Reproduction in a laboratory colony of the marsupial mouse Sminthopsis larapinta (Mardupialia : Dasyuridae)

1969 ◽  
Vol 17 (4) ◽  
pp. 637 ◽  
Author(s):  
GK Godfrey
Keyword(s):  
Breeding Season ◽  
Maximum Size ◽  
Urogenital Sinus ◽  
Corpora Lutea ◽  
Young Females ◽  
The Third ◽  
Laboratory Colony ◽  
The Mean ◽  
Mean Cycle ◽  
North Western

A laboratory colony of S. larapinta was established with three females and four males received from north-western Queensland. Over a period of two and a half years 109 young were born and second-generation descendants were produced. In the third breeding season oestrous cycles were irregular and, in the few instances where copulation was recorded, this was associated with almost 100% prenatal mortality. The colony became extinct without the cause being definitely established. In Adelaide S. larapinta had a well-defined breeding season with all females either pregnant or in oestrus from July to February. From March until June all the females were in anoestrus. The males produced sperm throughout the year. A technique was developed for determining the length of the oestrous cycle, based upon the incidence of epithelial cells in the urine. S. larapinta is polyoestrous, with a mean cycle length of 26.25�0.5 days. Gestation occupies 12.5 days, and a maximum of eight young remain in the pouch, attached to the teats, for 40 days. They are suckled in the nest for a further 30 days. Weaning takes place at 70 days, and the young females come into oestrus from 4 months of age onwards. Twenty female reproductive tracts were sectioned and examined and the anatomy and histology described briefly. The mean number of ova shed per ovulation was 30.6 (n = 12) with one instance of 40. The corpora lutea are formed rapidly, and reach their maximum size towards the end of pregnancy. They have completely regressed by the seventh week of lactation. The young are born through a pseudovaginal canal which extends from the median vagina to the urogenital sinus. This closes within 24-48 hr of parturition. The high "pre-pouch" and litter mortality observed during this study is discussed.

Reproduction in Sminthopsis-Macroura (Marsupialia, Dasyuridae) .1. The Female

1990 ◽  
Vol 38 (2) ◽  
pp. 187 ◽  
Author(s):  
PA Woolley
Keyword(s):  
Body Weight ◽  
Reproductive Tract ◽  
Corpora Lutea ◽  
Laboratory Colony ◽  
Histological Appearance ◽  
Lactating Females ◽  
Sminthopsis Macroura ◽  
The Mean ◽  
Mean Cycle ◽  
Breeding Seasons

A laboratory colony of S. macroura, founded by three females and four males, was maintained over four breeding seasons. Reproductive success was high and four generations were produced before the colony was disbanded. Descendants of these animals are still breeding in another laboratory 11 years after the founding of the colony. A detailed prescription for the maintenance and management of a breeding colony is given. The animals bred between June and February, most females first entering oestrus in the early months of the season, in July or August. Female young born early in the season (before mid-October) matured in the season of their birth at an age of 86-159 days; those born later matured in the following season at an age of 185-262 days. In each group, those born later matured earlier. Minimum body weight at sexual maturity was 12.5 g. At least two litters can be reared in a season and individuals may breed in more than one season. S. macroura is polyoestrous with a mean cycle length of 23.25 days. The gestation period is about 11 days and up to eight young can be accommodated in the pouch. Lactating females may return to oesrrus up to 10 days before the young are weaned at 70 days old. Ovulation occurs spontaneously and the mean number of corpora lutea formed was 20.7. The corpora lutea reach maximal size late in pregnancy and they regress more rapidly in lactating than in non- lactating females. Up to three generations of corpora lutea could be recognised in the ovaries of females undergoing cycles uninterrupted by lactation. Changes In body weight, the pouch, and the gross and histological appearance of the reproductive tract were the same in pregnant and pseudopregnant females.

