Influence of different doses of progesterone treatments on ovarian follicle status in beef cows (original) (raw)
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Theriogenology, 2001
The objective of this study was to compare the effects of administration of a single injection of progesterone (P4) and follicle aspiration on Day 7 of the estrous cycle on the timing and synchrony of follicular wave emergence, time of ovulation, and concentrations of P4, estradiol and FSH in Holstein cows. Twenty cows were assigned to 4 groups (n=5 cows per group) in a 2 by 2 factorial arrangement. Cows were treated on Day 7 (Day 0 = estrus) of the estrous cycle with either sham follicular aspiration and an oil vehicle administered intramuscularly (control), aspiration of ovarian follicles (aspiration), 200 mg ofP 4 im, or aspiration and 200 mg ofP 4 im (aspiration + P4)-On Day 11, PGF2a (25mg) was administered to all groups. Synchrony of ovulation was less variable in each of the treatment groups compared with the control group (P<0.05), whereas ovulation was delayed in cows in the P4 group (P<0.05). Day of follicular wave emergence was delayed in the cows of the P4 group compared with cows in the aspiration and aspiration + P4 groups (P<0.01), whereas variability in wave emergence was less among both groups of aspirated cows compared with the cows in the control group (P<0.01). More follicles 4 to 7 mm in diameter were detected in the 2 aspiration groups compared with the cows in the control and P4 group (P<0.05). No difference was detected among groups in the maximum concentration of FSH associated with follicular wave emergence. We conclude that both the administration of P4 and the aspiration of follicles on Day 7 of the estrous cycle improves the synchrony of ovulation when luteolysis is induced on Day 11 and results in similar concentrations of FSH at the time of follicular wave emergence, but the timing of wave emergence and the number of follicles post-emergence differ.
Reproduction, Fertility and Development, 2004
The objective was to characterize ovarian follicular dynamics in beef cows treated with a CIDR (Bioniche Animal Health; Belleville, Ontario, Canada) and an injection of estradiol-17β (E2), with or without progesterone (P4), late in the estrous cycle. Previously synchronized, non-lactating, crossbred beef cows (n=36) received a CIDR (Day 0) 16 to 18 days after ovulation and were randomly allocated to one of three treatment groups: no further treatment (Control, n=12), an injection of 5mg E2 (E2, n=12), or 5mg E2 plus 100mg P4 (E2P4, n=12; both from Sigma Chemical Co., St.Louis, MO, USA) i.m. in 2mL canola oil. On Day 7, CIDR were removed and cows received 500μg i.m. of cloprostenol (Estrumate, Schering Plough Animal Health, Pointe-Claire, Quebec, Canada). Ovaries were examined once daily by transrectal ultrasonography to detect ovarian follicle growth profiles, and determine the time of ovulation. Blood samples were taken daily for progesterone determination. Data were analyzed by AN...
science-line, 2024
The manipulation of follicular waves through hormonal treatments, such as estrogen administration, plays a crucial role in optimizing in-vivo oocyte collection for assisted reproductive technologies. The present study aimed to evaluate the effect of two specific types of estrogen on follicular wave dynamics and their impact on in-vivo oocyte collection in Brown Swiss cows. Fourteen cows, in their first lactation, weighing approximately 340 kg were randomly assigned to one of two treatments including T1 (estradiol cypionate) and T2 (estradiol benzoate). Both treatments were administered at 1.2 mg of estrogen, at day 0 of the experiment. All Brown Swiss cows were provided with a diet entirely consisting of alfalfa grazing. On day 7, follicular wave dynamics were assessed using a DP-50 vet ultrasound device equipped with a 7.5 MHz transducer for transvaginal follicular aspiration guidance. Follicle counts were categorized into three size ranges including 2-4 mm (small), 4-8 mm (medium), and greater than 8 mm (large). Additionally, the quantity and quality (viable oocytes) of the collected oocytes were evaluated by the Ovum Pick Up (OPU) team for oocyte viability on day 7. The study assessed the follicular dynamics (number of follicles) and efficiency of oocyte collection (viable oocytes) in cows treated with Estradiol Cypionate (T1) and Estradiol Benzoate (T2). The average number of small, medium-sized, and large follicles size were 6.048 ± 6.037, 3.16 ± 2.01, and 0.53 ± 0.67 respectively. The total number of follicles was 9.59 ± 3.56. The mean number of viable oocytes recovered was 3.024 ± 1.66, while the mean number of non-viable oocytes was 1.47 ± 1.01. The results indicated no significant differences between treatments in the size of small, medium, and large follicles, nor in the total number of follicles and viable oocytes recovered. However, a significant difference was observed in the number of non-viable oocytes recovered, with a higher mean in T2 (1.86) compared to T1 (1.09). The results indicated an adequate follicular response and viable oocyte recovery in both treatment groups (estradiol cypionate and estradiol benzoate). However, variations in oocyte viability were observed, with estradiol cypionate showing a slight advantage.
