Effect of pattern of lighting and time of birth on occurrence of puberty in female goat kids

1984 ◽  
Vol 38 (1) ◽  
pp. 83-89 ◽  
Author(s):  
E. A. Amoah ◽  
M. J. Bryant

ABSTRACTThirty-six British Saanen female kids, born between either 20 March and 6 April (E) or 10 April and 16 June (L), were reared under three different patterns of lighting — a constant 18-h light: 6-h dark (C); or a weekly step-wise reduction from 18-h to 10-h light: 14-h dark over 10 weeks, commencing at either 6 (R6) or 10 (R10) weeks of age. Vasectomized males were used to test for oestrus; blood samples were collected to determine plasma progesterone concentration. Thirty-three goats attained puberty; all but two kids showed oestrus at first ovulation. The mean ( ± s.d.) age and live weight at puberty were 174·6 (± 4·1) and 141·7 (± 4·3) days (P < 0·001), and 28·6 (± 0·9) and 22·8 (± 1·0) kg (P < 0·001), for E and L treatments, respectively. For R6, R10 and C treatments, the ages and weights wer e 151·6 (± 4·7), 160·4 (± 5·2) and 164·7 (± 4·9) days (NS), respectively, and 24·5 (± 1·1), 25·3 (± 1·2) and 27·8 (± 1·1) kg (NS), respectively. A significant date of birth × lighting-pattern treatment interaction was found for date at puberty (P < 0·001), with puberty occurring earlier for E than L kids only when a reduction in daylength occurred. Puberty occurred earlier on R6 than R10 treatments only for L kids.

1967 ◽  
Vol 55 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Benno Runnebaum ◽  
Josef Zander

ABSTRACT Progesterone was determined and identified in human peripheral blood during the preovulatory period of the menstrual cycle, by combined isotope derivative and recrystallization analysis. The mean concentration of progesterone in 1.095 ml of plasma obtained 9 days before ovulation was 0.084 μg/100 ml. However, the mean concentration of progesterone in 1.122 ml of plasma obtained 4 days before ovulation was 0.279 μg/100 ml. These data demonstrate a source of progesterone secretion other than the corpus luteum. The higher plasma-progesterone concentration 4 days before ovulation may indicate progesterone secretion of the ripening Graafian follicle of the ovary.


1982 ◽  
Vol 100 (2) ◽  
pp. 279-284 ◽  
Author(s):  
R. C. Arora ◽  
R. S. Pandey

Abstract. Domestic buffaloes were used to characterize the pattern of progesterone, oestradiol-17β, LH and androgen in the systemic circulation following infertile insemination. Concentrations of hormones were measured by RIA in blood samples collected daily or at alternate days following insemination. The concentration of progesterone was lowest on the day of insemination, and increased significantly to a peak level of 4.00 ± 0.60 ng/ml by day 13 post insemination. After day 17, it declined significantly (P < 0.01) to reach low levels by day 21. The concentration of oestradiol-17β was high at the time of insemination and declined significantly (P < 0.01) by day 2 after insemination. It was maintained around the basal level till day 18 with minor peaks in between this period. It again rose significantly (P < 0.01) at subsequent oestrus. The mean level of LH was highest at the time of insemination, and declined significantly (P < 0.01) by day 1 post insemination. It did not vary appreciably till the animal returned to oestrus. The oestrous value of LH and progesterone were negatively correlated (r = −0.77). The androgen level was observed to be high at insemination in 3 out of 5 animals, but the overall pattern of this steroid was inconsistent during the period studied. A high concentration of androgen was recorded in all the animals from day 2–5 before the onset of oestrus.


