This study evaluated the efficiency of two d-cloprostenol injections at different intervals on the reproductive parameters of dairy goats. Trial 1 comprised 54 goats allocated to receive two 37.5μg d-cloprostenol doses at intervals of seven (T7, n=19), 10 (T10, n=18), and 11.5 (T11.5, n=17) days. Trial 2 comprised 62 goats allocated to receive injections at T7 (n=30) and T11.5 (n=32). Ultrasonography was done and blood was collected just before d-cloprostenol injections. After the second dose, goats were artificially inseminated (AI) with frozen-thawed semen at 18-24h (Trial 1) or at 10-24h (adjusted according to the time of estrus onset in Trial 2) after estrus detection. Estrus response rate did not differ (P>0.05) among groups in Trials 1 (T7=94.7%; T10=88.9%; T11.5=88.2%) and 2 (T7=90.0%; T11.5=96.9). All females showed progesterone concentrations >1ng/mL before both d-cloprostenol injections. The largest follicle diameter present on ovaries was similar (P>0.05) among treatments at the first and second dose. The second largest follicle diameter was superior (P<0.05) to T7 than to T10 and T11.5 goats at first dose only. This possibly resulted in lower interval to estrus (P<0.05) in T7-treated goats than other treated goats in both trials. The conception rate was similar among treatment groups in Trials 1 (T7=55.6%; T10=18.8%; T11.5=26.7%) and 2 (T7=85.2%; T11.5=93.6%). The three treatments efficiently synchronized estrus. T7 and T11.5 protocols resulted in high estrus synchrony and conception rates when adjusting the AI time according to interval of estrus.

This study monitored the long-term follicular dynamics and changes in ovarian steroid hormones associated with an experimental model of cystic ovarian degeneration (COD) in the heifer. In the treated group (n = 7), Holstein heifers received a single injection of 500 microg of cloprostenol (prostaglandin F2a, PG) and 5 mg of estradiol valerate (EV) on either Day 17, 18 or 19 of the estrous cycle. The control group (n = 7) received only PG. Transrectal ultrasound was performed daily, beginning 8 to 10 d before injection and continuing until a return to normal cyclicity (40 to 74 d). Blood samples were taken twice daily over the same period. The EV disrupted the normal follicular development as well as the plasma progesterone and estradiol profiles of 6/7 heifers in the treated group. Two different types of responses were observed. The Type-I response (n = 2) was characterized by a premature ovulation followed by a corpus luteum (CL) which persisted for over 30 d. The Type-II response (n = 4) was characterized by anovulation followed by the emergence of a large ovarian structure which could further be subtyped. In Type- IIA (n = 2), this follicle ovulated at an exaggerated size of 19 or 24 mm (mean diameter of controls: 13.4 +/- 2.7 mm). The subsequent cavernous CL was very large at 35 and 37 mm (mean diameter of CL in controls: 23.8 +/- 2.0 mm). In Type- IIB (n = 1), the follicle present at the time of injection continued to grow and became a luteinized cyst. In Type-IIC (n = 1), several waves of follicular cysts developed and persisted for 52 d. This study suggests that EV induces a range of ovarian dysfunctions including different forms of COD. The individual differences in the stage of folliculogenesis at the time of injection of EV may be responsible for the different types of responses.

