Oestrous and ovarian activities of Finn-cross ewes during the post-partum and the seasonal anoestrous periods

1984 ◽  
Vol 103 (1) ◽  
pp. 155-160 ◽  
Author(s):  
D. Amir ◽  
Miriam Rosenberg ◽  
H. Schindler
Keyword(s):  
Sexual Activity ◽  
Reproductive Performance ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Ovarian Activity ◽  
Plasma Progesterone ◽  
Oestrus Induction ◽  
Autumn And Winter

SummaryThe seasonal and post-partum oestrus occurrence and ovarian activity, assessed by the plasma progesterone concentrations, were studied in Finn-cross ewes following autumn and winter lambings.The last seasonal oestrous cycle was followed by a silent ovulation in C0% of the Finn × Awassi ewes. Silent ovulations during midanoestrus occurred in 50% of the ewes, and in 90% of the animals a silent ovulation preceded the normal resumption of the seasonal sexual activity.The first post-partum oestrus occurred within C0 days after October lambings in about 90% of the ewes. Silent ovulations before the first post-partum oestrus were evident in 70% of the recycling ewes.It is suggested that breeding ewes with ovarian activity after oestrus induction during anoestrous periods might increase the reproductive performance of the flock in a frequent lambing system.

Reproduction in the mosaic-tailed rat, Melomys cervinipes (Rodentia :Muridae)

1970 ◽  
Vol 18 (2) ◽  
pp. 171 ◽  
Author(s):  
JM Taylor ◽  
BE Horner
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Post Partum ◽  
Selective Advantage ◽  
Breeding Period ◽  
Mode Of Reproduction ◽  
Accessory Sex Glands ◽  
Modest Contribution ◽  
Northern Regions ◽  
Autumn And Winter

The mosaic-tailed rat, M. cervinipes, is usually an abundant murid where it occurs in the northern regions of Australia. It is an inhabitant of the forests and their fringe associations and is semi-arboreal. Although the annual reproductive performance is unknown, breeding occurs at least in late spring and summer in more southern areas of its distribution and extends into autumn and winter farther north. Litter size ranges from two to four. The nipple-clinging behaviour of the young appears to be of selective advantage as an escape mechanism. Description of the histology of the gonads and accessory sex glands is given for juveniles, breeding adults, and sexually quiescent adults. M. cervinipes is polyoestrous and a spontaneous ovulator and may experience a post-partum oestrus. Melomys is not known to occur in plague proportions in its native habitat; its mode of reproduction favours a prolonged and modest contribution of young within a breeding period.

PERIPHERAL PLASMA PROGESTERONE CONCENTRATION OF COWS DURING PUBERTY, OESTROUS CYCLES, PREGNANCY AND LACTATION, AND THE EFFECTS OF UNDER-NUTRITION OR EXOGENOUS OXYTOCIN ON PROGESTERONE CONCENTRATION

1970 ◽  
Vol 48 (4) ◽  
pp. 599-614 ◽  
Author(s):  
L. E. DONALDSON ◽  
J. M. BASSETT ◽  
G. D. THORBURN
Keyword(s):  
Luteal Phase ◽  
Post Partum ◽  
Late Pregnancy ◽  
Ovarian Activity ◽  
Progesterone Concentration ◽  
Slow Increase ◽  
Normal Cycle ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Pregnancy And Lactation

SUMMARY Progesterone concentrations in the peripheral plasma of cows were measured by a protein-binding radioassay method. The mean concentration was lowest at oestrus (0·44 ng/ml) and then increased to a maximum of 6·8 ng/ml about day 14 of the 21-day cycle. The concentration decreased rapidly during the last 4 days of the cycle, reaching low levels on the day before oestrus. There were no significant changes in progesterone concentration during oestrus. After ovariectomy the plasma progesterone concentration decreased to a very low level (< 0·4 ng/ml). After hysterectomy, progesterone concentrations remained high for longer than in a normal cycle. At puberty, plasma progesterone concentrations indicated cyclic ovarian activity before the first observed oestrus. Daily treatment of cows with oxytocin (0·4 u./kg body weight) from day 2 reduced the oestrous cycle length to 9 days, but did not significantly alter the slow increase in plasma progesterone concentration during the first 5 days of the cycle. Plasma progesterone concentrations decreased again after day 5 to low values. Plasma progesterone concentration during early pregnancy was similar to the luteal phase value (4–6 ng/ml), declined during mid-pregnancy and then increased to a maximum (7–8 ng/ml) at about 240 days gestation. The concentration declined 2–3 weeks before calving. During lactation progesterone concentrations were very low until the resumption of cyclic ovarian activity. The first post-partum cycle, whether accompanied by observed oestrus or not, was usually preceded by a small increase in plasma progesterone concentration 3–5 days before the start of the cycle. Undernutrition significantly increased plasma progesterone concentrations in mid- and late pregnancy. Undernutrition of non-pregnant cows increased progesterone concentrations during the luteal phase of the first cycle, but reduced it in later cycles.

