Reproduction in Peradorcas-Concinna (Marsupialia, Macropodidae)

1986 ◽  
Vol 13 (4) ◽  
pp. 501 ◽  
Author(s):  
JE Nelson ◽  
A Goldstone
Keyword(s):  
Cycle Length ◽  
Oestrous Cycle

The length of the oestrous cycle in captive Peradorcas concinna was 33.73 � 1.65 days (n = 52). Females which were dominant over other females or were alone with their young had a cycle length of about 32 days and subordinate females had a cycle length of about 35 days. Some observations on the growth of the young are presented. Weaning is very abrupt; final pouch exit occurs about 2 weeks after the first pouch exit, and is caused by the female's aggressiveness towards its young.

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.

The effects of single injections of progesterone on oestrous cycle length in ewes

1973 ◽  
Vol 80 (3) ◽  
pp. 525-526 ◽  
Author(s):  
I. W. Dixon ◽  
C. J. Thwaites
Keyword(s):  
Cycle Length ◽  
Effective Means ◽  
Post Treatment ◽  
Route Of Administration ◽  
Oestrous Cycle ◽  
Conception Rate ◽  
Factorial Experiment ◽  
Massive Dose ◽  
Intramuscular Injections

SummaryTwo hundred and forty mature Merino ewes were used in a factorial experiment to investigate the effects of single injections of either 0, 40, 80 or 160 mg progesterone on the length of the subsequent oestrous cycle. Equal numbers of ewes (15 per group) received subcutaneous and intramuscular injections, and equal numbers were treated either on the day of oestrus or the following day.Oestrous cycle length was significantly reduced in all treated groups, with a minimum cycle length of 7–10 days following treatment with 80 or 160 mg progesterone. Neither route of administration nor day of treatment significantly affected the response. The conception rate achieved by treated ewes at the first post-treatment oestrus did not differ significantly from that in comparable controls.The results suggest that a single massive dose of progesterone on the day of oestrus is an effective means of shortening the oestrous cycle of the ewe without loss of fertility.

Effects of treatment with a gonadotrophin-releasing hormone analogue on follicle development in dairy cows fed one of two different diets

2001 ◽  
Vol 26 (2) ◽  
pp. 451-455
Author(s):  
E.C.L. Bleach ◽  
C.L. Moore ◽  
H.J. Zeale ◽  
P.G. Knight
Keyword(s):  
Dairy Cows ◽  
Luteal Phase ◽  
Cycle Length ◽  
Crude Protein ◽  
Oestrous Cycle ◽  
Follicle Development ◽  
Releasing Hormone ◽  
Ovulatory Follicle ◽  
Metabolisable Energy ◽  
Phase Length

AbstractFollicle development occurs in two or three waves during the bovine oestrous cycle. Artificially extending the duration of ovulatory follicle dominance influences pregnancy rates in cattle, as does the interval from emergence to oestrus in dairy cows undergoing spontaneous oestrous cycles. The objectives of the presented study were to determine whether the interval from ovulatory follicle emergence to oestrus might be altered by diet and/or gonadotropin-releasing hormone (GnRH) treatment. Lactating primiparous Holstein/Friesian cows (n=21) were randomly allocated to one of two diets at calving (Diet 1, n=ll, DM 480 g/kg, metabolisable energy 12.0 MJ/kg DM crude protein 178 g/kg DM, oil B 48 g/kg DM, neutral detergent fibre 318 g/kg DM and diet 2, n=10, DM 440 g/kg, metabolisable energy 12.1 MJ/kg DM, crude protein 172 g/kg DM, oil B 40 g/kg DM, neutral detergent fibre 300 g/kg DM). From 10 days after observed oestrus (oestrus 1), ovarian follicular and luteal development was monitored by daily transrectal ultrasonography until the subsequent oestrus and ovulation. A GnRH analogue was injected (i.m.; 10 μg) 12 days after oestrus 1 in 6 cows fed diet 1 and 5 cows fed diet 2. Oestrous cycle length was longer (p<0.05) in control cows fed diet 1 than those fed diet 2. Treatment with GnRH increased (p<0.005) cycle length in cows fed diet 2 but not those fed diet 1. Increases in cycle length observed were associated with longer luteal phase length. Follicular phase length was reduced (p<0.05) by GnRH treatment in cows fed diet 1. Ovulatory follicles emerged later (p<0.05) in control cows fed diet 1 than those fed diet 2. GnRH treatment delayed (p<0.01) the emergence of the ovulatory follicle in cows fed diet 2, this delay was associated with an increase (p<0.05) in the incidence of 3 follicle waves in oestrous cycles following GnRH treatment. The interval from emergence of the ovulatory follicle to the subsequent oestrus was similar among the treatment groups. We conclude that treatment with GnRH during the mid-luteal phase may delay the emergence of the ovulatory follicle. However, the response is dependent on diet fed. Where ovulatory follicle emergence is delayed, the interval from emergence to the subsequent oestrus was unaffected since oestrous cycle length is extended.

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 Effect of injected bovine interferon- I1 on oestrous cycle length and pregnancy success in sheep

Reproduction ◽  
1991 ◽  
Vol 91 (1) ◽  
pp. 347-356 ◽  
Author(s):  
T. K. Schalue-Francis ◽  
P. W. Farin ◽  
J. C. Cross ◽  
D. Keisler ◽  
R. M. Roberts
Keyword(s):  
Cycle Length ◽  
Oestrous Cycle

A note on the characteristics of oestrus and ovulation in Awassi ewes

1990 ◽  
Vol 50 (1) ◽  
pp. 198-201 ◽  
Author(s):  
R. Kassem ◽  
J. B. Owen ◽  
I. Fadel
Keyword(s):  
Cycle Length ◽  
Oestrous Cycle ◽  
Ovulation Rate ◽  
Mean Values ◽  
Ewe Lambs ◽  
Awassi Breed

The length of the oestrous cycle observed in 20 ewe lambs and 424 ewes of the Awassi breed gave mean values of 16·4 (s.d. 1·31) days for ewe lambs and 17·4 (s.d. 1·84) days for ewes. Plane of nutrition did not affect cycle length in ewe lambs and age of ewe (from 2 to 5 years) did not affect oestrous cycle length in ewes (P > 0·05). Of 40 ewes treated with progesterone intravaginal sponges 33 (83%) showed oestrus and 28 (70%) ovulated at the first (synchronized) and 31 (78%) and 30 (75%) at the repeat oestrus. Mean duration of oestrus was 40·0 (s.d. 16·37) h (range 8 to 72) for the first and 34·7 (s.d. 11·19) h (range 16 to 54) for the repeat oestrus. Ovulation rate, measured in the same ewes, gave mean values of 1·18 (s.d. 0·460) for the first and 1·223 (s.d. 0·440) for the repeat oestrus.

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&lt;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.

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