Comparison of plasma progesterone profiles in cyclic, pregnant, pseudopregnant and hysterectomized pigs between 8 and 27 days after oestrus

1988 ◽  
Vol 119 (1) ◽  
pp. 111-116 ◽  
Author(s):  
G. J. King ◽  
R. Rajamahendran
Keyword(s):  
Least Squares ◽  
Analysis Of Variance ◽  
The Other ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
The Third ◽  
Secretory Potential ◽  
The Mean

ABSTRACT Plasma progesterone concentrations were compared in cyclic (n = 12), pregnant (n =12), oestradiol-induced pseudopregnant (n=12) and hysterectomized gilts (n=10) between days 8 and 27 after oestrus. The results were grouped into periods covering days 8–13, 14–20 and 21–27 and analysed by least-squares analysis of variance. Plasma progesterone concentrations were significantly (P<0·001) higher in hysterectomized compared with other groups between days 8 and 13. Progesterone concentrations declined rapidly after day 14 in cyclic females and gradually in the other groups. Throughout the third and fourth weeks the mean progesterone concentrations for hysterectomized animals were consistently higher than for pseudopregnant animals (P<0·05). The pregnant group means were below but not significantly different from the hysterectomized means in both of the last two periods. The greater progesterone concentrations in hysterectomized gilts indicated that secretion is high without any conceptus-produced or -mediated luteotrophin, and corpora lutea in cyclic, pregnant or pseudopregnant gilts may never reach full secretory potential. J. Endocr. (1988) 119, 111–116

Observations on the onset of the breeding season and on the oestrous cycle of the Welsh Mountain ewe

1964 ◽  
Vol 63 (1) ◽  
pp. 59-60 ◽  
Author(s):  
J. S. M. Hutchinson ◽  
P. J. O'Connor ◽  
H. A. Robertson
Keyword(s):  
Breeding Season ◽  
Cycle Length ◽  
Oestrous Cycle ◽  
The Mean ◽  
Mean Cycle

1.Within a flock of 55 Welsh Mountain ewes maintained under lowland conditions the first ewe came into oestrus on the 14th October. The mean cycle length of 44 normal cycles was 16 days 3 hr.2. The onset of oestrus as assessed by the time of mounting of the ram does not appear to be evenly distributed throughout the day (24 hr.).

scholarly journals Effects of environmental factors on multiple ovulation of zebu donors

2006 ◽  
Vol 58 (4) ◽  
pp. 567-574 ◽  
Author(s):  
M.G.C.D. Peixoto ◽  
J.A.G. Bergmann ◽  
C.G. Fonseca ◽  
V.M. Penna ◽  
C.S. Pereira
Keyword(s):  
Environmental Factors ◽  
Least Squares ◽  
Inbreeding Coefficient ◽  
Corpora Lutea ◽  
Data Sets ◽  
Data Set ◽  
The Third ◽  
Multiple Ovulation ◽  
The Mean ◽  
Best Responses

Data on 1,294 superovulations of Brahman, Gyr, Guzerat and Nellore females were used to evaluate the effects of: breed; herd; year of birth; inbreeding coefficient and age at superovulation of the donor; month, season and year of superovulation; hormone source and dose; and the number of previous treatments on the superovulation results. Four data sets were considered to study the influence of donors’ elimination effect after each consecutive superovulation. Each one contained only records of the first, or of the two firsts, or three firsts or all superovulations. The average number of palpated corpora lutea per superovulation varied from 8.6 to 12.6. The total number of recovered structures and viable embryos ranged from 4.1 to 7.3 and from 7.3 to 13.8, respectively. Least squares means of the number of viable embryos at first superovulation were 7.8 ± 6.6 (Brahman), 3.7 ± 4.5 (Gyr), 6.1 ± 5.9 (Guzerat) and 5.2 ± 5.9 (Nellore). The numbers of viable embryos of the second and the third superovulations were not different from those of the first superovulation. The mean intervals between first and second superovulations were 91.8 days for Brahman, 101.8 days for Gyr, 93.1 days for Guzerat and 111.3 days for Nellore donors. Intervals between the second and the third superovulations were 134.3, 110.3, 116.4 and 108.5 days for Brahman, Gyr, Guzerat and Nellore donors, respectively. Effects of herd nested within breed and dose nested within hormone affected all traits. For some data sets, the effects of month and order of superovulation on three traits were importants. The maximum number of viable embryos was observed for 7-8 year-old donors. The best responses for corpora lutea and recovered structures were observed for 4-5 year-old donors. Inbreeding coefficient was positively associated to the number of recovered structures when data set on all superovulations was considered.

