Ovarian follicular development following administration of progesterone or aspiration of ovarian follicles in holstein cows (original) (raw)
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Influence of different doses of progesterone treatments on ovarian follicle status in beef cows
Animal Reproduction Science, 2006
To determine a dose of progesterone (P4) that allow ovarian follicular wave control, Aberdeen Angus cows were randomly assigned into four groups: T600 (n = 5), 600 mg of P4/day; T400 (n = 5), 400 mg of P4/day; T200 (n = 4), 200 mg of P4/day and Control (n = 4) (excipient only). Progesterone was injected from day 3 to 9 of estrous cycle. Ultrasonographies and blood sample collections were performed daily from day 2 to 10 and on day 15 of the estrous cycle. Additionally, an ultrasonographic study was conducted on day 13. Progesterone concentrations were different among all groups (P < 0.01). The diameter of the dominant follicle was greater for control than for T200, T400 and T600 groups (P < 0.01); there was no difference between T200 and T400 (P > 0.05), but they had a greater diameter follicle than the T600 group (P < 0.01). The growth rate of the dominant follicle between day 3 and 7 of estrous cycle was greater for control group (1.63 ± 0.3 mm day −1) than for T200 (0.56 ± 0.19 mm day −1 , P < 0.05), T400 (0.6 ± 0.23 mm day −1 , P < 0.05) and T600 (0.11 ± 0.13 mm day −1 , P < 0.01) groups. The mean number of class I follicles (3-4 mm) per day for the entire experimental period was less for the control group than for T200 (P < 0.05), T400 and T600 (P < 0.01) groups (3.7 ± 1.3; 5.3 ± 1.3; 6.6 ± 1.8 and 8.1 ± 1.9, respectively). The mean number for the T200 group was less than for T600 (P < 0.05) and similar for T400 and T600 groups (P > 0.05).
Two studies were conducted to evaluate the effects of the follicular wave on ovarian function and fertility in dairy heifers and lactating cows. In study 1, the estrous cycle of the selected Holstein heifers was initially synchronized using two intra-muscular prostaglandin F 2α (PGF 2α) administrations 11 days apart. Heifers in group FFW (n = 14) received an intra-muscular 500 μg PGF 2α administration on day 7 after detecting standing estrus, while Heifers in group SFW (n = 14) were administered PGF 2α 13 days after detecting standing estrus. The pregnancy rates of FFW (n = 98) and SFW (n = 100) heifers were also determined 35-37 days after artificial insemination (AI). In Study 2, healthy Holstein lactating cows (n = 28) were randomly assigned to either the FFW (n = 14) or SFW (n = 14) groups. The estrous cycles of the cows were presynchronized using two intra-muscular administrations of PGF 2α given 14 days apart. Then, the emergences of the follicular waves were induced using an Ovsynch protocol. The pregnancy rate of FFW (n = 99) versus SFW (n = 98) cows was also determined 35-37 days after AI. The ovulatory follicle and corpus luteum (CL) resulting from the ovulatory follicle of FFW were larger than those of the dominant follicle and the CL of SFW in dairy heifers and lactating cows. However, the pregnancy rate did not differ between the FFW and SFW groups in heifers and lactating cows 35-37 days after AI. In conclusion, although the characteristics of the ovulatory follicles in FFW versus SFW animals differed, the follicular wave in dairy heifers or lactating cows did not affect fertility.
