Effect of vehicle and route of administration of letrozole on ovarian function in a bovine model

2014 ◽  
Vol 26 (8) ◽  
pp. 1198 ◽  
Author(s):  
M. J. Yapura ◽  
R. J. Mapletoft ◽  
R. A. Pierson ◽  
J. Singh ◽  
G. P. Adams
Keyword(s):  
Corpus Luteum ◽  
Ovarian Function ◽  
Treatment Protocol ◽  
Route Of Administration ◽  
Control Group ◽  
Beef Heifers ◽  
Plasma Progesterone ◽  
Treatment Groups ◽  
Sexually Mature ◽  
Plasma Oestradiol

The objective of this study was to determine the effects of vehicle and route of administration of letrozole on ovarian function in sexually mature beef heifers. On Day 3 (Day 0 = ovulation), heifers were assigned randomly to four treatment groups and given 1 mg kg–1 letrozole intravenously (iv, n = 10) or intramuscularly (im, n = 10) or given a placebo iv (control iv, n = 5) or im (control im, n = 5). The interwave interval was longer in heifers treated with letrozole im than in im and iv controls (11.7 ± 0.30 vs 9.5 ± 0.50 and 10 ± 0.43, respectively; P < 0.05). Corpus luteum diameter profiles and plasma progesterone concentrations were greater (P < 0.03 and P < 0.05, respectively) in heifers treated with letrozole im compared with control im. Plasma oestradiol concentrations were lower in both letrozole-treated groups compared with controls (P ≤ 0.03). Plasma LH concentrations tended to be elevated at the time of wave emergence in heifers treated with letrozole im compared with other groups (group-by-day interaction, P = 0.06) and plasma FSH concentrations tended to be greater (P < 0.09) in heifers treated with letrozole by either route compared with a single control group. We conclude that intramuscular administration of letrozole in oil is a feasible route and vehicle for the development of a letrozole-based treatment protocol for herd synchronisation in cattle.

A note on the concentrations of plasma oestradiol-17β and progesterone around the time of puberty in heifers

1984 ◽  
Vol 39 (1) ◽  
pp. 137-140 ◽  
Author(s):  
R. G. Glencross
Keyword(s):  
Life Span ◽  
Corpus Luteum ◽  
Cervical Mucus ◽  
Plasma Progesterone ◽  
Induced Ovulation ◽  
Normal Life ◽  
Short Period ◽  
Before And After ◽  
Normal Life Span ◽  
Plasma Oestradiol

ABSTRACTIn heifers, plasma progesterone levels were low (<0·3μg/l) from the 59th to about the 15th day before puberty (defined as the day when oestrus was first detectable by the fern pattern of dried cervical mucus). Plasma oestradiol-17β levels varied randomly within the range 1 to 4 ng/l over the same period, but then showed three peaks of about 6, 9 and 4 ng/l, respectively 8 days before puberty, on the day of puberty and 4 days later. The pre-pubertal oestradiol-17p peak was followed by a short period of elevated progesterone levels. Whether this oestradiol-17β peak induced ovulation is uncertain; it is however clear that a corpus luteum of normal life-span was not formed. The oestradiol-17β peaks on the day of puberty and 4 days later, when progesterone levels were rising rapidly, were typical both in magnitude and duration of those occurring before and after ovulation in post-pubertal oestrous cycles.

Concentrations of plasma hormones in relation to placental retention in Karan Swiss cows during and after induction of parturition with dexamethasone and stilboestrol dipropionate

1985 ◽  
Vol 40 (1) ◽  
pp. 1-9 ◽  
Author(s):  
B. S. Prakash ◽  
M. L. Madan
Keyword(s):  
Drug Administration ◽  
Sampling Period ◽  
Significant Drop ◽  
Veterinary Clinic ◽  
Plasma Progesterone ◽  
Treatment Groups ◽  
Group A ◽  
Plasma Hormones ◽  
Group B ◽  
Plasma Oestradiol