A protocol for initiating oestrus and ovulation earlypost partumin dairy cows

2001 ◽  
Vol 72 (3) ◽  
pp. 539-546 ◽  
Author(s):  
A. O. Darwash ◽  
G. E. Lamming ◽  
M. D. Royal
Keyword(s):  
Reproductive Performance ◽  
Post Partum ◽  
Treatment Protocol ◽  
Ovarian Activity ◽  
Milk Samples ◽  
Management Regime ◽  
Holstein Friesian ◽  
Prostaglandin F ◽  
The Mean ◽  
Friesian Cows

AbstractThe objective of the present study was to evaluate the efficacy of a prostaglandin F2α(PGF2α) and progesterone (P4) treatment in initiating oestrus and ovulation post partum (PP) in Holstein-Friesian cows. Using four herds, the treatment protocol consisted of a single intra-muscular injection of PGF2α(Estrumate) between days 12 to 14 PP followed 48 h later by progesterone treatment via intra-vaginal CIDR insertion for a period of 7 days. Milk samples for progesterone determination were collected three times weekly from 7 to 65 days PP. The ovarian activity and reproductive performance of treated (T, no. = 153) animals and untreated control cows (C, no. = 315) were compared. Treatment was effective (P< 0·001) in reducing the mean interval to PP commencement of luteal activity from 29·62 (s.e. 0·82) days to 22·09 (s.e. 0·70) days. The mean interval to first PP oestrus in the T animals was significantly reduced (P< 0·001) from 55·62 (s.e. 1·58) days to 44·91 (s.e. 1·44) days and the incidence of silent ovulation in cycles between days 21 to 65 PP was reduced (P< 0·001) from 56·28% to 42·27%. In two herds under one management regime and with a similar block-calving pattern (no. = 280 animals), the treatment protocol was beneficial to the overall reproductive performance as there was a significant shortening in the mean interval to first PP service (75·82 (s.e. 1·93) v. 80·86 (s.e. 1·32) days) and in the interval to PP conception (83·07 (s.e. 2·49) v. 88·90 (s.e. 1·95) days), bothP< 0·05.

Studies on plasma progesterone concentrations and fertility in Friesland dairy cows during the post-partum period

1981 ◽  
Vol 97 (3) ◽  
pp. 649-654 ◽  
Author(s):  
D. H. Holness ◽  
G. W. Sprowson ◽  
Carole Sheward ◽  
Amanda Geel
Keyword(s):  
Dairy Cows ◽  
Early Pregnancy ◽  
Post Partum ◽  
Ovarian Activity ◽  
Plasma Progesterone ◽  
Low Concentrations ◽  
The Mean ◽  
Post Partum Period ◽  
Embryo Loss

SUMMARYPlasma progesterone concentrations were monitored in 69 lactating Friesland dairy cows during the post-partum period. Cyclic ovarian activity resumed in most cows within 40 days of calving. Forty-eight per cent of cows remained pregnant to their first insemination, 41% returned to oestrus before day 30 after insemination, and a further 11% returned to oestrus between days 30 and 88 after insemination.The mean of progesterone values on days 11 to 4 before insemination tended to be higher in cows that conceived than in cows that did not conceive. These differences were signficant on day –8 (P <0·05) and on days –8, –7, –6 and –5 combined (P <0·01). Cows in which the concentration of progesterone in plasma did not rise above 4·5 ng/ml during this period did not conceive. After insemination, mean progesterone concentrations between pregnant and non-pregnant cows diverged after day +8. Relatively low concentrations of plasma progesterone (< 1 ng/ml) up to day +8 after insemination did not preclude conception. There was no indication that embryo loss between days +30 and +88 after insemination was related to an insufficiency of ovarian progesterone during early pregnancy.

scholarly journals Ovarian activity in Fleckvieh, Brown Swiss and two strains of Holstein-Friesian cows in pasture-based, seasonal calving dairy systems