The objectives of this study were to assess the association of a 4-point scale of vaginal discharge score (VDS) with time to pregnancy to define criteria for a practical case of purulent vaginal discharge (PVD) in dairy cows, to test the risk factors for PVD, and, finally, the effect of a dose of PGF2α on cure and reproductive performance. In experiment 1, grazing Holstein cows (n = 2,414) had their vaginal discharge scored at ∼32 d in milk (DIM) on a 4-point scale, the effect of VDS on the hazard of pregnancy by 300 DIM was then assessed to derive a case definition of PVD. Risk factors for PVD and self-cure were also assessed. In experiment 2, grazing Holstein cows (n = 6,326) from 5 herds were checked for PVD at ∼30 DIM. Cows with PVD were assigned to receive one dose of 500 μg of PGF2α analog (Cloprostenol; Ciclase, Syntex SA, Buenos Aires, Argentina) per cow (odd ear tag number) or to remain untreated (even tag number). Cure was declared if cows presented clear normal vaginal discharge (VDS-0) at visit 2 (∼62 DIM). Data were analyzed with Cox's regression and mixed logistic models. In experiment 1, cows with VDS ≥1 had lower hazard of pregnancy and longer calving to pregnancy interval than cows with VDS-0. This finding was not affected by the time at which the diagnosis was performed. Therefore, a cow ≥21 DIM and having VDS ≥1 was used to define a case of PVD. The odds of PVD were greater in primiparous cows compared with multiparous, in cows with abnormal calving compared with those with normal calving, and in those losing BCS peripartum. In experiment 2, PGF2α treatment tended to slightly increase the hazard of pregnancy (adjusted hazard ratio = 1.13). Conversely, PGF2α had no effect on the odds of cure of PVD [adjusted odds ratio (AOR) = 1.19], pregnancy at first service (AOR = 1.03), or pregnancy by 100 DIM (AOR = 0.89) or 200 DIM (AOR = 1.27). In conclusion, cows with VDS ≥1 can be considered to have PVD because of their lower hazard of pregnancy and longer calving to pregnancy interval (up to 48 d). Important risk factors are parity, calving, and body condition score loss peripartum. Optimal time of diagnosis is ≥28 to 35 DIM because cows experience a high self-cure rate. Self-cure is also affected by parity, prepartum BCS, and VDS. Finally, as treatment with one dose of PGF2α had a small effect on the hazard of pregnancy and no effect on clinical cure, its therapeutic use in grazing dairy cows with PVD is not recommended.

A field trial was conducted to elucidate the effect of the time of initiation of a repeated PGF2alpha-application in a 14 day interval for treatment of endometritis in dairy cows. On a commercial dairy farm in Brandenburg, Germany, a total of 494 dairy cows were examined by rectal palpation and adspection for signs of endometritis (vaginal discharge, enlarged uterus) between day 20 to 26 post partum (dpp). We performed two further examinations by rectal palpation and external adspection to monitor the puerperal phase (34.-40. dpp, 55.-61. dpp). All cows with symptoms of an endometritis were treated with PGF2alpha (0.15 mg R-Cloprostenol, Preloban, Intervet Deutschland GmbH Unterschleissheim) twice in a 14-day interval. In the group "Early" (n = 146) the first injection of Cloprostenol was administered at time of the 1st examination. In the group "Late" (n = 129) an identical treatment was administered in cows with endometritis, however it was started 14 days later (34.-40. dpp). The incidence of endometritis was 57.7% in the group "Early" and 53.5% in the group "Late" at the first time of examination. The 1st service conception rates for treated cows were 34% in the group "Early" vs. 37% in the group "Late". In the group "Early" differences were found in days open between treated cows with endometritis and untreated controls without symptoms of endometritis (99.1 d vs. 110.8 d, p>> 0.05). In the group "Late", days open for treated (106.8 d) and untreated cows (108.0 d) were similar. The severity of endometritis influenced the percentage of cows pregnant at 200 dpp. Regarding cows with a severe endometritis (E2 and E3) the percentage of pregnant cows 200 dpp was higher in the group treated early (E2: 78.4%; E3: 80.0%) than in the group with the late initiation of the treatment (E2: 68.6%; E3: 54.5%, p < 0.05). Cows with a moderate endometritis (E1) had a similar percentage of pregnant cows (200 dpp) as the untreated cows without endometritis. It is concluded that application of PGF2alpha in the 4th and 6th week post partum in a 14 day interval in cases of severe endometritis is more effective than the application of the same treatment two weeks later.

This trial evaluated the reproductive performance in an early routine oestrus induction programme using two different PGF2α preparations in dairy cattle. D-cloprostenol sodium (n = 192; Group A) or dinoprost (n = 187; Group B) was administered between days 35 and 42 post partum. Also, a group of non-treated cows (n = 135; Group C) was included as control. Pedometers were used to detect oestrus, and also secondary oestrous signs and vaginal mucus quality were assessed prior to artificial insemination (AI). When oestrus was not detected for 14 days after PGF2α administration, the treatment was repeated, up to a maximum of three times. There were no differences between the study groups in oestrus detection (A = 73.48%, B = 73.01%, C = 79.26%; P = 0.428), good mucus quality (A = 96.45%, B = 91.30%, C = 93.45%; P = 0.203) and the presence of mounting lesions (A = 98.58, B = 94.93%, C = 98.13; P = 0.414). First-service pregnancy rates were 19.78%, 15.64% and 32.03% in Groups A, B and C, respectively (P = 0.003). There were no inter-group differences for the interval from parturition to first AI. However, a significantly shorter interval from parturition to conception (92.17 days, 99.45 days, 118.93 days; P = 0.002) and significantly less services per conception (2.12, 2.18, 2.66; P = 0.003) were observed in Groups A and B in comparison with Group C. The use of PGF2α resulted in better fertility in a repetitive, routine postpartum programme, although no differences between Dcloprostenol and dinoprost were detected.