ABSTRACTFive Karan Swiss cows were allowed to calve spontaneously and served as controls (Group A), while another 10 were induced to calve about 1 month prior to expected term using either 25 mg dexamethasone alone (Group B) or 25 mg dexamethasone in combination with 25 mg stilboestrol dipropionate (Group C). Blood samples were collected prior to, and for 50 days following, parturition for subsequent hormone analysis, and observations were made on the occurrence of retained placentae.Parturition was successfully induced in all treated cows within 72 h of drug administration. Placental membranes were retained for 24 h in all treated animals and were manually removed in the farm veterinary clinic. No incidence of placental retention occurred in control cows.Mean plasma oestradiol-17β in control cows showed a gradual rise from days 30 to 5 pre partum, followed by a sharp increase to peak value 1 day before calving. The rise in mean oestradiol-17β levels in the 2 days before parturition in controls was significantly greater than that recorded for the treated animals. A precipitous drop in plasma oestradiol-17β level occurred following parturition in all groups, with the levels staying low for the rest of the sampling period. Drug administration to animals in groups B and C resulted in a rapid and significant drop in plasma progesterone concentrations to a level similar to that for control animals at parturition. Subsequently, the plasma progesterone remained low in all treatment groups. Mean plasma cortisol levels showed a significant but transient increase at calving in control cows, but were suppressed for at least 48 h following drug administration in treated cows before exhibiting a rebound phenomenon to reach high values after calving.It is concluded that for normal placental expulsion, oestradiol-17β levels are more critical than progesterone, and that the rise in oestradiol-17β and fall in progesterone levels pre partum must be gradual.

scholarly journals Histological and hormonal studies of calabash chalk on ovarian function in adult female wistar rats

2017 ◽  
Vol 34 (03) ◽  
pp. 173-177
Author(s):  
A. Oyewopo ◽  
K. Obasi ◽  
K. Anumudu ◽  
E. Yawson
Keyword(s):  
Body Weight ◽  
Adult Female ◽  
Wistar Rats ◽  
Ovarian Function ◽  
Female Rats ◽  
Control Group ◽  
Treatment Groups ◽  
Female Wistar Rats ◽  
Group A ◽  
Group B

Abstract Introduction: Calabash chalk is a naturally occurring mineral, chiefly composed of fossilized sea shells. It is prepared from clay and mud mixed with other ingredients, including lead, arsenic, sand and wood ash. Clay consumption is correlated with pregnancy, and also to eliminate morning sickness in women. The aim of this study is to evaluate the effects of calabash chalk on the ovarian function in adult female Wistar rats. Methods: Eighteen (18) adult female Wistar rats. Group A served as the control group, group B received 40 mg/kg body weight of Non-salted calabash chalk while group C received 40 mg/kg body weight of Salted calabash chalk for 14 days. On day 15, the animals were sacrificed for histological and biochemical examination. Results: Results showed a significant (P< 0.05) reduction in follicle stimulating hormone (FSH) levels of the treatment groups when compared with the control group and an increase in luteinizing hormone (LH) levels of the treatment groups when compared with the control group. Histological examination of the ovaries showed severe deterioration of the ovarian follicles, necrosis and follicular atresia. Conclusion: Calabash chalk is toxic to ovarian function. These alterations have been shown to be the leading cause ofinfertility in female rats. Hence, proper monitoring, education, and regulation of the product is needed.

10 EFFECT OF ESTRADIOL BENZOATE OR hCG ON DAY 22 AFTER TIMED ARTIFICIAL INSEMINATION ON THE CORPUS LUTEUM SIZE, PROGESTERONE CONCENTRATION, AND PREGNANCY RATE IN RESYNCHRONIZED BEEF HEIFERS

2016 ◽  
Vol 28 (2) ◽  
pp. 134
Author(s):  
J. B. S. Borges ◽  
H. L. D. Neri ◽  
M. R. Almeida ◽  
E. P. Silva ◽  
A. Bilha
Keyword(s):  
Corpus Luteum ◽  
Pregnancy Rate ◽  
Body Condition ◽  
Body Condition Score ◽  
Pregnancy Rates ◽  
Control Group ◽  
Beef Heifers ◽  
Pregnancy Diagnosis ◽  
Condition Score ◽  
And Control