Annual reproductive rhythm and ovulation rate in four fat-tailed sheep breeds

1978 ◽  
Vol 26 (2) ◽  
pp. 177-184 ◽  
Author(s):  
N. Sefidbakht ◽  
M. S. Mostafavi ◽  
A. Farid
Keyword(s):  
Sexual Activity ◽  
Seasonal Pattern ◽  
Recovery Phase ◽  
Significant Decline ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Sexually Active ◽  
Monthly Variation ◽  
The Mean ◽  
Mean Cycle

ABSTRACTKarakul, Mehraban, Naeini and Bakhtiari sheep were checked twice a day for oestrus using aproned rams and were laparotomized within 5 to 16 h of the end of every second oestrous period. Oestrus was observed for 12 monthly periods commencing on 21 April.The Mehraban breed with 1 -6 oestrous periods per month was less seasonal in its breeding activity (P<0·01) than the other breeds. Four-year-old ewes were more sexually active (P<0·01) than 3-year-old ewes (1·48 v. 1·28 oestrous periods per month). Seasonal variation in the sexual activity of the ewes was observed (P<001); the peak of activity in July to January was followed by a steady decline in February and March to a low in April and May, and then a steep recovery phase in June. There was only limited sexual activity for at least 4 months (March to June).The overall mean cycle length was 17·8 days (14 to 23 days), and the means for the four breeds were 17·6, 17·8, 17·8 and 17·9. The oestrous cycle was longer (P<0·05) during the period from December t o February than during that from June to August.The overall mean duration of the oestrous period was 36·9 h and the means for the four breeds were 35·2, 38·0, 37·4 and 37·1 h, respectively (P<0·05). The duration showed some monthly variation (P<0·01) but did not follow a special seasonal pattern. The ovulation rates for the four breeds were 1·07, 1·13,0·94 and 0·95 respectively, (P<0·01). There was a non-significant decline in the mean ovulation rate from March to June. Right ovaries were more active than left ovaries as judged by the observation of a higher average number of corpora lutea per ewe per laparotomy (0·58 v. 0·43, P<001).

Reproduction in the Female Dasyurid Antechinus-Minimus-Maritimus (Marsupialia, Dasyuridae)

1986 ◽  
Vol 34 (2) ◽  
pp. 189 ◽  
Author(s):  
BA Wilson
Keyword(s):  
Epithelial Cells ◽  
Breeding Season ◽  
Field Data ◽  
Corpora Lutea ◽  
Mark Recapture ◽  
Laboratory Colony ◽  
Pattern Length ◽  
Young Breeding ◽  
Length Of Gestation

Reproduction in female Antechinus minimus maritimus was investigated in the field and laboratory. Field data were obtained from a mark-recapture study. A laboratory colony was maintained to investigate the oestrous pattern, length of gestation and development of pouch young. Breeding occurred in winter with births in July or August. Gestation (mean � SD) was 30.6 � l.5 days for animals mated in the laboratory. Epithelial cells were present in the urine for 34.8 � 8.3 days, a lengthy period compared to A. stuartii (19.3 � 4.4 days). Ovaries from females before the breeding season contained small developing follicles. During the breeding season Graafian follicles (4-8 per ovary) or corpora lutea (4-13 per ovary) were found. Reproduction in A. m. maritimus females is similar to that described previously in other Antechinus.

