scholarly journals The effect of medroxyprogesterone acetate on pregnancy rates in reindeer calves (Rangifer tarandus)

Rangifer ◽  
1993 ◽  
Vol 13 (4) ◽  
pp. 163
Author(s):  
Erik Ropstad ◽  
Gaute Helland ◽  
Helge Hansen ◽  
Dag Lenvik ◽  
Eva Tangen Solberg
Keyword(s):  
Body Weight ◽  
Medroxyprogesterone Acetate ◽  
Rangifer Tarandus ◽  
Single Injection ◽  
Lower Plasma ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Pregnant Females ◽  
Body Weight Increase ◽  
The Mean

In September 1990, a total of 69 calves with a minimum body weight of 46 kg were allocated into two groups, one treated with a single injection of 75 mg medroxyprogesterone acetate (N = 35), the other serving as control (N=34). Blood samples were collected for progesterone analysis in December 1990 and 1991. Udder palpation was performed in July and September 1990. Treated animals had significantly lower plasma progesterone levels in December 1990. The pregnancy rate as determined by udder palpation was 16.7% for treated animals and 48.3% for controls (P<0.01). All animals which were found to be pregnant had high progesterone levels (>5 ng/ml) the following winter. The mean body weight increase was 5.1 kg lower in females which kept their calves until September than in barren females (P<0.05). More than 50% of the pregnant females lost their calves during the summer.

Pattern of plasma progesterone, oestradiol-17β, luteinizing hormone and androgen in non-pregnant buffalo (Bubalus bubalis)

1982 ◽  
Vol 100 (2) ◽  
pp. 279-284 ◽  
Author(s):  
R. C. Arora ◽  
R. S. Pandey
Keyword(s):  
Luteinizing Hormone ◽  
Peak Level ◽  
Systemic Circulation ◽  
Bubalus Bubalis ◽  
High Concentration ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Androgen Level ◽  
The Mean ◽  
Low Levels

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.

The Small Mammals of Little Nourlangie Rock, NT. V. The Effects of Fire

1981 ◽  
Vol 8 (3) ◽  
pp. 515 ◽  
Author(s):  
RJ Begg ◽  
KC Martin ◽  
NF Price
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Small Mammals ◽  
Pregnant Females ◽  
Preferred Habitat ◽  
Closed Forest ◽  
The Mean ◽  
Fuel Characteristics ◽  
Release Program

Following a capture-mark-release program (February 1977-June 1979) on Dasyurus hallucatus, Antechinus bilarni, Zyzomys argurus and Zyzomys woodwardi, the study area was burnt to determine the effects of fire on these species. The area was described in terms of fuel characteristics and details of the fire were recorded. Post-fire trapping began July 1979 and continued until July 1980 (15,600 trap-nights). A. bilarni was the only species to suffer an increased mortality immediately after the fire, but the number of animals known to be alive declined over the year following the fire, for all species except D. hallucatus. The fire affected reproduction in all four species, but in different ways. Breeding in D. hallucatus was delayed by 1 month, and the mean number of young leaving the pouch per female was lower than before the fire. A higher number of resident females kept recruitment up. Litter size in A. bilarni was not affected, but a reduced number of resident females meant that recruitment was halved. Zyzomys argurus and Z. woodwardi showed few lactating and pregnant females in July-August following the fire, and the numbers of juveniles were lower than in the previous two years. Following the fire, no detectable differences in body weight were recorded, but all species except D. hallucatus changed their preferred habitat, moving to the Scree Slope. Z. woodwardi was most affected, and moved from the Closed Forest.

PLASMA PROGESTERONE LEVELS IN CYCLING AND GONADOTROPHIN–PROSTAGLANDIN-TREATED HEIFERS

1976 ◽  
Vol 56 (1) ◽  
pp. 37-42 ◽  
Author(s):  
R. RAJAMAHENDRAN ◽  
P. C. LAGUË ◽  
R. D. BAKER
Keyword(s):  
Peak Level ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Dairy Heifers ◽  
The Mean

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.