This study aimed to compare the effects of 2 inducers of new follicular wave [oestradiol benzoate (EB) or hCG] administrated at onset of resynchronization protocols initiated 22 days after the first timed AI (TAI) of beef heifers. We evaluated the effect of treatments on corpus luteum (CL) development, serum progesterone (P4) concentrations, and pregnancy rates. A total of 467 grazing Brangus heifers, with 24- to 26-months, 320 ± 10 kg of body weight, and 3.2 ± 0.5 body condition score, were utilised. The resynchronization protocol began 22 days after the first TAI (Day 22). Heifers were randomly allocated into 1 of 3 groups: EB (n = 199), hCG (n = 101), or control untreated (n = 167). The EB- and hCG-treated heifers received an intravaginal P4 device (Procliclar, 0.75 g of P4; Hertape, Brazil) and an IM treatment with 1 mg of EB (Benzoato HC, Hertape) or 1000 IU of hCG (Vetecor 5000, Hertape), respectively. On Day 30, P4 device was removed, and the pregnancy diagnosis was performed. At this time heifers had the CL area (cm2) determined by ultrasound and seric P4 concentration evaluated by chemiluminescence assay. The assay sensitivity was 0.1 ng mL–1, and the intra- and interassay coefficients of variation were 7.9 and 10.6%, respectively. Nonpregnant heifers after the first TAI (EB = 97, hCG = 36) received intramuscularly 150 μg of sodium cloprostenol (Veteglan Luteolítico, Hertape) and 1 mg of oestradiol cypionate (Cipionato HC, Hertape). The second TAI was performed 48 to 52 h after the P4 device removal. On Day 62, heifers were submitted to a second pregnancy diagnosis. No effect of the body condition score (P = 0.28) was observed on the first and second pregnancy per AI. Pregnancy rates after the first TAI were higher (P = 0.03) on hCG-treated heifers (64.4%) than EB (51.3%) or the control group (58.7%). The EB group determined greater (P = 0.04) pregnancy rate after the second TAI (49.5%) than the hCG group (22.2%). The cumulative pregnancy rates were similar (P = 0.46) between groups [EB (72.4%) and hCG (68.3%)]; however, both were greater (P < 0.05) than the control group (58.6%). Heifers treated with hCG (3.42 ± 0.76) presented greater CL area at Day 30 (P < 0.05) than the EB (2.44 ± 0.57) and control (2.61 ± 0.61) groups. The treatment with hCG 22 days after TAI determined greater (12.43 ± 3.48; P < 0.05) serum P4 concentrations on Day 30 than the EB (6.92 ± 3.04) and control (7.29 ± 2.45) groups. Therefore, the use of hCG at the beginning of resynchronization protocol 22 days after the TAI increased pregnancy rate following the first TAI. However, the use of 1 mg of EB determined greater pregnancy rate after the second TAI, and no detrimental effects on CL development, P4 concentration, and on first TAI pre-established pregnancy.

Impact of bypass fat and mineral supplementation peripartum on plasma profile of steroid hormones PGFM and postpartum fertility in Jaffarabadi buffaloes

2019 ◽  
Author(s):  
A.J. Dhami ◽  
K.B. Vala ◽  
F.S. Kavani ◽  
S.C. Parmar ◽  
R.J. Raval ◽  
...  
Keyword(s):  
Steroid Hormones ◽  
Post Partum ◽  
Control Group ◽  
Plasma Progesterone ◽  
Mean Values ◽  
Treatment Groups ◽  
Uterine Involution ◽  
Postpartum Estrus ◽  
Plasma Profile ◽  
Bypass Fat

Advanced pregnant Jaffarabadi buffaloes (n=40) of 2-4 parity selected on an organized farm were divided equally into control (routine farm feeding-RFF) and treatment/nutrients supplementation (RFF + bypass fat @ 150-200 g/h/d and ASMM @ 50 g/h/d) groups and were studied from 6 wks prepartum to 8 wks postpartum for plasma profile of steroid hormones and PGF2a metabolites on days -45, -30, -7, 0, +7, +15, +30, +45 and +60 peripartum as well as for puerperal events and postpartum fertility. Half of the buffaloes in both the groups also received parenteral microminerals (Inj. Stimvet 5 ml i/m) twice, 45 days before and on the day of calving. Again half of them were treated with ecbolic (Exapar) 2 boli bid for first 4 days postpartum. The mean plasma progesterone values were maximum (>4 ng/ml) on day 45 prepartum, which declined significantly (p less than 0.01) on day 7 prepartum reached to the basal levels (1 ng/ml) on the day of calving, remained basal till day 15, and thereafter showed a rising trend on days 30, 45 and 60 postpartum. The oestradiol-17b values were at its peak on the day of calving (p less tahn 0.01), showed a rapid fall by day 7 postpartum and remained low till recrudesce of follicular activity around day 45 and 60 postpartum. The levels of cortisol were significantly higher on the day of parturition as compared to values on day 7 pre- and post-partum. The plasma concentration of PGFM was low on day 45 prepartum, which increased gradually and significantly by almost 10-folds to reach peak values on the day of calving in both control and treatment groups and then declined gradually and significantly till day 45 postpartum. The rise was little more in nutrients supplemented group with higher mean values at most intervals peripartum than in control group. The periods for uterine involution, first postpartum estrus, and days open were significantly shorter with higher conception rate in nutrient supplemented group. It is concluded that the peripartum nutrient supplementation in Jaffarabadi buffaloes is beneficial and has positive effect on the postpartum fertility and plasma progesterone and PGFM profile.