The evolution of sexual dimorphism in the skink Eumeces laticeps: an example of sexual selection

1985 ◽  
Vol 63 (5) ◽  
pp. 995-1002 ◽  
Author(s):  
Laurie J. Vitt ◽  
William E. Cooper Jr.
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Breeding Season ◽  
Prey Size ◽  
Maximum Size ◽  
Head Size ◽  
Sexually Dimorphic ◽  
Eumeces Laticeps ◽  
Aggressive Male ◽  
The Mean

Adults of the skink Eumeces laticeps are sexually dimorphic in coloration, body size, head size, and relative head size. Males have larger heads at a given body size than females and the divergence in relative head size is coincident with the size at which sexual maturity is reached. Although there were no differences between sexes in tail loss frequencies, there were substantial differences in frequencies of body and head scars, a consequence of aggressive male–male interactions. Prey size was correlated with body and head size and males tended to eat larger prey items than females. However, both sexes are capable of eating prey much larger than the mean or maximum size of prey found in stomachs, suggesting that resource partitioning is a consequence of sexual size differences rather than a cause. The heads of males at a given body size increase during the breeding season, and a combination of head and body size apparently determines the outcome of intrasexual aggressive encounters. Moreover, small males were never observed with females during the breeding season, and those males observed "guarding" females were significantly larger than males observed in the absence of females. We conclude that sexual selection accounts for many of the differences in morphological traits between sexes of E. laticeps.

OVULATION AND CORPUS LUTEUM FUNCTION IN THE LLAMA (LAMA GLAMA)

1969 ◽  
Vol 45 (4) ◽  
pp. 505-513 ◽  
Author(s):  
B. G. ENGLAND ◽  
W. C. FOOTE ◽  
D. H. MATTHEWS ◽  
ARMANDO G. CARDOZO ◽  
S. RIERA
Keyword(s):  
Luteinizing Hormone ◽  
Corpus Luteum ◽  
Breeding Season ◽  
Luteal Phase ◽  
Maximum Size ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Corpora Lutea ◽  
Lama Glama

SUMMARY Results in 53 llamas (33 mated animals and 20 controls) showed that ovulation is copulation-induced in this species. Ovulation without copulation occasionally occurred during the height of the recognized breeding season in Bolivia. The first mating during the luteal phase (12–24 days after the preceding ovulation) resulted in ovulation in four out of ten llamas. Determination of pituitary luteinizing hormone (LH) content showed the highest level on the day before mating (9·00 μg./mg.) and the lowest level on day 4 (6·25 μg./mg.). LH level on day 8 was significantly higher than on day 4 (7·62 μg./mg.). Corpora lutea (c.l.) were well formed on day 4 after mating (408 mg.), reached a maximum size by day 8 (1920 mg.) and rapidly decreased in size to day 16 (136 mg.). The corpus albicans remained as an entity but decreased in size to 21 mg. on day 120. Similar changes were found in c.l. histology and progesterone content. The combined results indicate that the functional life of the c.l. in a non-pregnant llama is 16 days or less. Treatment with 25 i.u. human chorionic gonadotrophin was sufficient to cause ovulation in 50% of the animals treated. A large (150 mg.) dose of norethandrolone did not cause morphological regression of the c.l. when measured 5 days after treatment. Treatment with 5 mg. daily for 14 days caused regression of c.l. as compared with untreated controls and animals treated with oestradiol valerate.

76 Effect of season on the superstimulation response, embryo quality, and pregnancy establishment in dromedary camel (Camelus dromedarius)

2021 ◽  
Vol 33 (2) ◽  
pp. 146
Author(s):  
H. A. Abouhefnawy ◽  
N. A. Wani
Keyword(s):  
Breeding Season ◽  
Embryo Quality ◽  
Treatment Protocol ◽  
Uterine Horn ◽  
Dromedary Camel ◽  
Corpora Lutea ◽  
Dromedary Camels ◽  
Nonbreeding Season ◽  
Single Intramuscular Injection ◽  
The Mean