Animal Reproduction, 2021
We aimed to compare the effect of three estradiol benzoate (EB) doses on follicular wave emergence (FWE) and dominant follicle growth of suckled Nelore cows submitted to TAI (D0). On a random day of estrous cycle (D−10), multiparous (MULT; n=36) and primiparous (PRIM; n=20) suckled Nelore cows received an intravaginal progesterone (P4) device and were assigned in three groups. Cows in the EB-1 (n=20), EB-1.5 (n=15) or EB-2 (n=21) groups received, respectively, an im treatment with 1, 1.5 or 2 mg EB. A subgroup (n=10-13 cows/group) were subject to daily ovarian evaluations from D−10 to D0. On D−2, P4 devices were removed, and all cows received the same treatment: 1 mg estradiol cypionate, 0.53 mg sodium cloprostenol, and 300 IU eCG. Statistical analyses were performed considering only the main effects of treatment group and parity order. The proportion of cows with a synchronized FWE and the moment of the FWE did not differ (p>0.05) among the treatment groups (overall: 80% [28/35] and 4.1 ± 0.4 days); however, the FWE occurred earlier (p=0.007) in MULT (3.8 ± 0.2 days) than PRIM (5.1 ± 0.4) cows. The proportion of animals detected in estrus was greater (86% [31/36] vs. 70% [14/20]; p=0.02) and the dominant follicle was larger on D−2 (9.7 ± 0.3 mm vs. 7.8 ± 0.7 mm; p=0.006) and D0 (11.9 ± 0.4 mm vs. 10 ± 0.5 mm; p=0.008) in MULT than PRIM cows. In conclusion, the three EB doses presented similar efficiency to synchronize the FWE in suckled Nelore cows. Moreover, a delayed FWE and smaller dominant follicle is observed in PRIM cows, contributing to the reduced reproductive performance in this parity category when using similar TAI protocols of MULT cows.
Endocrine and ovarian responses associated with the first-wave dominant follicle in cattle
Biology of Reproduction, 1992
To examine endocrine and biochemical differences between dominant and subordinate follicles and how the dominant follicle affects the hypothalamic-pituitary-ovarian axis in Holstein cows, the ovary bearing the dominant follicle was unilaterally removed on Day 5 (n = 8), 8 (n = 8), or 12 (n = 8) of synchronized estrous cycles. Follicular development was followed daily by ultrasonography from the day of detected estrus (Day 0) until 5 days after ovariectomy. Aromatase activity and steroid concentrations in first-wave dominant and subordinate follicles were measured. Intact dominant and subordinate follicles were cultured in 4 ml Minimum Essential Medium supplemented with 100 aCi 5H-leucine to evaluate de novo protein synthesis. Five days after unilateral ovariectomy, cows were resynchronized and the experiment was repeated. Follicular growth was characterized by the development of single large dominant follicles, which was associated with suppression of other follicles. Concentrations of estradiol-17 (E,) in follicular fluid and aromatase activity of follicular walls were higher in dominant follicles (438.9 ± 45.5 ng/ ml; 875.4 ± 68.2 pg E2/follicle) compared to subordinate follicles (40.6 ± 69.4 ng/ml; 99.4 ± 104.2 pg E2/follicle). Aromatase activity in first-wave dominant follicles was higher at Days 5 (1147.1 ± 118.1 pg E2/follicle) and 8 (1028.2 ± 118.1 pg E2/ follicle) compared to Day 12 (450.7 ± 118.1 pg E2/follicle). Concentrations of E, and androstenedione in first-wave dominant follicles were higher at Day 5 (983.2 ± 78.2 and 89.5 ± 15.7 ng/ml) compared to Days 8 (225.1 ± 78.6 and 5.9 ± 14.8 ng/ ml) and 12 (108.5 ± 78.6 and 13.0 ± 14.8 ng/ml). Concentrations of progesterone in subordinate follicles increased linearly between Days 5 and 12 of the estrous cycle. Plasma concentrations of FSH increased from 17.9 ± 1.4 to 32.5 ± 1.4 ng/ml between 0 and 32 h following unilateral removal of the ovary with the first-wave dominant follicle. Increases in plasma FSH were associated with increased numbers of class 1 (3-4 mm) follicles in cows that were ovariectomized at Day 5 or 8 of the cycle. Unilateral ovariectomy had no effects on plasma concentrations of UI when a CL was present on the remaining ovary. First-wave dominant follicles incorporated more 'H-leucine into macromolecules and secreted high (90000-120000) and low (20 000-23000) molecular weight proteins that were not as evident for subordinate follicles at Days 8 and 12. Results indicate that evolution of the first-wave dominant follicle and the CL have important effects on plasma FSH and LH which regulate ovarian folliculogenesis and steroidogenesis.