scholarly journals Cefacetrile and Rifaximin association might improve first service conception rate and reduce the number of services per conception in cows with clinical endometritis

2021 ◽  
Vol 53 (3) ◽  
Author(s):  
Saleh Boudelal ◽  
Mounir Adnane ◽  
Abdelatif Niar
Keyword(s):  
Clinical Cure ◽  
Clinical Cure Rate ◽  
Treatment Protocol ◽  
Conception Rate ◽  
Control Group ◽  
Ovarian Activity ◽  
Cure Rate ◽  
Treatment Groups ◽  
Service Conception ◽  
The Difference

Clinical endometritis (CE) is a serious disease leading to poor reproductive performances in lactating dairy cows, thus diminishing farm profitability. To preserve optimum reproductive efficiency, various strategies and therapeutic approaches have been proposed to manage cows with CE, often with contradictory results. Thus, investigating new paths to CE treatment is economically important. The aim of the present study was to test the efficacy of three therapeutic protocols on the clinical cure rate of CE, and improvement of reproductive performance. Cows with CE (n=42), 21–38 days in milk (DIM), were assigned to three treatment groups: PGF: cows (n=19) were treated systemically with two doses of d-cloprostenol, a PGF2α analogue, at 14-days intervals; CEFAX: cows (n=10) received an intrauterine infusion of the combined antibiotics Cefacetrile and Rifaximin; and NAX: cows (n=13) received systemic treatment with Ceftiofur crystalline free acid (CCFA). A control group included cows (n=36) free from CE (healthy group: HE). All cows were clinically re-examined after the end of the treatment protocol. The clinical cure rate was 73.7%, 80% and 69.2% in PGF, CEFAX, and NAX groups, respectively (P&gt;0.05). The HE group had a significantly shorter calving to first service interval compared to CEFAX and PGF groups (P&lt;0.05), however the difference was not significant with NAX group. The mean calving to fertilizing service interval (CFI) was slightly higher in all three treatment groups compared to the HE group, however the difference was not significant (P&gt;0.05). CEFAX protocol resulted in shorter but not statistically significant CFI, compared to the PGF and NAX protocols. Services per conception rate were slightly lower (1.7) in the CEFAX group compared to HE (1.75), PGF (1.84) and NAX (2.23) groups, however these differences were not significant. First service conception rate and conception rate at 105 DIM did not differ statistically between the treatment groups. While the difference was not significant, CEFAX protocol had slightly better cure rate for CE, reducing the number of services per conception and boosting the resumption of ovarian activity after calving. Validating these finding on a larger herd size will improve the accuracy of these findings.

176 EFFECTS OF VEHICLE AND ROUTE OF ADMINISTRATION OF LETROZOLE ON OVARIAN FUNCTION IN CATTLE

2011 ◽  
Vol 23 (1) ◽  
pp. 190 ◽  
Author(s):  
M. J. Yapura ◽  
R. J. Mapletoft ◽  
J. Singh ◽  
R. A. Pierson ◽  
D. Rogan ◽  
...  
Keyword(s):  
Aromatase Inhibitor ◽  
Benzyl Alcohol ◽  
Canola Oil ◽  
Ovarian Function ◽  
Transvaginal Ultrasound ◽  
Route Of Administration ◽  
Series Data ◽  
Dominant Follicle ◽  
Plasma Progesterone ◽  
Follicular Wave

