Plasma concentrations of progesterone, oestradiol, LH and 15-ketodihydro-PGF2  in Norwegian semi-domestic reindeer (Rangifer tarandus tarandus) during their first reproductive season

Ropstad, Erik; Forsberg, M.; Je, Sire; Kindahl, H.; Nilsen, Turid; Pedersen, Øyvind; Le, Edqvist

doi:10.1530/jrf.0.1050307

Cited by 24 publications

(16 citation statements)

References 11 publications

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“…The failure to identify an association between estradiol level and antler cleaning in adult reindeer (Bubenik et al 1997) almost certainly occurred because the 3-week sampling interval was too long to detect subtle changes in estradiol concentrations. The mid-July estradiol peak of 26 pg/mL in one of our female calves is within the preovulatory range (Ropstad et al 1996), but we were unable to confirm whether or not this was associated with an ovulation. While this female did not conceive, another calf became pregnant in November, approximately 1.5 months after her antlers were cleaned and hardened.…”

Section: Figmentioning

confidence: 65%

Characteristics of first-antler growth in reindeer and their association with seasonal fluctuations in steroid and insulin-like growth factor 1 levels

Blake¹,

Rowell²,

Suttie³

1998

Can. J. Zool.

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Growth and development of the pedicles and first antlers were monitored in seven reindeer (Rangifer tarandus tarandus) calves (three males, four females) from birth to 1 year of age. Calves were weighed, blood was sampled, and antler observations and (or) measurements were taken on the day of birth and days 2, 4, and 7 and then at weekly intervals for the remainder of the year. Prior to measurable growth, the frontal lateral crest was carefully palpated for evidence of pedicle initiation, starting on the day of birth. Calves were born between April 8 and 26, 1994. Pedicle initiation occurred in all reindeer by day 7. Velvet skin first appeared when calves were 4-6 weeks old, when estimated pedicle height was 3.5 ± 0.9 cm (mean ± SD). Antler growth in both sexes followed a sigmoidal pattern, producing a mean antler length of 33.5 ± 4.2 and 46.7 ± 13.8 cm in females and males, respectively. Antler growth was complete by week 18 in females and week 21 in males. Velvet cleaning was associated with a significant increase in plasma testosterone levels in males and estradiol-17β (but not testosterone) levels in females. Insulin-like growth factor 1 levels were significantly higher in males than in females and were positively correlated with the period of most rapid antler growth in both sexes. Casting occurred between March 14 and April 17, when steroid levels were at a minimum, and was immediately followed by growth of the second antler.Résumé : La croissance et le développement du pédoncule et des premiers bois ont été suivis chez sept jeunes rennes (Rangifer tarandus tarandus) (trois mâles, quatre femelles) de la naissance à l'âge de 1 an. Les jeunes rennes ont été pesés, ils ont subi une prise de sang et les observations et (ou) mesures de leurs bois ont été relevées le jour de leur naissance, les jours 2, 4 et 7 après leur naissance, puis à intervalles de 1 semaine pendant le reste de l'année. Avant que la croissance ne soit mesurable, la crête latérale frontale a été palpée avec soin à partir du jour de la naissance, afin de constater très exactement à quel moment apparaît le pédoncule. Les jeunes sont nés entre le 8 et le 26 avril en 1994; la présence du pédoncule a été repérée moins de 7 jours après la naissance chez tous les jeunes. Le velours est apparu à l'âge de 4-6 semaines, au moment où la hauteur du pédoncule était de 3,5 ± 0,9 cm (moyenne ± écart type). La croissance des bois, aussi bien chez les femelles que chez les mâles, suivait un tracé sigmoïde aboutissant à des bois de longueur moyenne de 33,5 ± 4,2 cm chez les femelles et de 46,7 ± 13,8 cm chez les mâles. La croissance était terminée à l'âge de 18 semaines chez les femelles et à l'âge de 21 semaines chez les mâles. Le nettoyage du velours était associé à une augmentation significative de la testostérone plasmatique chez les mâles et de l'estradiol-17B (pas de la testostérone) chez les femelles. Les concentrations du facteur de croissance 1 (de type insuline) se sont avérées significativement plus élevées chez les mâles que chez les femelles et ét...

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Section: Figmentioning

confidence: 65%

Characteristics of first-antler growth in reindeer and their association with seasonal fluctuations in steroid and insulin-like growth factor 1 levels

Blake¹,

Rowell²,

Suttie³

1998

Can. J. Zool.