1976 ◽  
Vol 56 (1) ◽  
pp. 37-42 ◽  
Author(s):  
R. RAJAMAHENDRAN ◽  
P. C. LAGUË ◽  
R. D. BAKER

Progesterone levels were estimated by radioimmunoassay in blood samples obtained by venipuncture on the day of estrus and every alternate day until the onset of the next estrus in eight cycling dairy heifers. The mean level of progesterone was < 1 ng/ml during the first 2 days of the cycle, increased rapidly over the 4th–12th day period and reached a peak level value of 5.2 ± 1.1 ng/ml on day 14. Thereafter, the level declined rapidly to 2.6 ± 0.6 ng/ml on day 16 and then more gradually to 0.4 ± 0.1 ng/ml on day 21. In the second experiment, eight cycling heifers at diestrus were treated with gonadotrophin (2,000 IU PMSG or 1,000 IU PMSG + 1,000 IU HCG) followed 48 h later by 15 mg prostaglandin (PGF2α). Mid-ventral laparotomies were performed 4 days after the onset of estrus to observe ovarian activity. Progesterone levels were considerably higher in some animals and were slightly higher on the average after gonadotrophin treatments. The number of corpora lutea (CL) in these heifers ranged from 1 to 17. Progesterone levels of three heifers with 4–9 CL did not differ (P > 0.05) from those of three heifers with single CL. Two heifers each with 17 CL had peak progesterone levels of 38.4 and 27.8 ng/ml which were still high (9.6 and 26.5 ng/ml) by day 21. The remaining six heifers had low progesterone levels (< 1 ng/ml) by days 8–14, indicating premature regression of the CL. Thus, progesterone levels were not correlated with the number of CL.


2009 ◽  
Vol 21 (1) ◽  
pp. 101 ◽  
Author(s):  
O. A. Bogle ◽  
D. Ambati ◽  
R. P. Davis ◽  
G. P. Adams

The presence of an ovulation-inducing factor (OIF) in the seminal plasma of llamas and alpacas (reflex ovulators) and cattle (spontaneous ovulators) has been reported previously (Ratto MH et al. 2006 Theriogenology 66, 1102–1106). The presence of this protein in unrelated species supports the hypothesis that OIF is a conserved factor among species. The objectives of this study were to determine if OIF was present in equine and porcine seminal plasma, and whether the proportion of test animals (llamas) that ovulated in response to treatment with seminal plasma was related to dose. In Experiment 1, female llamas were assigned randomly to four groups (n = 8 or 9 per group) and treated intramuscularly with 1 mL llama seminal plasma (positive control), 3 mL equine seminal plasma, 3 mL porcine seminal plasma, or 2 mL saline (negative control). Ovulation and maximum corpus luteum diameter were compared using ultrasonography and confirmed with blood samples taken on Day 7 (Day 0 = day of treatment) to determine plasma progesterone concentration. The diameter of the preovulatory follicle at the time of treatment did not differ among groups. Equine seminal plasma induced ovulations in 3/8 (38%) llamas compared to 0/8 (0%) llamas treated with saline or porcine seminal plasma (P = 0.1). The proportion of females that ovulated was lower in the equine group (P < 0.01) compared with those animals treated with llama seminal plasma (9/9; 100%). Of the animals that ovulated, maximum CL diameter did not differ between llama and equine seminal plasma-treated groups (mean ± SEM; 11.1 ± 1.1, 11.5 ± 1.5, respectively). Similarly, progesterone concentrations were not different among llamas treated with llama seminal plasma or equine seminal plasma (mean ± SEM; 3.1 ± 0.4, 3.7 ± 1.2, respectively). The design of Experiment 2 was the same, but the dose of equine and porcine seminal plasma was increased to 8 mL and 10 mL, respectively. The proportion of females that ovulated was less (P < 0.05) in equine (2/9) and porcine (3/9) seminal plasma groups compared with the group treated with llama seminal plasma (9/9). There were no ovulations detected in llamas treated with saline (0/8). Although differences between equine, porcine, and negative control groups did not reach significance, results provide some evidence for the presence of OIF in equine and porcine seminal plasma. The effect of dose of equine and porcine seminal plasma is equivocal, suggesting that the concentration of OIF in the seminal plasma of these species may be very low and the optimal dose for inducing ovulation in test animals had not been reached. Research supported by the Natural Sciences and Engineering Council of Canada.


