. 159 ◽  
Author(s):  
CM Kemper
Keyword(s):  
Litter Size ◽  
Sexual Maturity ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Day Length ◽  
Dark Phase ◽  
Weight Changes ◽  
External Appearance ◽  
Average Litter Size ◽  
Lactating Females

Oestrous cycle, gestation, parturition, litter size, lactation and sexual maturity were studied in a captive colony of the Australian murid P. novaehollandiae. The pattern of reproduction is similar to that of other murids, although oestrous cycle (6.0 � 1.26 days) and gestation period (31.5 � 0.96 days) are longer than those in the laboratory rat and mouse. Changes in the external appearance of the vagina were too inconsistent to identify stages of the oestrous cycle, but were of use in determining the stage of pregnancy or lactation. Parturition took place during the light phase of the day-length regime, with post-partum oestrus during the following dark phase. Weight changes in pregnant and lactating females were considered. The average litter size was 4.0 � 1.03 with a range of one to six. Oestrus was inhibited during lactation and recurred about 24 days after parturition. Sexual maturity was earlier in females (13 weeks) than in males (20 weeks).

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.

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.

Aspects of reproduction in the genus Notomys (Muridae)

1974 ◽  
Vol 22 (4) ◽  
pp. 439 ◽  
Author(s):  
EG Crichton
Keyword(s):  
Reproductive Biology ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Interspecific Variations

Reproductive biology was studied in captive N. alexis, N. fuscus, N. mitchellii and N, cervinus. All were polyoestrous, the oestrous cycle averaging 7.0-8.0 days in N. alexis and N. mitchellii and 9.0 days in N. fuscus. In N. cervinus there was a considerable variation in length; this species may be easily stressed and less adaptable to captivity. Gestation in the non-lactating animal lasted 32, 34-37 and 38-43 days in N. alexis, N. mitchellii and N, cervinus respectively; all three had post-partum oestrus and mating. Lactation appeared to delay implantation in N, cervinus and probably in N. mitchellii, but not in N. alexis; it lasted 3-4 weeks, during which time the young clung tenaciously to the teats. Oestrus was not always suspended during lactation in N. alexis, and conception may take place during suckling in this species. Interspecific variations in this pattern of reproduction are discussed, and the information compared with data from other Australian Muridae.

Reproductive Ecology of The Allied Rock-wallaby, Petrogale assimilis.

1996 ◽  
Vol 19 (2) ◽  
pp. 209
Author(s):  
R. Delaney
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Sexual Maturity ◽  
Post Partum ◽  
Reproductive Ecology ◽  
Oestrous Cycle ◽  
Embryonic Diapause ◽  
Minimum Age

Petrogale assimilis has a typical life history and reproductive ecology for a macropodid of its size. Both sexes are capable of reproducing continuously; gestation is about the same length as the oestrous cycle (approximately one month); a single young is born and, a post-partum oestrus and embryonic diapause probably occurs. The sex ratio of young is unbiased. Pouch young remain permanently attached to the teat until 110 - 143 days (n=11). Permanent exit from the pouch occurs at 180 - 231 days (mean=201 days, n=25), and weaning occurs between 267 - 387 days (n=5). Sexual maturity occurs at a minimum age of 17.5 months in females and 23 months in males.

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