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“…During 64 the remaining 95 days of pregnancy, poor body con¬ dition reflected in dressed weights apparently has a major influence on the foetus growth as found by Skogland (1984). Factors explaining foetus weight variations may include area, mother's age (Table 4), dressed weight (Skogland, 1984; Table 1), the ovula¬ tion pattern (Ropstad et al, 1995) and the conception date. The ovulation pattern, i.e.…”

Section: Discussionmentioning

confidence: 99%

“…The ovulation pattern, i.e. the number of days between two ovulations, is 21 days among reindeer (Ropstad et al, 1995). Without conception, the female continues to ovulate every 21 day at least up to 6 times (Ropstad et al, 1995).…”

Section: Discussionmentioning

confidence: 99%

“…the number of days between two ovulations, is 21 days among reindeer (Ropstad et al, 1995). Without conception, the female continues to ovulate every 21 day at least up to 6 times (Ropstad et al, 1995). Judging from the calv¬ ing season, which within areas are rather concentrat¬ ed, the majority of females give birth within 10 days, the females breed synchronized and most of them apparently during two ovulations (Table 3).…”

Section: Discussionmentioning

confidence: 99%

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Calving time and foetus growth among wild reindeer in Norway

Reimers

2002

Ran

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Mean calving dates among 7 wild reindeer (Rangifer t. tarandus) herds in southern Norway varied between the 6th and the 27th of May. Ln transformed foetus weights relate linearly to ln age in days. Regression analyzes based upon 225 days pregnancy predicts birth wet weights between 4600 and 7500 g in the different areas and years. At 130 days, foetus weights varied between 547 and 746 g (x=681, standard deviation s=63) in all areas and years, indicating that foetus growth up to this size is independent of mothers body weight or condition. During the remaining 95 days of pregnancy, very poor body condition, reflected in dressed weights, resulted in slower foetus growth and smaller regression estimated birth weights. The foetus weight variation recorded at similar dates within areas and sampling years indicates a dispersed breeding time mostly within two ovulations. A small sample of foetuses from pregnant yearlings and calves indicate that these cohorts conceive later than 2 yr + females. Assuming similar foetus growth pattern among all female age cohorts within areas, yearlings conceive around 1 week later and calves (in Ottadalen) more than 3 weeks later than 2 + yr olds.

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“…1976) in mares (Stabenfeldt et al. 1981) in Norvegian semi‐domestic reindeer (Ropstad et al. 1995) and in female of other species.…”

Section: Regressive Changes and Remodelling Of The Endometriummentioning

confidence: 99%

The Role of the Endometrium in Endocrine Regulation of the Animal Oestrous Cycle

Krzymowski

Stefańczyk-Krzymowska

2007

Reprod Domestic Animals

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A critical analysis of the results of research in the function of the endometrium was carried out and a view point presented. The role of the endometrium in endocrine regulation of the oestrus cycle can be summarized as follows: 1. The transfer of prostaglandin F(2alpha) (PGF(2alpha)) from the uterus to an ovary, which causes luteolysis, occurs mainly via the lymphatic pathways. 2. The system of retrograde transfer of PGs enables PGF(2alpha) and PGE(2) to reach the myometrium and endometrium with arterial blood at high concentration. In the luteal phase, PGF(2alpha), together with the increasing concentration of progesterone, constricts the arterial vessels of the uterus; in the follicular phase and in early pregnancy, PGE(2) together with oestrogen and embryonic signals, relaxes the arterial vessels. In addition, this system protects the corpus luteum from premature luteolysis during the cycle and luteolysis during early pregnancy. 3. In days 10-12 of the cycle, the blood flow in the uterus decreases by 60-70% in pigs and around 90% in sheep. This causes ischaemia and local hypoxia confirmed by the presence of hypoxia inducible factor and thus remodelling of the endometrium commences. 4. The pulsatile elevations in PGF(2alpha) concentration occurring in the blood flowing out of the uterus during the period of luteolysis and the next few days, do not result from increased PGF(2alpha) synthesis as suggested in numerous studies. They are the effect of excretion of PGF(2alpha) and its metabolites together with lymph and venous blood and tissue fluids in which prostaglandin accumulates.

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Plasma concentrations of progesterone, oestradiol, LH and 15-ketodihydro-PGF2 in Norwegian semi-domestic reindeer (Rangifer tarandus tarandus) during their first reproductive season

Cited by 24 publications

References 11 publications

Characteristics of first-antler growth in reindeer and their association with seasonal fluctuations in steroid and insulin-like growth factor 1 levels

Characteristics of first-antler growth in reindeer and their association with seasonal fluctuations in steroid and insulin-like growth factor 1 levels

Calving time and foetus growth among wild reindeer in Norway

The Role of the Endometrium in Endocrine Regulation of the Animal Oestrous Cycle

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