Pre-puberal plasma luteinizing hormone concentrations and progesterone concentrations during the oestrous cycle and early pregnancy in Galway and Fingalway female lambs

1979 ◽  
Vol 28 (1) ◽  
pp. 1-12 ◽  
Author(s):  
J. F. Quirke ◽  
J. P. Gosling
Keyword(s):  
Luteinizing Hormone ◽  
Young Female ◽  
Oestrous Cycle ◽  
Plasma Progesterone ◽  
Pregnant Females ◽  
Breed Differences ◽  
The Mean ◽  
Ad Libitum ◽  
Maintenance Requirements ◽  
Female Sheep

ABSTRACTTwenty-four young female sheep, 12 Galways and 12 Fingalways, were used to study the effects of breed and level of nutrition on pre-puberal plasma luteinizing hormone and progesterone concentrations throughout the oestrous cycle and during the first 35 days of pregnancy. The sheep were spring-born and were housed at the end of July when they weighed approx. 34 kg. Equal numbers of animals from each breed were fed on a concentrate diet either ad libitum or at a restricted level that was slightly above their estimated maintenance requirements. The Fingalways reached puberty 1 month earlier than the Galways (11 October ±4 days v. 10 November ±5 days). The restricted animals tended (P < 0·10) to reach puberty later than those fed ad libitum (1 November ±5 days v. 20 October ±4 days). Breed differences in the mean level of plasma progesterone on any day of the oestrous cycle were not significant. The mean daily plasma progesterone concentration was similar for the animals on the two planes of nutrition throughout the cycle, with the exception of day 11 when those fed ad libitum had a significantly higher level (P < 0·01). Plasma progesterone levels in the pregnant females between 5 and 35 days post mating were generally higher in Fingalways than in Galways and were not influenced by plane of nutrition. Plasma luteinizing hormone levels tended to be higher, during the 7 weeks before puberty, in Fingalways than in Galways and in animals fed ad libitum than in those on the restricted level of feeding.

THE INFLUENCE OF GILT AGE ON THE ENDOCRINE AND OVULATORY RESPONSE TO DIFFERENT DOSES OF ESTRADIOL BENZOATE

1988 ◽  
Vol 68 (3) ◽  
pp. 979-982 ◽  
Author(s):  
R. N. KIRKWOOD ◽  
F. X. AHERNE
Keyword(s):  
Body Weight ◽  
Luteinizing Hormone ◽  
Key Words ◽  
Jugular Vein ◽  
Estradiol Benzoate ◽  
Blood Samples ◽  
Estrous Cyclicity ◽  
The Mean ◽  
Different Doses ◽  
Phasic Release

Fifty-five prepubertal Yorkshire × Landrace gilts were randomly assigned to one of six treatments involving the injection (i.m.) of estradiol benzoate (EB) at either 10 or 20 μg kg−1 body weight at gilt ages of 130, 150 or 170 d. Blood samples were taken by jugular vein puncture at 0, 24, and 36 h, and then at 6-h intervals until 84 h, after injection and assayed for plasma luteinizing hormone (LH) concentrations. The mean magnitude of the EB-induced LH peak was 6.1 ± 0.2 ng mL−1, and was not affected by treatment. Fifty-six percent of gilts ovulated in response to EB injection, and 34% had a subsequent ovulation. The initial ovulation rate was unaffected by EB dose, but was higher (P < 0.05) in 170 d (9.9 ± 1.0) compared to younger gilts (4.2 ± 1.1 and 5.5 ± 1.1 for 130-dand 150-d gilts, respectively). Subsequent ovulation rates were unaffected by treatment. It is concluded that EB treatment will usually induce a phasic release of LH from prepubertal gilts, but this release is not necessarily accompanied by normal estrous cyclicity. Key words: Estradiol, gilts, ovulation

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
Keyword(s):  
Live Weight ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Treatment Interaction ◽  
The Mean

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.

scholarly journals The use of Cloprostenol and prostaglandin F2alpha to induce luteolysis in reindeer calves (Rangifer tarandus)

Rangifer ◽  
1991 ◽  
Vol 11 (2) ◽  
pp. 13 ◽  
Author(s):  
Erik Ropstad ◽  
Dag Lenvik
Keyword(s):  
Breeding Season ◽  
Rangifer Tarandus ◽  
Prostaglandin F2alpha ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Treatment Groups ◽  
Significant Fall

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.

A note on the effect of contact with male goats on occurrence of puberty in female goat kids

1984 ◽  
Vol 38 (1) ◽  
pp. 141-144 ◽  
Author(s):  
E. A. Amoah ◽  
M. J. Bryant
Keyword(s):  
Plasma Progesterone ◽  
Blood Samples ◽  
The Mean ◽  
October 17

ABSTRACTTwelve British Saanen female kids were exposed to male goats for 1 h daily on 29 July (Ml), 12 on 12 August (M2) and 12 on 27 October (M3), when the kids were, on average, (± s.d.) 136·4 (± 12·2), 150·2 (± 12·8) and 225·4 (± 3·5) days of age, respectively. Blood samples were collected to determine plasma progesterone concentrations from 17 July onwards. By 27 October, 11 and 12 kids from treatments Ml and M2 had attained puberty, compared with no kids from treatment M3. Ten kids from treatment M3 attained puberty after male introduction. The mean ages and dates at puberty for treatments Ml, M2 and M3, respectively, were as follows: 205·5, 215·3 and 233·0 days (P < 0·001); and 7 October, 17 October and 3 November (P < 0·001). The mean reaction interval to male introduction for treatments Ml, M2 and M3 was 69, 66 and 7 days (P < 0·001), respectively. The variances for the date of attainment of puberty showed differences in the degree of synchronization of the event between all three treatments.