Theriogenology, 2002
We studied the relationship between progesterone (P 4 ) concentrations early in the estrus cycle and follicular dynamics in dairy goats. We used seven untreated goats (control group) and six progesterone treated goats (P group) with a controlled internal drug release device from Days 0 to 5 (Day 0: day of ovulation). We performed daily ultrasonograph during the interovulatory interval to determine ovarian change and took daily blood samples to determine serum estradiol 17b (E 2 ) and P 4 concentrations by RIA. We divided the control goats into 3-(n 4) and 4-wave goats (n 3), according to the number of follicular waves recorded during the ovulatory cycle. Mean progesterone concentrations between Days 1 and 5 were higher and mean estradiol concentrations between Days 3 and 5 were lower in 4-wave goats (P 4 : 3:8 AE 0:2 ng/ml; E 2 : 1:6 AE 0:2 pg/ml) than in 3-wave goats (P 4 : 2:0 AE 0:5 ng/ml, P 0:05; E 2 : 4:4 AE 0:9 pg/ml, P 0:05). Wave 2 emerged earlier in 4-wave (Day 4:2 AE 0:3) than in 3-wave goats (Day 7:3 AE 0:3, P 0:05). Three out of six of the progesteronetreated goats had short cycles (mean 8:0 AE 0:0 days) and ovulated from Wave 1. The other three goats had shorter cycles (mean 18:3 AE 0:3 days) than the control group (20:0 AE 0:2 days; P 0:05), although they were within the normal range of control cycles (shortened cycles). In the three treated goats with shortened cycles (two with four waves, one with three waves), mean progesterone concentrations between Days 1 and 5 were higher (4:7 AE 0:6 ng/ml) than in the 3-wave control goats. In these goats, Wave 2 emerged at Day 4:3 AE 0:3, similar to the time observed in 4-wave goats but earlier (P 0:05) than in 3-wave control goats. Overall results con®rm a relationship between the progesterone levels and the follicular wave turnover during the early luteal phase in the goat. Higher progesterone concentrations may accelerate follicular turnover probably by an early decline of the negative feedback action of the largest follicle of Wave 1. This is followed by an early emergence of Wave 2. #
Cerri, 2011- progesterone;development of the ovulatory follicle
Two experiments evaluated the influence of altering the concentrations of progesterone during the development of the ovulatory follicle on the composition of the follicular fluid, circulating LH and PGF 2α metabolite (PGFM), and expression of endometrial progesterone receptor and estrogen receptor-α. In both experiments, the estrous cycles were presynchronized (GnRH and progesterone insert followed by insert removal and PGF 2α 7 d later, and GnRH after 48 h) and cows were then enrolled in 1 of 2 treatments 7 d later (study d −16): high progesterone (HP) or low progesterone (LP). In experiment 1 (n = 19), cows had their estrous cycle synchronized starting on study d −9 (GnRH and progesterone insert on d −9, and insert removal and PGF 2α on d −2). In experiment 2 (n = 25), cows were submitted to the same synchronization protocol as in experiment 1, but had ovulation induced with GnRH on study d 0. In experiment 1, plasma was sampled on d −4 and analyzed for concentrations of LH; the dominant follicle was aspirated on d 0 and the fluid analyzed for concentrations of progesterone, estradiol, and free and total IGF-1. In experiment 2, follicular development and concentrations of progesterone and estradiol in plasma were evaluated until study d 16. Uterine biopsies were collected on d 12 and 16 for progesterone receptor and estrogen receptor-α protein abundance. An estradiol/oxytocin challenge for PGFM measurements in plasma was performed on d 16. In experiments 1 and 2, LP cows had lower plasma concentrations of progesterone and greater concentrations of estradiol, and had larger ovulatory follicle diameter (20.4 vs. 17.2 mm) at the end of the synchronization protocol than HP cows. Concentration of LH tended to be greater for LP than HP cows (0.98 vs. 0.84 ng/ mL). The dominant follicle of LP cows had greater concentration of estradiol (387.5 vs. 330.9 ng/mL) and a lower concentration of total IGF-1 (40.9 vs. 51.7 ng/ mL) than that of HP cows. In experiment 2, estradiol and progesterone concentrations did not differ between treatments from d 0 to 16; however, the proportion of cows with a short luteal phase tended to increase in LP than HP (25 vs. 0%). Concentrations of PGFM were greater for LP than HP. Uterine biopsies had a greater abundance of progesterone receptor, and tended to have less estrogen receptor-α abundance on d 12 compared with d 16. An interaction between treatment and day of collection was detected for estrogen receptor-α because of an earlier increase in protein abundance on d 12. Reduced concentrations of progesterone during the development of the ovulatory follicle altered follicular dynamics and follicular fluid composition, increased basal LH concentrations, and prematurely increased estrogen receptor-α abundance and exacerbated PGF 2α release in the subsequent estrous cycle.