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, 1993
Three experiments evaluated the effects of estradiol valerate (EV) on ovarian follicular and CL dynamics, intervals to estrus and ovulation, and superovulatory response in cattle. Experiment 1 compared the efficacy of two norgestomet ear implants (Crestar and Syncro-Mate B; SMB) for 9 d (with PGF at implant removal), combined with either 5 mg estradiol-17b and 100 mg progesterone (EP) or 5 mg EV and 3 mg norgestomet (EN) im at the time of implant insertion on CL diameter and follicular wave dynamics. Ovaries were monitored by ultrasonography. There was no effect of norgestomet implant. Diameter of the CL decreased following EN treatment (P < 0.01). Mean (AE S.D.) day of follicular wave emergence (FWE) was earlier (P < 0.0001) and less variable (P < 0.0001) in EP-(3.6 AE 0.5 d) than in EN-(5.7 AE 1.5 d) treated heifers. Intervals from implant removal to estrus (P < 0.001) and ovulation (P < 0.01) were shorter in EN-(45.7 AE 11.7 and 74.3 AE 12.6 h, respectively) than in EP-(56.4 AE 14.1 and 83.3 AE 17.0 h, respectively) treated heifers. Experiment 2 compared the efficacy of EP versus EN in synchronizing FWE for superovulation in SMB-implanted cows. At random stages of the estrous cycle, Holstein cows (n = 78) received two SMB implants (Day 0) and were randomly assigned to receive EN on Day 0 or EP on Day 1. Folltropin-V treatments were initiated on the evening of Day 5, with PGF in the morning and evening of Day 8, when SMB were removed. Cows were inseminated after the onset of estrus and embryos were recovered 7 d later. Nonlactating cows had more CL (16.7 AE 11.3 versus 8.3 AE 4.9) and total ova/embryos (14.7 AE 9.5 versus 7.9 AE 4.6) than lactating cows (P < 0.05). EP-treated cows tended (P = 0.09) to yield more transferable embryos (5.6 AE 5.2) than EN-treated cows (4.0 AE 3.7). Experiment 3 compared the effect of dose of EVon ovarian follicle and CL growth profiles and synchrony of estrus and ovulation in CIDR-treated beef cows (n = 43). At random stages of the estrous cycle (Day 0), cows received a CIDR and no further treatment (Control), or an injection of 1, 2, or 5 mg im of EV. On Day 7, CIDR were removed and cows received PGF. Follicular wave emergence occurred within 7 d in 7/10 Control cows and 31/32 EV-treated cows (P < 0.05). In responding cows, interval from treatment to FWE was longer (P < 0.05) in those treated with 5 mg EV (4.8 AE 1.2 d) than in those treated with 1 mg (3.2 AE 0.9 d) or 2 mg (3.4 AE 0.8 d) EV, while Control cows were intermediate (3.8 AE 2.0 d). Diameter of the dominant follicle was smaller (P < 0.05) at CIDR removal and tended (P = 0.08) to be smaller just prior to ovulation in the 5 mg EV group (8.5 AE 2.2 and 13.2 AE 0.6 mm, respectively) than in the Control (11.8 AE 4.6 and 15.5 AE 2.9 mm, respectively) or 1 mg EV (11.7 AE 2.5 and 15.1 AE 2.2 mm, respectively) groups, with the 2 mg EV group (10.7 AE 1.5 and 14.3 AE 1.7 mm, respectively) intermediate. Diameter of the dominant follicle at CIDR removal was less variable (P < 0.01) in the 2 and 5 mg EV groups than in the Control group, and intermediate in the 1 mg EV group. In summary, treatment with 5 mg EV resulted in a longer and more variable interval to follicular wave emergence than treatment with 5 mg estradiol-17b, which affected preovulatory dominant follicle size following progestin removal, and may have also affected superstimulatory response in Holstein cows. Additionally, 5 mg EV appeared to induce luteolysis in heifers, reducing the interval to ovulation following norgestomet removal. Conversely, intervals to, and synchrony of, follicular wave emergence, estrus and ovulation following treatment with 1 or 2 mg EV suggested that reduced doses of EV may be more useful for the synchronization of follicular wave emergence in progestogen-treated cattle.