2011 ◽  
Vol 78 (4) ◽  
pp. 464-470 ◽  
Author(s):  
Valérie Piccand ◽  
Susanne Meier ◽  
Erwan Cutullic ◽  
Sara Weilenmann ◽  
Peter Thomet ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Body Condition Score ◽  
Post Partum ◽  
Oestrous Cycle ◽  
The Other ◽  
Breeding Period ◽  
Ovarian Activity ◽  
Brown Swiss ◽  
Holstein Friesian ◽  
Condition Score

The objectives of the study were to compare the ovarian activity of Holstein-Friesian (CH HF), Fleckvieh (CH FV) and Brown Swiss (CH BS) dairy cows of Swiss origin with that of Holstein-Friesian (NZ HF) dairy cows of New Zealand origin, the latter being used as a reference for reproductive performance in pasture-based seasonal calving systems. Fifty, second-lactation NZ HF cows were each paired with a second-lactation Swiss cow (17, 15 and 18 CH HF, CH FV and CH BS respectively) in 13 pasture-based, seasonal-calving commercial dairy farms in Switzerland. Ovarian activity was monitored by progesterone profiling from calving to first breeding service. CH BS cows produced less energy-corrected milk (mean 22·8 kg/d) than the other breeds (26·0–26·5 kg/d) during the first 100 d of lactation. CH HF cows had the lowest body condition score (BCS) at calving and the greatest BCS loss from calving to 30 d post partum. Commencement of luteal activity (CLA) was later for NZ HF than for CH FV (51·5 v. 29·2 d; P <0·01), with CH HF and CH BS intermediate (43 d). On average, NZ HF and CH HF cows had one oestrous cycle before the onset of the seasonal breeding period; this was less (P<0·01) than either CH FV (1·7) or CH BS (1·6). There was a low prevalence of luteal persistency (3%) among the studied cows. First and second oestrous cycle inter-ovulatory intervals did not differ between breeds (20·5–22·6 d). The luteal phase length of CH BS during the second cycle was shorter (10·6 d) than that of the other breeds (13·8–16·0 d), but the inter-luteal interval was longer (9·8 d v. 7·0–8·0 d). The results suggest that the Swiss breeds investigated have a shorter interval from calving to CLA than NZ HF cows.

The incidence of prolonged luteal function following early resumption of ovarian activity in post partum dairy cows

1998 ◽  
Vol 1998 ◽  
pp. 187-187
Author(s):  
P.J.H. Ball ◽  
E.E.A. McEwan
Keyword(s):  
Dairy Cows ◽  
Reproductive Performance ◽  
Early Onset ◽  
Post Partum ◽  
Subsequent Pregnancy ◽  
Ovarian Activity ◽  
Luteal Function ◽  
Milk Samples

Early onset of ovarian activity post partum is thought to benefit reproductive performance in dairy cows (e.g. Darwash et al., 1997). However, as in the lactating ewe (Aitken et al., 1995), very early resumption may be detrimental to subsequent conception. An experiment was conducted to determine whether cows commencing ovarian activity very early would be more likely to suffer problems such as prolonged luteal function.Milk samples were collected from 133 individual multiparous cows three times a week, from approximately one week after calving until the subsequent pregnancy was well established. Profiles of progesterone, measured by ELISA, were used to detect the start of ovarian activity, prolonged luteal function (high values until 24 or more days after the start of ovarian activity or subsequent ovulations), and pregnancy.

Anoestrus in the red kangaroo Megaleia rufa (Desmarest).

1964 ◽  
Vol 12 (1) ◽  
pp. 9 ◽  
Author(s):  
AE Newsome
Keyword(s):  
Luteal Phase ◽  
Post Partum ◽  
Arid Environment ◽  
Adaptive Significance ◽  
Oestrous Cycle ◽  
Ovarian Activity ◽  
Previous Pregnancy ◽  
Quiescent Period ◽  
Red Kangaroo ◽  
Prolonged Drought