1972 ◽  
Vol 52 (1) ◽  
pp. 23-36 ◽  
Author(s):  
G. D. THORBURN ◽  
W. SCHNEIDER

SUMMARY Progesterone concentrations in the peripheral plasma of goats were measured by a protein-binding assay. The mean concentration was extremely low on the day of oestrus (0·2 ng/ml) and was not significantly different from that found in anoestrous or ovariectomized animals. The concentration increased to a maximum of 4 ng/ml on about day 10 of the 21-day cycle, and decreased rapidly during the last 3 days of the cycle. Plasma progesterone concentration during early pregnancy (2·5–3·5 ng/ml) was similar to the luteal phase value and remained steady from day 8 to day 60. Between days 60 and 70 there was a secondary increase in progesterone concentration which was maintained at this increased level (4·5–5·5 ng/ml) until just before parturition. In twin-bearing animals, the secondary increase was greater. Progesterone concentration decreased rapidly during the 1–2 days preceding parturition, but the concentration was still quite high on the day of parturition (1·25 ng/ml). The progesterone concentration in peripheral plasma was markedly increased during anaesthesia and the operation. After bilateral ovariectomy of the pregnant goat, peripheral progesterone concentration fell rapidly from 9 to 2·5 ng/ml during the first ½ h and then more slowly during the next 5–6 h. The animals aborted 36–48 h later. A consistent positive arterio—venous difference for progesterone was observed across the pregnant uterus in two unanaesthetized goats. These results indicate that the ovary is the main site of progesterone production in the pregnant goat and that production by the placenta is small and unlikely to influence the level of this hormone in the maternal circulation.


1993 ◽  
Vol 5 (1) ◽  
pp. 15 ◽  
Author(s):  
T Kojima ◽  
LA Hinds ◽  
WJ Muller ◽  
C O'Neill ◽  
CH Tyndale-Biscoe

The corpus luteum (CL) of the tammar is suppressed by lactation. Removal of the sucking pouch young induces reactivation of the CL which produces a peak in plasma progesterone concentration on Day 5, 6 or 7; reactivation of the embryo after diapause precedes by one day this transient peak of progesterone. This study examines progesterone production and secretion in vitro by the CL and the production of platelet activating factor (PAF) by the endometrium during this stage of pregnancy (Days 0 and 3-8). Blood samples were collected twice daily to determine for each animal (n = 28) at autopsy the relationship of PAF production to the day of the progesterone peak. Significant changes in basal plasma progesterone concentrations were used to define four groups according to the time the animals were killed: Group A, Day 0; Group B, other animals showing no significant change; Group C, peripheral progesterone concentration increasing; Group D, peripheral progesterone concentration decreasing after the peak. At autopsy on successive days, blood samples were taken from the heart, caudal vein and uterine branch of the ovarian vein, and CL and endometria were prepared for explant culture. Progesterone contents of pre- and post-incubation luteal tissues and of medium were determined at 4, 12 and 24 h to estimate production and secretion rates. The values for all progesterone parameters from animals in Group C were significantly higher than in the other groups. It is concluded that the progesterone peak results from a change in rate of production and secretion of progesterone by the CL, one day before the peak in peripheral plasma, and that this change could provide the first signal to the uterus. Endometrium was incubated for 24 h and the medium assayed for PAF. High concentrations of PAF were detected in half the animals in Groups B and C, that is, before or at the time progesterone was increasing. This is the first measurement of PAF in any marsupial and the first demonstration of the release of PAF by the endometrium. The detection of PAF provides a candidate for an endometrial signal that is responsive to the rising progesterone concentration in the utero-ovarian vein draining the CL-bearing ovary and that may stimulate reactivation of the blastocyst.