Treatment with cloprostenol, a prostaglandin synthetic analogue, was evaluated in five queens with open-cervix pyometra. Cloprostenol was administered (5 μg/kg body weight SC) on 3 consecutive days and amoxicillin (20 mg/kg body weight IM) on 7 consecutive days. Transient post-injection reactions caused by cloprostenol administration included diarrhea, vomiting and vocalizations. Reactions began as quickly as 10 mins after cloprostenol administration and lasted as long as 30 mins. All queens improved clinically after cloprostenol treatment and remained healthy until the end of the study, 1 year after treatment. All queens resumed normal estrous cycles without further treatment and two (40%) delivered a normal litter. In conclusion, use of cloprostenol is an acceptable treatment for open-cervix pyometra in queens.

We aimed with the present study to evaluate the effects of FSH treatment (200 mg) split in four or six administrations on ovarian follicle stimulation and in vitro oocyte competence for embryo production in dairy cows with synchronized follicular wave emergence. On random days of the estrous cycle (Day 0), non-lactating Holstein cows received a progesterone (P4)-releasing intravaginal device and 2 mg estradiol benzoate IM. On Day 3, they received 0.530 mg sodium cloprostenol (PGF2α) IM. Control cows (n = 35) received no further treatments, whereas FSH-treated cows received 200 mg FSH split in four (FSH4 group; n = 33) or six (FSH6 group; n = 33) administration regimens. Starting on Day 4, cows in FSH4 group received 200 mg FSH split in four equivalent doses of 50 mg 12 h apart. Cows in FSH6 group received the same total FSH dose split in six equivalent doses of 33.3 mg 12 h apart, but treatments started on Day 3. On Day 7 AM (36 h of "coasting" period for FSH-treated groups), the P4 devices were removed and cows were subjected to ovum pick up (OPU). Viable oocytes were in vitro fertilized using sexed-sorted semen. Although FSH treatment did not (P>> 0.1) increase the total number of follicles (Control, 53.2 ± 4.5 vs. FSH-treated, 51.4 ± 3.1), the two hormonal stimulation regimens, FSH4 and FSH6, increased the number of medium follicles (6-10 mm; 5.2 ± 0.5 vs. 18.1 ± 1.4; P < 0.0001) and reduced the number of small follicles (2-5.9 mm; 46.3 ± 5.1 vs. 31.0 ± 2.4 P < 0.0001). Also, FSH treatment or regimen did not increase (P>> 0.1) the number of viable oocytes (Control, 12.6 ± 1.26 vs. FSH-treated, 12.70 ± 1.03), recovery rate (Control, 36.5% vs. FSH-treated, 36%) and the number of in vitro produced blastocyst (Control, 4.1 ± 0.52 vs. FSH-treated 4.3 ± 0.5). We concluded that FSH stimulation protocol proposed herein is effective to stimulate the growth of small antral follicle population prior to OPU, but it was ineffective to improve in vitro oocyte competence for embryo production in non-lactating Holstein cows with synchronized follicular wave emergence.