Tropical Animal Health and Production, 2014
In beef and dairy cattle, the number of follicular waves affects endocrine, ovarian, and behavioral events during a normal estrous cycle. However, in Mexican-native Criollo cattle, a shortly and recently domesticated breed, the association between wave patterns and follicular development has not been studied. The objective of this study was to evaluate the effect of number of follicular waves in an estrous cycle on development of anovulatory and ovulatory follicles, corpus luteum (CL) development and functionality, as well as estrual behavior in Criollo cows. Ovarian follicular activities of 22 cycling multiparous Criollo cows were recorded daily by transrectal ultrasound examinations during a complete estrous cycle. Additionally, blood samples were collected daily to determine serum progesterone concentrations. Only two-(n=17, 77.3 %) and three-wave follicular (n=5, 22.7 %) patterns were observed. Duration of estrus, length of estrous cycle, and length of follicular and luteal phases were similar (P>0.05) between cycles of two and three waves. Two-wave cows ovulated earlier (P<0.05) after detection of estrus than three-wave cows. Detected day and maximum diameter of first anovulatory follicle were not affected (P>0.05) by number of waves. Growth rate of first dominant follicle was higher (P<0.05) in three-wave cycles. Onset of regression of the first dominant follicle was earlier (P<0.01) in cycles with three waves than in those with two waves. In two-wave cycles, ovulatory follicles were detected earlier (P<0.01) and had lower (P < 0.01) growth rate than in three-wave cycles. Development (i.e., maximum diameter and volume) and functionality (minimum and maximum progesterone concentration) of CL were similar (P>0.05) between two-and threewave patterns. In conclusion, Criollo cows have two or three follicular waves per estrous cycle, which alters partially ovulatory follicle development and ovulation time after detection of estrus. Length of estrous cycle, as well as CL development and functionality, was not affected by number of follicular waves.
J Reprod Fertil
This study, compared the endocrine function of dominant follicles of the first and second follicular waves (DF1 and DF2, respectively) and the corpora lutea that were subsequently formed. In the experiments conducted in vitro, ovaries were collected from dairy cows on day 6.1 \m=+-\0.2 or day 14.8 \m=+-\0.2of the oestrous cycle to obtain steroidogenically active DF1 (n = 8) and DF2 (n = 7). Granulosa and thecal cells were isolated, dispersed and incubated for 16 h with testosterone (granulosa cells) or forskolin or bLH (thecal cells). Both types of cell were subsequently cultured for 9 days with forskolin and insulin. The viability of the granulosa cells was similar in DF1 and DF2, but the concentration of oestradiol in the follicular fluid was higher in DF1 than in DF2. Production of oestradiol and progesterone by granulosa cells was similar in DF1 and DF2, but androstenedione and progesterone production by thecal cells were 3.5-6.5-fold higher in DF1 than in DF2. During the 9 days of luteinization, progesterone production was similar in DF1-and DF2-derived granulosa cells, but was two-to three\x=req-\ fold higher in DF1-than in DF2-derived thecal cells. Experiments were also conducted in vivo. In Expt 1 in vivo, lactating cows that were assigned to ovulate DF1 or DF2 (n = 9 and 13 in replicate 1 and 2, respectively) were injected with PGF2\g=a\ on days 6 and 7 or on days 14 and 15 of the oestrous cycle, respectively. A wave by replicate interaction was detected for plasma progesterone concentration in the subsequent cycle: in the first replicate, progesterone production was approximately 40% higher in cows that ovulated DF1; in the second replicate, progesterone production was similar in cows that ovulated DF1 or DF2. In Expt 2, pooled plasma progesterone in the mid-luteal phase (days 12-15) after insemination of pregnant and non-pregnant cows was approximately 30% higher in cows that had ovulated DF1 (n = 32) than in cows that had ovulated DF2 (n = 22). This study showed DF1 had a higher steroidogenic capacity compared with DF2, which may be related to the hormonal environment in which the follicles developed.