THE EFFECT OF STRESS AND ADRENALECTOMY ON THE RESPONSE TO DICUMAROL IN RATS

1958 ◽  
Vol 36 (1) ◽  
pp. 51-62
Author(s):  
G. J. Mogenson ◽  
L. M. Fisher ◽  
L. B. Jaques
Keyword(s):  
Body Weight ◽  
Prothrombin Time ◽  
Dose Level ◽  
Ether Anesthesia ◽  
Blood Samples ◽  
Mean Values ◽  
Tail Vein ◽  
The Mean ◽  
Dose Levels ◽  
Adrenalectomized Rats

The prothrombin time was followed in a large number of rats receiving daily doses of dicumarol. Prothrombin times, using the Schwager–Jaques method, were determined on blood samples obtained from the tail vein. It was found that rats, like rabbits, showed a wide variation in their response to dicumarol at dose levels of 10 and 20 mg./kg. body weight per day but, unlike rabbits, they seemed to develop a tolerance to the drug. This began after a peak prothrombin time was reached and occurred later in rats having a higher prothrombin time, or receiving the higher dose of the drug. Stress, in the form of electroshock or sound-induced seizures, increased the variability of the prothrombin time and significantly increased the mean values with 20 mg./kg. dicumarol. These changes persisted in some rats for at least 48 hours. They were prevented by ether anesthesia. Adrenalectomized rats fed dicumarol showed a marked increase in prothrombin time, did not develop tolerance to the drug after a few days, and died of hemorrhage. An analysis of blood samples obtained by cardiac puncture from adrenalectomized, sham-operated, and normal rats fed dicumarol at a dose level of 10 mg./kg. body weight for 5 days showed that values for the Quick one-stage prothrombin times of the adrenalectomized group were elevated significantly above those of the sham-operated and normal groups. No significant differences, however, were noted in the values for the two-stage tests for prothrombin, hematocrit, or plasma dicumarol levels of these animals.

Oestrus in relation to peak oestradiol levels in ovariectomized Galloway cows

2001 ◽  
Vol 72 (2) ◽  
pp. 401-405
Author(s):  
A. O. Darwash ◽  
G. E. Lamming ◽  
L. M. Hicking
Keyword(s):  
Luteal Phase ◽  
Intramuscular Injection ◽  
High Plasma ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Measured Dose ◽  
Oestradiol Benzoate ◽  
The Mean ◽  
Plasma Oestradiol ◽  
Follicular Activity

AbstractThe objective of the present study was to characterize the variation in oestrous behaviour among ovariectomized cows in response to a measured dose of oestradiol benzoate (OB) . In study 1, nine ovariectomized Galloway cows, approximately 10 years old, were challenged with an intramuscular injection of either 0·25, 0·5 or 1·0 mg of OB. Following this, 0·5 mg OB was chosen as the appropriate dose required to induce oestrous behaviour in ovariectomized Galloway cows. In study 2, nine cows injected with 0·5 mg OB were monitored for oestrous behaviour using KAMAR® heat mount detectors. Blood samples for plasma oestradiol-17β (E2) assay were taken every 4 h between 0 to 72 h and once at 96 h, following OB administration. The plasma E2 concentrations between 0 to 96 h following OB administration differed significantly ( P < 0·001) among cows. The interval to peak E2 concentrations averaged 17·42 (s.e. 2·21) h and the mean peak E2 concentration was 5·86 (s.e. 0·57) ng/l. The mean interval from OB administration until onset of mounting activity was 24·57 (s.e.2·38) h and the duration of oestrus averaged 10·5 (s.e. 1·99) h . In all cows, mounting activity occurred following peak E2 concentrations after an average interval of 7·73 (s.e. 1·84) h. There was no significant association between peak E2 concentrations and the interval to onset of mounting activity or its duration. Since the variation among Galloway cows in the manifestation of behavioural oestrus was independent of systemic E2 concentrations, it implies that there are inherent differences between individuals in the sensitivity of the hypothalamus to physiological E2 thresholds. This may help to explain the incidence of silent ovulation in some animals and the occurrence of overt oestrus associated with follicular activity during the luteal phase of the cycle or during the various stages of pregnancy, in the presence of high plasma progesterone concentrations.

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