The probability of a pregnancy decreases substantially in lactating dairy cows treated with Ovsynch if luteolysis is delayed or incomplete. Two PGF(2α) products are currently approved in the United States for luteolysis in lactating dairy cattle, dinoprost tromethamine and cloprostenol sodium. Cloprostenol has a longer half-life compared with dinoprost, is more resistant to endogenous metabolism, and is maintained in circulation longer. We hypothesized that cloprostenol could reduce the time to complete luteolysis compared with dinoprost because of differences in half-life. Lactating dairy cows received the same presynchronization strategy (G6G; 25mg of PGF(2α) - 2 d - 100 μg of GnRH - 6 d - 100 μg of GnRH - 7 d - final PGF(2α) treatment). At the time of the final PGF(2α), cows (n=35) were randomly assigned to receive either 500μg of cloprostenol or 25mg of dinoprost. Blood samples were collected daily before and serially after PGF(2α) treatment to analyze circulating concentrations of progesterone (P(4)) and estradiol (E(2)). Ultrasound examinations of ovaries were performed to measure sizes of follicles and corpora lutea (CL) and determine time of ovulation. Considering only cows with complete luteolysis, mean circulating P(4) was lower for cows given cloprostenol than for those given dinoprost between 0 and 12h postinjection, but not at 24, 36, or 48 h. A rapid decrease in P(4) was observed 1h after PGF(2α) (6.54 ± 0.27 to 3.77 ± 0.22 ng/mL) followed by a complete rebound 1h later (3.77 ± 0.22 to 5.07 ± 0.31 ng/mL) followed by a steady decline in both treatment groups. Serum concentrations of E(2) were greater at 48 h posttreatment in cloprostenol-treated cows (2.74 ± 0.15 pg/mL) than in dinoprost-treated cows (2.37 ± 0.19 pg/mL). Cows that did not have complete luteolysis did not ovulate (0/7) during the 6-d period following treatment. Time to complete luteolysis and ovulation was 29.1 ± 1.1 versus 29.4 ± 1.7 and 101 versus 103 h posttreatment in cloprostenol compared with dinoprost. A negative relationship was observed between P(4) at 12h posttreatment and concentrations of E(2) 48 h posttreatment (b=-0.6905; R(2)=0.23). In summary, cows treated with cloprostenol had lower concentrations of P(4) for the first 12h following treatment and subsequently greater concentrations of E(2) compared with dinoprost, although no differences were observed in these 2 PGF(2α) analogs for time to complete luteolysis or time to ovulation.

This study aimed to evaluate ovarian follicular dynamics in goats submitted to synchronization of estrus and supplemented with diets that differed in the metabolizable energy source and amount of energy. The experiment was carried out using 42 does allocated into three treatments, fed for 9 days with a ration providing 1.0 times maintenance containing maize (1 MM, n = 14) or without maize (1 M, n = 14) or a ration providing 1.5 times maintenance containing maize (1.5 MM, n = 14). Estrus was synchronized with two injections of cloprostenol given 7 days apart. Does were also treated with intravaginal progesterone inserts and eCG. The number of ovulations and size of the follicles were measured using ultrasonography on Days 10, 11, and 12 after the start of the dietary treatment. The interval to estrus and duration of estrus did not differ between treatments (P = 0.382). Does fed with 1 and 1.5 MM had a similar number of ovulations but a greater number of ovulations than goats fed with 1 M (P = 0.028). The mean number of small, medium, large, and total number of follicles on Days 10 to 12 of ultrasound evaluations did not differ (P = 0.204) between treatments, but mean numbers changed over time (P < 0.001). The mean frequency and amplitude of LH pulses and concentrations of glucose, insulin, leptin, and insulin growth factor-1 in plasma were not significantly affected (P>> 0.258) by any of the treatments. In summary, the inclusion of maize in the ration can stimulate ovulation rate at maintenance level. Similar results between groups fed diets that included maize and provided metabolizable energy at 1.0 and 1.5 maintenance demonstrate that to increase the ovulation rate when synchronizing estrous cycles in does, dietary supplementation with maize can be restricted to provide a maintenance level of metabolizable energy only, which would reduce dietary costs.