Treatment with letrozole, a non-steroidal aromatase inhibitor, has been associated with elevated mean plasma LH concentrations, a prolonged period of dominance of the extant dominant follicle, and delayed emergence of the next follicular wave in cattle. As well, a luteotrophic effect was hypothesised by the observation that CL diameter was increased in heifers given 250 μg kg–1 of letrozole divided in a 3-day regimen. The objective of the present study was to determine the effects of vehicle and route of administration of letrozole on ovarian function in sexually mature beef heifers. Ovarian function was synchronized among heifers using transvaginal ultrasound-guided follicular ablation followed by a luteolytic dose of PGF b.i.d. 4 days later. The ovaries were subsequently examined daily by transrectal ultrasonography until ovulation was detected. On Day 3 (Day 0 = ovulation), heifers were assigned randomly to 4 treatment groups and given letrozole at a dose of 1 mg kg–1 intravenously (i.v. in benzyl alcohol, n = 10) or intramuscularly (i.m. in benzyl alcohol plus canola oil 1:1 v/v, n = 10), or given a placebo (i.v. in benzyl alcohol, n = 5) or (i.m. in benzyl alcohol plus canola oil 1:1 v/v, n = 5). The ovaries were monitored daily by ultrasonography, and blood samples collected twice daily by jugular venipuncture from pre-treatment to post-treatment ovulations. Comparisons among groups were made by 1-way ANOVA for single-point measurements and by ANOVA for repeated measures for time-series data. The interovulatory interval did not differ among groups, nor did the day-to-day diameter profile of the dominant follicle of wave 1 (first follicular wave after ovulation). However, the interval between emergence of waves 1 and 2 was longer in heifers treated with letrozole i.m. (11.7 ± 0.3 days) than in controls (10 ± 0.4 and 9.5 ± 0.5 days for i.v. and i.m. controls, respectively; P < 0.05), and intermediate in heifers given letrozole i.v. (10.6 ± 0.30 days). The day-to-day diameter profile of the corpus luteum was greater (P < 0.05), and plasma progesterone concentrations tended to be greater (P < 0.06) in heifers treated i.m. with letrozole v. placebo. Plasma LH concentrations did not differ among groups, whereas plasma FSH concentrations were greater (P < 0.02) in heifers treated i.v. with letrozole v. placebo. In summary, letrozole dissolved in benzyl alcohol and given intravenously at a dose of 1 mg kg–1 on Day 3 did not alter ovarian function in cattle, but the same dose given i.m. in canola oil vehicle resulted in a longer inter-wave interval, a greater CL diameter profile, and greater plasma progesterone concentrations. We conclude that i.m. letrozole in oil is a feasible route of administration and vehicle for the development of an aromatase inhibitor-based treatment for herd synchronization in cattle. Research supported by the Natural Sciences and Engineering Research Council of Canada, Canadian Institutes for Health Research, and Bioniche Life Science Inc.

The effect of GnRH analogue (buserelin) treatment on day 12 post mating on ovarian structure and plasma progesterone and oestradiol concentration in ewes

1996 ◽  
Vol 63 (3) ◽  
pp. 407-412 ◽  
Author(s):  
N. F. G. Beck ◽  
M. Jones ◽  
B. Davies ◽  
G. E. Mann ◽  
A. R. Peters
Keyword(s):  
Ovarian Function ◽  
Post Treatment ◽  
Control Group ◽  
Corpora Lutea ◽  
Gnrh Analogue ◽  
Plasma Progesterone ◽  
Group 4 ◽  
Buserelin Treatment ◽  
Group 3 ◽  
Ovarian Structure