Effect of Induced Suprabasal Progesterone Concentrations on Follicular Dynamics in Heifers
Reproduction in Domestic Animals, 1994
To investigate the influence of induced suprabasal plasma concentrations of progesterone after luteolysis on follicular dynamics, heifers were allocated to receive subcutaneous silicone implants containing 2.5 (n = 4), 5 (n = 4), 6 (n = 3), 7.5 (n = 3) or 10 g (n = 4) of progesterone, or a blank implant (controls, n = 5 ) . The implants were intended to produce plasma progesterone concentrations under 3 nmol/L. They were inserted on day 8 of the cycle (day 0 = ovulation) and left in place for 17 days. Ovaries were ultrasonically scanned daily until day 14, at 12-h intervals from day 15 to 26, and daily again until day 30. The growth pattern of the dominant follicle of the first follicular wave was not different between control and treated heifers. The ovulatory follicle emerged on days 11-15, and in control heifers and heifers treated with 2.5 and 5 g of progesterone, it reached its largest diameter on days 19-22, just before ovulation. In heifers treated with 6, 7.5 and l o g , the ovulatory follicle prolonged its growth for a longer period ( P < 0.05) and to a larger diameter ( P < 0.05), after which it reached a static phase before ovulation. The interovulatory interval was consequently prolonged ( P < 0.05) as compared to controls. During the extended dominance of the ovulatory follicle there was a total absence of follicular recruitment, and a new follicular wave emerged shortly after ovulation. In heifers treated with 10 g, emergence of the postovulatory wave was delayed ( P < 0.05).
Animal Reproduction Science, 1994
The aim of this study was to characterise the luteal and follicular response to artificially elevated concentrations of progesterone during the metoestrous phase of the oestrous cycle of heifers. An intravaginal controlled internal drug releasing (CIDR) device containing 1.9 g progesterone was inserted at either Day 1 of the cycle (oestrus designated Day 0) for 4 days (T 1; n = 12), or on Day 4 for 5 days (T4; n= 11). A third group of heifers (CTRL; n= 13) remained untreated. The diameters of the corpus luteum (CL) and all follicles of at least 5 mm were recorded daily in ovaries of eight heifers from each group by transrectal ultrasonography throughout the cycle. A blood sample was collected daily from every heifer to determine the concentrations of progesterone and iuteinising hormone (LH) in sera. Two of the heifers with elevated progesterone levels from Day l had 'short' cycles which were characterised by ovulation of the first dominant follicle following the premature demise of the CL. These data are considered separately from the general analysis. Progesterone concentrations of heifers in both treatment groups were elevated (P< 0.05) during the period of CIDR insertion, but were not different at the mid-cycle phase compared with untreated contemporaries. A sustained decline to basal concentrations of progesterone occurred earlier (P< 0.05) in heifers treated from Day 1. Elevated progesterone concentrations were associated with decreased (P< 0.05) mean concentrations of LH on Days 4 and 5 in heifers of the Tl group, but only on Day 5 in the T4 group. The average diameter of the corpus luteum (CL) of treated heifers from Days 8 to 18 was less than in untreated heifers (Days 11-13 and 16-18, P<0.05). Heifers in the T1 group had either one or two waves of follicle turnover, with a mean inter-oestrus interval of 8 days and 18 days, respectively. In contrast, heifers in other groups had some two-wave but mostly three-wave cycles and mean inter-oestrus intervals of about 21 days. Premature elevation of progesterone reduced (P < 0.05) the size of the first dominant follicle in both treated groups of heifers. Administration of progesterone during the early and late metoestrous phase of the oestrous cycle in heifers reduced the diameters of the CL and the first dominant follicle. Elevation of progesterone from Days 1 to 5, hut not from Days 4 to 9, reduced the lifespan of the CL to produce 'short' and 'shortened' cycles, with either one or two follicle waves, respectively.