Rangifer ◽  
1991 ◽  
Vol 11 (2) ◽  
pp. 13 ◽  
Author(s):  
Erik Ropstad ◽  
Dag Lenvik

A total of 126 reindeer of about 7 months of age, were isolated from a flock at the end of the breeding season. The animals were treated either with 12.5 mg prostaglandin F2alpha (n = 41) or 0.25 mg cloprostenol (n = 50). Thirty-five animals were left untreated. Blood samples were collected before treatment and 2 Vi days later and the plasma progesterone concentrations were determined. A significant fall in progesterone concentration was seen in both treatment groups. A large proportion of animals responded to treatment with cloprostenol than with prostaglandin F2alpha. It was concluded that prostaglandins can be used to induce luteolysis in reindeer.


1974 ◽  
Vol 27 (6) ◽  
pp. 659 ◽  
Author(s):  
AR Gleeson ◽  
GD Thorburn

A competitive protein-binding technique was used to measure progesterone concentrations in the peripheral plasma of pregnant ewes. Neither haemolysis of blood nor thawing of plasma samples affected plasma progesterone concentration. Blood samples should be chilled immediately upon collection but subsequent to centrifugation immediate chilling of the plasma samples is not critical. No consistent diurnal variation in progesterone concentrations was evident but there was large apparently random day-to-day variation in progesterone concentrations for any ewe. Although a significant positive correlation was found between endogenous progesterone and corticosteroid concentrations, the present study failed to correlate experimentally elevated plasma corticosteroid concentrations with progesterone concentrations. Progesterone concentrations varied greatly between ewes at the same stage of pregnancy.


1987 ◽  
Vol 45 (2) ◽  
pp. 205-209 ◽  
Author(s):  
C. A. Morris ◽  
A. M. Day ◽  
A. J. Peterson

ABSTRACTPlasma progesterone concentrations were measured over two collection periods from two groups of mature non-pregnant cows involved in a twin-breeding experiment. One group (T) consisted of cows obtained from private herds after having produced at least two sets of twins each; the other was a control group of similar ages and breeds. Yearling heifers from the same breeding experiment were also included. The mean progesterone concentration from cows in the T group was proportionally 0·83 of the value in control cows and the cow group effects were consistent in direction for samples obtained after single or double ovulations. Results were also consistent in early oestrous cycle (days 3 to 7, oestrus = day 0), mid cycle (days 8 to 13) but not late cycle (days 14 to 18). Concentrations were significantly higher in yearling heifers than in control cows. There was a trend for higher progesterone concentrations after double than after single ovulations assessed by rectal palpation, but differences were not significant.


1973 ◽  
Vol 58 (2) ◽  
pp. 219-225 ◽  
Author(s):  
K. P. McNATTY ◽  
K. J. A. REVFEIM ◽  
A. YOUNG

SUMMARY Progesterone concentrations in peripheral plasma were measured once daily during one oestrous cycle in each of eight sheep. In addition, on days 4–5, 8–9, 12–13 and 15–16 of the oestrous cycle, blood samples were collected at 30-min intervals throughout each 24-h period. A total of three ewes was sampled in each 24-h period and the same three animals were not bled again for at least 1 week. Plasma progesterone concentrations in all the ewes fluctuated considerably throughout each 24-h period. The within-sheep within-day variations observed in peripheral progesterone concentrations were compared with the between-sheep within-day variations and the within-sheep between-day variations previously reported. It is concluded that these previously reported variations in peripheral plasma progesterone concentration could be attributed to within-day variations in each animal. On days 8–9 and 12–13 of the oestrous cycle there were significantly higher concentrations of progesterone in plasma during the hours of daylight than during the hours of darkness. In contrast, progesterone concentrations on days 4–5 and 15–16 were not found to be significantly different between the hours of daylight and darkness. These results suggest that diurnal changes in peripheral plasma progesterone concentration occur during the luteal phase of the ovine oestrous cycle.


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