This study compared the reproductive effects of different dosages of PG-600 (Intervet/Merck Animal Health, Madison, NJ) during the breeding season of ewes. PG-600 is a single-dose injectable product labeled for estrous induction in swine, containing equine chorionic gonadotropin (80 IU/mL) and human chorionic gonadotropin (40 IU/mL). PG-600 is routinely used off-label for out-of-season estrous induction in sheep. However, at the most common dose administered to ewes (5 mL), PG-600 is likely to overstimulate the ovaries, resulting in reduced pregnancy rates. Following estrous synchronization with intravaginal progesterone and cloprostenol, Polypay ewes were treated with 5 mL PG-600 (T1; n = 8), 1.5 mL PG-600 (T2; n = 8), or 5 mL saline (C; n = 8) and then mated to rams. Jugular vein samples were collected prior to the PG-600 injection (0 hr) and at 2, 4, 8, 12, and 24 hr after injection. Serum estradiol-17β was determined by chemiluminescence and among groups using repeated measures analysis of covariance. Ovulation and pregnancy rates were determined by transrectal ultrasonography and compared by one-way ANOVA and chi-square, respectively. Estradiol-17β concentrations were greater in T1 compared to T2 and C (P < 0.001). Ovulation rate was greater (P < 0.001) but pregnancy rate was lower (P < 0.001) in the T1 compared to C and T2. These data confirm that a 5 mL dose of PG-600 administered to ewes during the breeding season overstimulates the ovaries, which may then reduce fertilization or embryo survival. Future research will focus on the effects of different dosages of PG-600 on pregnancy rate of ewes during the nonbreeding season.

Keywords: corpora lutea; estradiol; estrus induction.

Attempts were made to induce delivery in 79 cows and 20 heifers, using the preparations dexametasone, cloprostenol, and dinolytic. The level of progesterone and estradiol was determined in four cows. A group of 20 heifers were injected with the preparation fortecortin at the rate of 30 mg. Four cows with induced parturition were used to evaluate the changes setting in with the blood level of estradiol 17 beta and progesterone. The following conclusions were made: 1. Best effects with regard to the indices duration of calving parturition and post-partal complications, and independence and service period are produced with the combined application of 50 mg sodium selenite and 680 UI vitamin E with 30 mg dexametasone. 2. The decrease in liveweight of the newborn calves from heifers at an average of 6 kg leads to the prevention of dystocia and the shortening of the post-partal period.

In the current study follicular dynamics, pituitary function, ovulatory response and luteal activity of 30 maiden Barbarine sheep were analyzed according to oestrus occurrence and lambing outcome after oestrus synchronisation with cloprostenol. Animals were retrospectively classified in three groups named as O- (n=7, ewes not displaying oestrus), O+L- (n=7, ewes showing oestrus but failing to lamb) and O+L+ (n=16; ewes showing oestrus and lambing thereafter). All the sheep ovulated and daily transrectal ultrasonographies revealed that preovulatory follicles were present at cloprostenol injection in all the animals. In sheep O+L+ and O+L-, 50% and 57% of the ovulatory follicles were the largest follicles at cloprostenol treatment (mean size of 4.1+/-0.26 mm and 4.3+/-0.74 mm, respectively). In O- ewes, the same percentage was higher (86%, P<0.05 when compared to group O+L+; mean size of 4.0+/-0.46 mm). The number of large follicles and the final diameter of the ovulatory follicles at oestrous tended thereafter to be higher in group O+L+ (1.4+/-0.1 and 6.4+/-0.2) than in groups O+L- (1+/-0.2 and 5.7+/-0.36) and O- (0.9+/-0.2 and 5.9+/-0.5, respectively). Conversely, the number of medium follicles at oestrus detection was higher in the group O+L- (2.1+/-0.3, P<0.05) than in the other two groups (1+/-0.2 and 1+/-0.3 for O+L+ and O- respectively). Timing of preovulatory LH surge was earlier for ewes O- (24.0+/-4.75, P<0.05) than for sheep O+L+ and O+L- (37.9+/-2.45 h and 38.0+/-4.75 h, respectively) and 94% of O+L+ ewes had a LH surge between 16 h and 64 h after cloprostenol injection compared to 57% in O+L- and O- groups (P<0.05). Thus, maiden Barbarine sheep failing to display oestrus or conceive showed alterations in their follicular dynamics and, thereafter, pituitary function and ovulatory response.

