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.).

STUDIES ON THE BIOLOGY OF THE MUSKRAT IN MANITOBA: PART I. OESTROUS CYCLE AND BREEDING SEASON

1952 ◽  
Vol 30 (4) ◽  
pp. 243-253
Author(s):  
J. A. McLeod ◽  
G. F. Bondar
Keyword(s):  
Breeding Season ◽  
Cycle Length ◽  
Oestrous Cycle ◽  
Minimum Time ◽  
Vaginal Smear ◽  
In Captivity ◽  
In The Wild ◽  
The Mean ◽  
Time Required ◽  
Mean Time

A study of oestrus in female muskrats was conducted during the summers of 1950 and 1951 as part of a five year investigation of the biology of the muskrat in Manitoba. Two captive females examined daily by the vaginal smear method from June 30 to Aug. 10, 1950, inconclusively indicated an oestrous cycle length of about 30 days which agreed with the findings of Beer on Wisconsin muskrats. In 9151 10 female muskrats of various ages and of different lengths of time in captivity were examined daily beginning on March 13 and continuing until August 15. The data obtained at this time showed a considerable variation in the lengths of the oestrous cycles in different females or, even, in the same individual from time to time. The minimum time required for the completion of an oestrous cycle was found to be two days while the maximum time observed was 22 days. On the basis of 136 complete oestrous cycles studied, the modal time was found to be approximately four days and the mean time 6.1 days. The longer cycles found by ourselves in 1950 and by Beer are interpreted as representing pseudopregnancies and not oestrous cycles. Failure of muskrats to mate in captivity or in the wild during the latter part of the summer is attributed to sexual inactivity of the males and not the females.

The effect of the laparoscopic insemination technique on the oestrous cycle of the ewe

1991 ◽  
Vol 62 (2) ◽  
pp. 60-61
Author(s):  
T. L. Taljaard ◽  
S. J. Terblanche ◽  
H. J. Bertschinger ◽  
L. J. Van Vuuren
Keyword(s):  
Cycle Length ◽  
Intrauterine Insemination ◽  
Uterine Horn ◽  
Oestrous Cycle ◽  
Control Group ◽  
Control Groups ◽  
The Mean ◽  
And Control ◽  
Pregnant Mare Serum Gonadotrophin ◽  
Teaser Rams

This investigation was designed to determine whether or not the technique of intrauterine insemination affects the length of the subsequent oestrous cycle. Dorper ewes (n=31) were divided into treatment and control groups. All the ewes were synchronised using 40 mg fluorogestone acetate intravaginal sponges for 14 d and 300 IU pregnant mare serum gonadotrophin on the day of sponge removal. A standard semen diluent was deposited laparoscopically in each uterine horn of ewes in the treatment, group. Teaser rams were used to detect oestrus. Progesterone profiles were used to confirm oestrus. The mean oestrous cycle length of 17,83 ± 0,69 d for the group in which the diluent was deposited by laparoscopy did not differ significantly (P0,l) from the 18,36±2,11 d of the control group. The technique of laparoscopic insemination did not influence the length of subsequent oestrous cycles.

CONTRACEPTION BY AN INJECTABLE, LONG-ACTING OESTROGEN-PROGESTOGEN AGENT

1969 ◽  
Vol 61 (3) ◽  
pp. 494-508 ◽  
Author(s):  
Rolf Plesner
Keyword(s):  
Cycle Length ◽  
Normal Amount ◽  
Basal Body Temperature ◽  
Secretory Phase ◽  
Inhibiting Effect ◽  
Excretion Pattern ◽  
The Mean ◽  
Long Acting ◽  
Mean Cycle ◽  
Fertile Women