Plasma estradiol, FSH and LH concentration after dominant follicle aspiration in the cow
1999
This work investigates the estrogenic role of the dominant follicle with regard to regulation of plasma FSH and LH concentration. Eight Holstein-Friesian cows were used for aspiration of the dominant follicle using ultrasound guidance during the early, mid and late stages of the luteal phase. Blood samples were collected at 15min intervals from 4 h before until 7 h after aspiration. Plasma progesterone concentration increased from 0.7 to 7.2 ng mL-' from early to mid luteal phase and then fell slightly to 5.9 ng mL-' in the late luteal phase, but remained unaffected by follicle puncture. The follicular aspirate contained a thousandfold higher estradiol, than plasma concentration but its estradiol : progesterone ratio remained at around 2 at each stage of the luteal phase. Aspiration caused plasma estradiol concentration to fall from 1.4 to 0.7, 1.8 to 1.0 and 1.7 to 0.8 pg mL-' in the early, mid and late stages of the luteal phase, respectively (PC 0.05). At the same time, mean plasma FSH concentration was increased from 1.1 to 1.8,1.7 to 2.9 and 0.8 to 1.9 ng mL" (PcO.OS), respectively. The results suggest that estradiol secreted from dominant follicles selectively regulates gonadotropin secretion, since aspiration of the dominant follicle at any stage of the cycle affected circulating FSH but did not appear to influence the mean LH concentration. o 19% by ~isevier science IIIC.
Exogenous hormonal manipulation of ovarian activity in cattle
Domestic Animal Endocrinology, 2002
To achieve precise control of the oestrous cycle in cattle it is necessary to control both the life span of the corpus luteum and the follicle wave status at the end of the treatment. Antral follicle growth in cattle occurs in distinct wavelike patterns during the ovarian cycle and the postpartum anoestrous period. The emergence of each new wave is stimulated by a transient increase in FSH. Each follicle wave has an inherent life span of 7-10 days as it progresses through the different stages of development, viz., emergence, selection, dominance and atresia or ovulation. The dominant follicle (DF) is distinguishable from other subordinate follicles by its enhanced capacity to produce oestradiol, maintenance of low intrafollicular concentrations of insulin-like growth factor binding proteins-2,-4 and-5 and follistatin and an increase in free intrafollicular concentrations of IGF-I as well as an increase in size. Three approaches can be taken to control ovarian activity and regulate the oestrous cycle in cattle: (i) use of the luteolytic agent prostaglandin F2␣ (PGF2␣) alone or one of its potent analogues, (ii) administration of exogenous progesterone-progestagen treatments combined with the use of exogenous oestradiol or gonadotrophin releasing hormone (GnRH) to control new follicle wave emergence and shorten the life span of the corpus luteum, and (iii) prior follicle wave synchrony followed by induced luteolysis. A number of different oestrous synchronisation regimens, viz., PGF2␣-based only, short-term progesterone with prior follicle wave synchrony using oestradiol or GnRH have been developed but the problem of obtaining good follicle wave synchrony and CL regression limit their widespread application. GnRH-prostaglandin-GnRH regimens have recently been developed for beef and dairy cows. However, their success is variable. A better understanding of the hormonal control of follicle growth is a prerequisite in order to obtain more precise control the oestrous cycle allowing one AI at a predetermined time giving high pregnancy rates without recourse to detection of oestrus.