AbstractAn investigation was conducted into the effect of buserelin treatment on day 12 post mating on ovarian function and plasma progesterone and oestradiol-17 ji concentration in ewes. Changes in ovarian structures were determined, at laparoscopy or after slaughter, 48 h after treatment in 38 control and 41 ewes given an injection of 4 jig buserelin on day 12 post mating (day 0 = day of oestrus). Ovulation rate was higher in buserelin treated (2·76) than in control (1·87) ewes (P < 0·05). Moreover, 41 of the 113 corpora lutea observed in the buserelin group were the result of ovulations that had occurred within 48 h post treatment, compared with two of 71 in the controls (P < 0·05). Blood samples were collected from 10 ewes in each treatment group for hormone analysis. Mean progesterone concentrations tended to be higher, in samples collected from 2 to 6h post treatment, in the buserelin group (4·31 (s.e. 1·32) p.g/1) compared with the control group (3·71 (s.e. 1·44) fig/l. Furthermore, overall mean oestradiol concentrations were lower, during days 13, 14 and 15 post mating, in buserelin treated (0·72 (s.e. 0·26) ngfl) than in control (0·94 (s.e. 0·50) ng/l) ewes (P < 0·05). The results of this study indicate that buserelin treatment on day 12 post mating changes ovarian function.

Strategy for the treatment of puerperal metritis and improvement of reproductive efficiency in cows with retained placenta

2011 ◽  
Vol 59 (2) ◽  
pp. 247-256 ◽  
Author(s):  
Wen-Bor Liu ◽  
Shih-Te Chuang ◽  
Ching-Lin Shyu ◽  
Chao-Chin Chang ◽  
Amelia Jack ◽  
...  
Keyword(s):  
Ovarian Function ◽  
Reproductive Efficiency ◽  
Control Group ◽  
Retained Placenta ◽  
Treatment Groups ◽  
Early Postpartum ◽  
Healthy Control ◽  
Group A ◽  
Group B ◽  
Uterine Lavage

The objective of this study was to improve the reproductive efficiency of dairy cows with puerperal metritis (PM) subsequent to retained placenta (RP) using a two-step treatment strategy. A total of 188 postpartum cows, aged from 2 to 8 years, were utilised for 2 experiments. In Experiment 1, cows affected with RP/PM were randomly assigned to two treatment groups. Cows in Group A (n = 17) were treated with 600 mg of ceftiofur intramuscularly for 3 days followed by intrauterine lavage with 0.1% chlorhexidine and infusion with 0.5% povidoneiodine, while cows in Group B (n = 16) received two intrauterine infusions, first with 5 g of oxytetracycline and then with 0.5% povidone-iodine. Cows with normal postpartum findings were regarded as the healthy control group (n = 26). Ultrasonographic examination revealed that the ovarian activities including the appearance of a dominant follicle and days to first ovulation of the cows in Group A during the early postpartum period differed from those of Group B (P < 0.05), which coincided with the results of uterine swabbing for bacteriology. In Experiment 2, cows with normal postpartum findings were allocated to Group D (n = 78), which received an ovulation protocol (GnRH - 7 d PGF2α - 48 h hCG - 24 h AI) on day 50 ± 2 postpartum. Cows affected with PM were randomly divided into two groups, Group E (n = 25) combined the treatments applied in Groups A and D, while Group F (n = 26) repeated the treatment administered in Group E except for uterine lavage. The results indicated that the pregnancy rate within 150 days postpartum and the mean days open in Group E (76.0% and 106.3 ± 4.6 days, respectively) were significantly different from those in Group F (38.5% and 137.9 ± 10.9 days, respectively) (P < 0.05). This study suggests that reproductive efficiency could be improved by using the two-step treatment to regulate uterine involution and an early resumption of ovarian function in cows with RP/PM.

scholarly journals The Effect of 2-Deoxy-N-Glucose on Ovarian Function of Cattle

1978 ◽  
Vol 31 (2) ◽  
pp. 183 ◽  
Author(s):  
TJ McClure ◽  
CD Nancarrow ◽  
HM Radford
Keyword(s):  
Corpus Luteum ◽  
Ovarian Function ◽  
Biochemical Change ◽  
Metabolic Inhibitor ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Energy Deficiency ◽  
Inhibition Of Glycolysis

The administration of the metabolic inhibitor, 2-deoxY-D-glucose (2DG), to four well fed heifers just before and during the time of expected oestrus, and to another heifer following the removal of the corpus luteum, prevented both the occurrence of oestrus and the formation of corpora lutea in all animals. Plasma progesterone concentrations remained low for at least 10--21 days after the last dose of 2DG. The results suggest that the inhibition of glycolysis is associated with the failure of both oestrus and formation of functional corpora lutea, and� they support the hypothesis that hypoglycaemia is the primary biochemical change responsible for infertility induced by acute energy deficiency in lactating cattle.

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