ABSTRACT The author reports the results of a clinical study on 17 fertile women treated through a total of 120 cycles with Deladroxate, an injectable, long-acting oestrogen-progestogen. The injections were administered on the 8th (7th–9th) day of each cycle. Before treatment was started, the patients were observed through 2 cycles with regard to cycle length as well as duration and amount of flow. Moreover, ovulation was assessed by means of daily recording of basal body temperature (BBT), pregnanediol analyses, total pituitary gonadotrophin analyses, and endometrial biopsies. In some cases the dosage had to be increased because of a shortening of the cycle. The mean cycle length during the treatment was 24.2 days, though with fairly marked variations (mean cycle length before institution of treatment: 28.2 days). Duration of flow ranged from 3–35 days. About 84% of 108 withdrawal bleedings lasted for 4–8 days. Of the flows 56 % were of normal amount, while the majority of the remaining 44 % were scantier than in the patients with normal periods. The ovulation-inhibiting effect of Deladroxate was assessed by daily recording of BBT, pregnanediol and pituitary gonadotrophin assays, and endometrial biopsies. Five of the 41 BBT curves (41 cycles) were biphasic. Four out of 34 endometrial biopsies, obtained on the 23rd day of the cycle, showed a secretory phase. Forty out of 41 cycles were anovulatory, as assessed by the pregnanediol excretion, while in 1 cycle the excretion pattern was not characteristic. In 20 out of 37 cycles there was a definite depression of gonadotrophin excretion, while in 17 cycles the excretion pattern was not characteristic. The effect of Deladroxate on the adrenal cortex was studied by means of 17-ketogenic steroid and 17-ketosteroid excretion. With both groups of steroids there seemed to be a tendency to a reduced excretion during treatment. No changes in the fibrinogen, prothrombin, GO-transaminase, bilirubin, or thymol values were observed during treatment. Side effects during treatment, recorded in 11 of the 17 subjects, were in most cases slight and transient. The most common complaints were breast tenderness, oedema, and irregularities of bleeding. No pregnancy occurred during treatment.

Effects of stress on ovarian morphology and oestrus cycles in ewes

1964 ◽  
Vol 15 (6) ◽  
pp. 937 ◽  
Author(s):  
AWH Braden ◽  
GR Moule
Keyword(s):  
Corpus Luteum ◽  
Breeding Season ◽  
Cycle Length ◽  
Acute Stress ◽  
Oestrous Cycle ◽  
Large Cavity ◽  
Severe Stress ◽  
Microscopic Appearance ◽  
Ovarian Morphology ◽  
Luteal Tissue

Observations involving over 600 sheep and extending over 4 years were made on the effect of acute stress on the oestrous cycle and ovarian morphology of ewes. In anoestrous ewes ovulation unaccompanied by oestrus was often induced by severe stress. Injections of ACTH did not induce ovulation in anoestrous ewes. During the breeding season severe stress appeared sometimes to lengthen the oestrous cycle by a few days. The presence of a large cavity in the corpus luteum (C.L.) often seemed to have been induced by stress, but the amount of luteal tissue and its microscopic appearance did not usually appear much different from solid C.L. Oxytocin injections did not affect oestrous cycles or ovarian morphology, but in some circumstances injections of ACTH or stilboestrol appeared to cause an increase in cycle length.

scholarly journals The Phases of the Oestrous Cycle in the Adult White Rat

1951 ◽  
Vol 28 (4) ◽  
pp. 576-584
Author(s):  
ANITA M. MANDL
Keyword(s):  
Cycle Length ◽  
The Body ◽  
Oestrous Cycle ◽  
Adult Rats ◽  
Significant Fluctuation ◽  
The Mean

The duration of the oestrous cycle in thirty-nine adult rats derived from ten litters was 4.4 ± 0.04 days. The variance in cycle length tended to be less within than between litter-groups (P≏0.05). It was significantly less for individual rats than between individuals (P<0.001). The mean duration of early oestrus was 18 hr., oestrus 25 hr., late oestrus 5 hr., early dioestrus 24 hr., dioestrus 28 hr. and late dioestrus 7 hr. The length of the dioestrous phase is variable and determines the length of the cycle, while the duration of oestrus appears to be relatively constant. The figures have been compared with those published by other laboratories. Analyses of variance did not disclose any significant fluctuation in the weight of the body, adrenals or ovaries in phase with the oestrous cycle. The uterus showed a characteristic increase in weight immediately before the onset of oestrus.

Reproduction in Sminthopsis-Longicaudata (Marsupialia, Dasyuridae) - Laboratory Observations

1986 ◽  
Vol 13 (1) ◽  
pp. 7 ◽  
Author(s):  
PA Woolley ◽  
A Valente
Keyword(s):  
Endangered Species ◽  
Breeding Season ◽  
Early Summer ◽  
Oestrous Cycle ◽  
Gestation Period ◽  
Late Winter ◽  
Breeding Condition ◽  
Males And Females ◽  
The Mean

Observations on the pattern of reproduction in Sminthopsis longicaudata, at present considered to be an endangered species, are presented. S. longicaudata is polyoestrous and in the laboratory females are in breeding condition from late winter (August) to early summer (December). They enter oestrus up to four times during the breeding season. Two litters were born 17 and 19 days post-mating, but the gestation period may be less than 15 days. The mean length of the oestrous cycle is 34.4 days. Both males and females may be able to breed in more than one season.