The present study was conducted to study the effect of season on the superstimulation response, embryo quality and pregnancy establishment in the dromedary camels. Two donors each were superstimulated in the month of June 2019 (non-breeding season) and January 2019 (breeding season) by a combination of 2500IU of equine chorionic gonadotrophin (eCG, Folligon; Intervet), given as a single intramuscular injection on Day 1 of the treatment protocol, and 400mg of pFSH (Folltropin; Bioniche) injected twice daily in declining doses of 2×80mg, 2×60mg, 2×40mg, and 2×20mg over 4 days, also beginning on Day 1. They were scanned by rectal ultrasonography and follicles counted before mating with a fertile bull on Day 11 after the start of treatment. An injection of 20µg of gonadotrophhin-releasing hormone (Receptal, Intervet) was given immediately after mating to induce ovulation. The number of corpora lutea (CL) were counted, and the embryos collected by the non-surgical method on Day 7 after ovulation. All embryos were washed and graded before they were transferred individually into the left uterine horn of recipient animals, synchronized to be on Day 6 after ovulation. All recipients were screened by ultrasonography on Day 22, Day 60, and Day 90 for pregnancies. The data were analysed using a two-sample t-test (Minitab statistical software, Minitab Ltd.). No difference was observed in the mean number of follicles developed (20.5 vs. 18.5) between the donors in breeding and non-breeding season, respectively. The percent mean±s.e.m. of ovulations as observed by counting the CL in nonbreeding season (80.7±3.4) were not different from those in breeding season (85.4±3.7). A total number of 16 embryos collected during non-breeding season and 20 embryos in breeding season were transferred to recipients. The percent mean±s.e.m. of pregnancies established on Day 22 (56.6±3.4 vs. 67.5±7.5) and on Day 90 (47.2±2.8 vs. 60±0.0) were similar in both groups. These observations indicate that embryo transfer technology can be applied to camels during the summer months, which is considered the non-breeding season, and pregnancies can be established at par with breeding season. In conclusion, to the best of our knowledge, this is the first study in camels wherein we have demonstrated that donor camels can be superstimulated, embryos can be collected, recipient animals can be synchronized, and pregnancies can be established in the summer (non-breeding) months. The embryos collected from elite donors can be transferred to synchronized recipients to establish pregnancies or preserved for future use. Some owners do not want calves to be born in summer months, so protocols need to be established for storing these embryos for a few months before their transfer to recipients, to have the calves delivered in the desired winter months.

Observations on the corpus luteum during pregnancy and lactation in the marsupials Isooson macrous and Perameles nasuta

1979 ◽  
Vol 27 (5) ◽  
pp. 881 ◽  
Author(s):  
AG Lyne ◽  
DE Hollis
Keyword(s):  
Connective Tissue ◽  
Maximum Size ◽  
Corpora Lutea ◽  
Lactation Period ◽  
Tissue Component ◽  
Luteal Cells ◽  
Connective Tissue Component ◽  
Pregnancy And Lactation ◽  
The Mean ◽  
Formed Structure

Ovaries from the bandicoots I. macrourus and P. nasuta, collected during pregnancy and lactation, were examined macroscopically and with the light microscope. The mean number of corpora lutea (CL) was greater in I. macrourus (5.13) than in P. nasuta (3.31). This difference in ovulation rate was reflected in the mean number of embryos and the mean number of pouch young respectively (I. macrourus 4.05, 3.07; P. nasuta 2.63, 2.65). During the first few days of pregnancy, the transformation of follicle granulosa cells into luteal cells was accompanied by the intrusion of the theca, which produced a network of blood vessels and connective tissue. A conspicuous feature of the developing CL was the presence of pools of blood between the luteal cells. By 5-6 days of pregnancy, the CL was a fully formed structure, the central cavity having been filled in by hypertrophy of the luteal cells and an increase in the connective tissue which formed a central core. The luteal cells had almost reached their maximum size and they contained numerous lipid droplets. Mitoses of luteal cells were not evident at any stage in the formation of the CL or later, though some of the luteal cells had two or more nuclei. The structure of the CL and the diameter of the luteal cells and their nuclei remained almost constant until regression occurred after the 45th day of the 60-day lactation period. Regression of the CL was characterized by a marked reduction in the size of the luteal cells and their nuclei as well as an increase in the connective tissue component. Diameters and volumes of the CL were similar in the two species, reaching maxima during the second half of pregnancy and changing very little until the 45th day of lactation, after which they decreased rapidly. This decline occurred whether or not the animals subsequently ovulated during the last quarter of the lactation period.

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