The red kangaroo, M. rufa, normally has a post-partum oestrus and a quiescent period of lactation as do some other macropod marsupials. The term "quiescent period of lactation" has been defined in this paper as the period of reproductive stasis between post-partum oestrus and the resumption of ovarian activity which follows when the female ceases, or almost ceases to suckle the young. This term is introduced to replace the term "lactation anoestrus". It has been shown that some females failed to undergo post-partum oestrus during prolonged drought, each female having entered anoestrus during the previous pregnancy; such pregnancies were not interrupted, but carried to term, and the young sometimes suckled for 3-4 months. In some other females, anoestrus set in during an unfertilized oestrous cycle. It is thought that anoestrus may result from lack of food because anoestrous females are found only during prolonged drought. The histology of the uteri of lactating anoestrous females has been described, and shown to be indistinguishable from that of the uteri of non-lactating anoestrous females, and very different from that in animals in the quiescent period of lactation. The anoestrous condition appeared in the uterus after the cessation of the luteal phase. Pregnancy is therefore independent of the oestrous cycle in Megaleia when the luteal phase has passed. The onset of anoestrus in Megaleia is compared with that in Elephantulus rupestris jamesoni Chubb, Sorex araneus (L.), Oryctolagus cuniculus (L.), Setonix brachyurus (Quoy & Gaimard), and Potorous tridactjhs (Kerr), all of which usually undergo post-partum oestrus. In Oryctolagus and Elephantulus, anoestrus may lead to the death respectively of the young and foetus. It is suggested that the milder consequences of anoestrus in Megaleia may be of adaptive significance to the species in a semi-arid environment, since the embryos and pouch-young of anoestrous females have a chance to survive drought.

The effect of artificial light, hormones, and rams on the reproductive performance of Finn-cross ewes during the seasonal anoestrus in Israel

1985 ◽  
Vol 105 (2) ◽  
pp. 375-379 ◽  
Author(s):  
D. Amir ◽  
H. Gacitua
Keyword(s):  
Electrical Impedance ◽  
Hormone Treatment ◽  
High Rate ◽  
Ovarian Activity ◽  
Natural Control ◽  
Abrupt Increase ◽  
Plasma Progesterone ◽  
Artificial Photoperiod ◽  
Ram Effect ◽  
Oestrus Induction

SUMMARYAdult Finn-cross ewes, pregnant from September matings, were kept under natural (control) or artificial photoperiod (experimental). The artificial photoperiod consisted of an abrupt increase in daylength to 18 h for 30 days in November, followed by a step wise decrease of 30 min every 10 days until May.The ewes of the two groups were either exposed daily to rams after lambing in January-February or after weaning in March, or were kept isolated from the males until mating in April. Time of mating in the latter animals was determined by measuring the intra-vaginal electrical impedance. Hormone treatment for oestrus induction was given after weaning to a portion of the control and experimental ewes. The ovarian activity of the animals was determined by examining their plasma progesterone changes.Daily teasing of the ewes from lambing to weaning and/or treatment with artificially decreasing daylength did not influence the ovarian activity during this period. All the ewes which were examined for ovulation, from both the control and experimental groups, ovulated 40–60 days after lambing, and 96% of the animals of the two groups which were not treated with hormones for oestrus induction exhibited spontaneous oestrus in March–May.The lambing–first ovulation and the lambing–first spontaneous oestrus intervals were longer in the light-treated than in the control ewes, and in the animals kept isolated from the rams until mating than in those exposed to the males after lambing or weaning.A conception rate of 70–100% and a high rate of cycle activity were obtained during the two consecutive years of the experiment in both control and experimental animals, treated or not with hormones and exposed or not to rams. In view of these results, no conclusions could be drawn about the effectiveness of the artificial photoperiod, ram effect and hormone treatment, alone or in combination, in inducing cycling activity and to increase the fertility of Finn-cross ewes during the seasonal anoestrus in Israel.

A note on the effect of zeranol administration on oestrous cycle length and hormonal profiles in cows

1986 ◽  
Vol 42 (3) ◽  
pp. 421-424
Author(s):  
W. E. Beal ◽  
G. A. Good ◽  
D. J. Putney ◽  
G. L. Johnson
Keyword(s):  
Beef Cattle ◽  
Cycle Length ◽  
Post Partum ◽  
Beef Cows ◽  
Oestrous Cycle ◽  
Plasma Progesterone ◽  
Anabolic Agent ◽  
Hormonal Profiles ◽  
Cycle Lengths

ABSTRACTZeranol is an anabolic agent with oestrogenic actions commonly used in fattening beef cattle. This experiment was designed to determine the effects of zeranol administration on oestrous cycle lengths, plasma progesterone concentrations and the exhibition of oestrus in mature cows. Administration of 36-mg zeranol implants during the early, middle or later portion of the oestrous cycle did not alter the length or persistence of oestrous cycles, nor were progesterone profiles different from those observed in untreated cows. Some cows that received zeranol exhibited a prolonged oestrus. The regularity of oestrous cycles in cows treated with zeranol indicates that it may be possible to utilize zeranol as an anabolic and lactopoetic agent in post-partum beef cows.

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