Cycle day of ovulation

1972 ◽  
Vol 4 (4) ◽  
pp. 371-378 ◽  
Author(s):  
William H. James
Keyword(s):  
Cycle Length ◽  
Composite Sample ◽  
Normal Length ◽  
Menstrual Cycles ◽  
The Mean ◽  
Long Cycles ◽  
The One ◽  
The Individual ◽  
Mean Cycle

The length of the post-ovulatory phase in a composite sample of menstrual cycles increases linearly with cycle length until cycle length reaches about 30 days, but thereafter it ceases to increase (Vollman, 1953; Bailey & Marshall, 1970). By contrast, plotted against the mean cycle length of the individual, the length of the post-ovulatory phase continues to increase roughly linearly with mean cycle length. It is concluded (a) that many long cycles are aberrant occurrences among cycles of normal length and are due to lengthening of the pre-ovulatory phase and (b) that where the mean cycle length is long, ovulation, as in shorter cycles, occurs just before the middle of the cycle, so that the post-ovulatory phase is longer than usual.The most fertile day seems to be the one before mid-cycle. These conclusions are the basis for the following formula for calendar rhythm:If x is the shortest and y the longest cycle in a woman's menstrual record, the ‘unsafe’ days start on Day (½x − 5) and last for (y − x + 8) days.

Characteristics of the menstrual cycle in nonhuman primates. IV. Timed mating in Macaca nemestrina

1981 ◽  
Vol 15 (4) ◽  
pp. 351-353 ◽  
Author(s):  
G. B. Blakley ◽  
T. W. Beamer ◽  
W. R. Dukelow
Keyword(s):  
Menstrual Cycle ◽  
Cycle Length ◽  
Nonhuman Primates ◽  
Macaca Nemestrina ◽  
Optimal Time ◽  
Macaque Species ◽  
A Value ◽  
The Mean ◽  
Perineal Swelling ◽  
Mean Cycle

The events of the perineal swelling cycle in Macaca nemestrina have been correlated with the optimal time for conception. The mean cycle length of the animals was 32·8 days with the follicular and luteal phases of the cycle 17·6-19·2 and 13·6-15·2 days respectively. The time of ovulation, relative to the tumescence peak, ranged from 1 to 13 days. The optimal time for mating, based on the ratio between day of breeding and cycle length was 0·46, a value comparable with similar calculations for other macaque species.

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.

Reproductive biology of captive southern hairy-nosed wombats (Lasiorhinus latifrons). Part 1: oestrous cycle characterisation

2018 ◽  
Vol 30 (11) ◽  
pp. 1412 ◽  
Author(s):  
Alyce M. Swinbourne ◽  
Stephen D. Johnston ◽  
Tina Janssen ◽  
Alan Lisle ◽  
Tamara Keeley
Keyword(s):  
Epithelial Cells ◽  
Specific Gravity ◽  
Luteal Phase ◽  
Cycle Length ◽  
Urine Volume ◽  
Follicular Phase ◽  
Oestrous Cycle ◽  
Urine Specific Gravity ◽  
The Mean ◽  
Late Follicular Phase

Southern hairy-nosed wombats (SHNWs: Lasiorhinus latifrons) do not breed well in captivity. To better understand their reproduction, daily urine samples were collected from nine captive females and analysed for volume (mL), specific gravity and a qualitative index of the number of epithelial cells, then stored at −20°C until samples could be analysed for progesterone metabolites (P4M). The mean oestrous cycle length was 35.1 ± 2.4 days; however, individual cycle length ranged from 23 to 47 days. The mean luteal phase length was 20.8 ± 1.3 days (range: 12 to 33 days). Urinary P4M was divided into four oestrous cycle stages: (1) early follicular phase, (2) late follicular phase, (3) early luteal phase, (4) late luteal phase, and analysed against urinary characteristics. During the late follicular phase, urine volume decreased (P = 0.002) while urine specific gravity (P = 0.001) and concentration of epithelial cells (P = 0.004) both increased. The level of variability in oestrous cycle length suggests that some captive females may exhibit abnormal cycles; however, the changes in the urinary characteristics associated with the different stages of the oestrous cycle appear to offer a possible non-invasive means of monitoring the reproductive status of captive SHNWs.

Sign in / Sign up

Export Citation Format

Share Document