The relative merits of three hormone treatments of dairy cows: (1) intravaginally administered progesterone and oestradiol benzoate; (2) intravaginally administered progesterone and injected cloprostenol; and (3) injected cloprostenol; begun 35-75 days after calving and designed to synchronize oestrus and ovulation and allow successful artificial insemination (AI) at fixed times, have been assessed utilizing information from progesterone concentrations in milk. From this it was concluded that 89% of the cows had ovulated one to three times between calving and the beginning of treatment. Treatment (2) was more effective than (1) in synchronizing ovulation. This was due to the fact that when treatments began early in the ovulation cycle, the requirement for a rapidly effective luteolytic agent was provided by cloprostenol but not by oestradiol benzoate. Treatment (2) was also more effective than (3) in synchronizing ovulation. This is interpreted as meaning that progesterone treatment for 12 days had a beneficial effect in restoring normal cyclic ovarian function in the cows after calving. Whilst cloprostenol administered alone did not have this beneficial effect, there is no evidence that it had a detrimental effect. Based on all cows in treatment groups, the proportion that became pregnant to the fixed-time AI was significantly greater after treatment (2) than after (1), but when based on numbers of cows with synchronized ovulation, there were no significant differences among treatments in the proportions becoming pregnant. The progesterone/cloprostenol treatment had a disadvantage in that when begun during the 11-22 day period of the ovulation cycle, so resulting in a long, total period of suppression of ovulation (mean, 32.1 days), fertility to the fixed-time AI was poor despite effective synchronization of ovulation. Ovulation cycles immediately following the failed, fixed-time AI were normal, both in length and in maximum, luteal-phase progesterone concentration and indicated normal corpus luteum function. Thus the infertility could be ascribed neither to poor timing of AI nor to gross degeneration of follicles prior to their synchronized ovulation following the prolonged suppression of ovulation. The 12-day progesterone treatments when given to anovulatory cows gave, within 5.5 h of their beginning, a concentration of progesterone in milk that was not significantly different from the maximum reached. This concentration declined during the 12 days of the treatment but remained above pretreatment level until 5.5 h after treatment withdrawal; the maximum reached was about half that in normal ovulation cycles.(ABSTRACT TRUNCATED AT 400 WORDS)

There have been several approaches to the control of the timing of the oestrous cycle and ovulation in dairy cattle in the last three decades. The first phase involved the use of progestins which were administered in various forms for prolonged periods. Although the timing of oestrus was controlled in most animals after withdrawal of the treatment, this control was not very precise and pregnancy rates from insemination at the first oestrus after treatment were reported to be below normal. Attempts were then made to combine short-term progestin treatments with oestrogens as luteolytic agents to gain better control of the timing of oestrus and ovulation. These studies resulted in some cases in better synchronization of oestrus and improved pregnancy rates. The discovery that prostaglandin F2 alpha (PGF2 alpha) and its synthetic analogue, cloprostenol were potent luetolytic agents in the cow led in the past decade to the use of these agents for oestrus and ovulation control in cattle. Prostaglandins for this purpose are ineffective in anovulatory cows, in cows with deficient luteal function and in the first 5 days of the oestrus cycle when a new corpus luteum is being formed. This limitation in their use has encouraged investigations into the combined use of short-term progestin treatment with prostaglandins to give more effective control of the timing of oestrus and ovulation and to avoid the adverse effects on fertility of long-term progestin treatment. Short-term progestin treatment combined with prostaglandins should mean that fewer cows would have ovulation suppressed for long periods and fertility of treated cows should be improved. A comparison of three procedures of ovulation control and fertility results shows the short-term progestin treatment combined with prostaglandin to be the most effective.

To compare the effects of PGF2α (dinoprost tromethamine) and D-cloprostenol in a two-dose protocol for estrus synchronization in hair sheep during breeding season in Yucatán, México, two experiments were conducted. In experiment 1, 61 cyclic hair sheep were divided into two groups: G1 (control n = 30), two doses of 50 μg of dinoprost tromethamine IM with 12 days between applications, and G2 (n = 31), two doses of 50 μg of D-cloprostenol IM at the same time interval. For determination of progesterone levels, 16 ewes from each group were randomly selected. In experiment 2, 70 cyclic hair sheep were assigned at the same treatments (G1 and G2, n = 35) and 48 h after the second application, the ewes in estrus were detected by two vasectomized rams. Sheep with detected estrus were inseminated, and 45 days after, pregnant animals were identified by ultrasonography. An exact Fisher's test was performed for the analysis of ewes in estrus (experiments 1 and 2) and number of pregnant ewes (experiment 2); for the comparison of time between end of treatment-estrus presentation, a survival analysis was used. Duration of estrus in hours was analyzed using a generalized mixed model (GLM) ANOVA whereas plasma progesterone concentrations were analyzed by non-linear regression. There were significant differences (P < 0.05) in the proportion of ewes in estrus upon treatments (G1, 57% vs G2, 87% and G1, 37.1% vs G2, 65.7% in experiments 1 and 2, respectively), and between the end of treatment-onset estrus interval (P < 0.01), survival curves showed the highest number of sheep in estrus between 40 and 48 h (G1, 43.7 + 8.05 h vs G2, 42.9 + 6.7 h, experiment 1). There were no significant differences (P>> 0.05) in duration of estrus (G1, 42 + 6.1 h, vs G2, 41.1 + 11.2 h, experiment 1) and pregnancy in the ewes that presented estrus, and were inseminated (G1, 38.4% vs 52.1%, experiment 2). With regard to concentrations of progesterone, significant differences (P < 0.01) were found between treatments, and progesterone levels before the second application of D-cloprostenol were higher. In consideration of the results, it can be concluded that in a two-dose protocol of a luteolytic agent, more ewes presented estrus in response to D-cloprostenol compared to dinoprost tromethamine with similar pregnancy rates.

The combination of a dopamine agonist, cabergoline, and a synthetic analogue of prostaglandin F2 alpha, cloprostenol, was used to induce termination of pregnancy from day 25 after the estimated luteinising hormone surge (day 27 +/- 4 after the first mating) in five mature beagle bitches. Cabergoline was administered orally at 5 micrograms/kg daily and cloprostenol was injected subcutaneously at 1 microgram/kg every other day. Treatment efficacy, in terms of pregnancy termination, was 100 per cent. Termination always took place by resorption of the fetuses. No side effects were observed. A mean of three injections of cloprostenol and nine days of cabergoline treatment was necessary to eliminate all signs of gestation. Termination was in each case accompanied by a decline in plasma progesterone (to less than 1 ng/ml) within 72 hours of initiation of treatment. In a control group of five, untreated bitches, plasma progesterone remained elevated throughout a corresponding period (from day 25 to day 50 after the estimated luteinising hormone surge). In the treated group, interoestrous intervals (98 +/- 41 days) were reduced, compared with previous cycles (194 +/- 9 days) or with those of the control animals (205 +/- 37 days). It is concluded that the combination treatment with the anti-prolactinic agent, cabergoline (5 micrograms/kg/day), and the synthetic prostaglandin F2 alpha, cloprostenol (1 microgram/kg/two days), is an easy, practical, reliable and safe method to terminate pregnancy near and before mid-gestation in dogs.

Myometrial samples were biopsied from pigs at early pregnancy, within 12 h after initiated abortion and at first dioestrus post-abortion. Abortion was induced either with an isolated gram-negative bacterial endotoxin or the prostaglandin (PG) F2 alpha analog cloprostenol. The tissues were quantitatively examined for gap junctions in electron micrographs. Very small numbers of gap junctions were present between smooth muscle cells in myometria at 24-27 days of pregnancy. The cell-to-cell junctions increased both in number and size at abortion, irrespective of the agent used as abortifacient. A low number of gap junctions were recorded in samples obtained after reinitiation of the oestrous cycle. The plasma levels of oestradiol-17 beta were low at the three biopsy procedures while the increased numbers of gap junctions at abortion occurred when significantly high levels of PGF2 alpha concomitantly with withdrawal of progesterone were determined in circulating blood plasma. It remains therefore unclear, which role do oestrogens play in the synthesis of gap junctions at induced abortion.

Equine pituitary extract (EPE) has been reported to induce heightened follicular development in mares, but the response is inconsistent and lower than results obtained in ruminants undergoing standard superovulatory protocols. Three separate experiments were conducted to improve the ovarian response to EPE by evaluating: (1) effect of increasing the frequency or dose of EPE treatment; (2) use of a potent gonadotropin-releasing hormone agonist (GnRH-a) prior to EPE stimulation; (3) administration of EPE twice daily in successively decreasing doses. In the first experiment, 50 mares were randomly assigned to one of four treatment groups. Mares received (1) 25 mg EPE once daily; (2) 50 mg EPE once daily; (3) 12.5 mg EPE twice daily; or (4) 25 mg EPE twice daily. All mares began EPE treatment 5 days after detection of ovulation and received a single dose of cloprostenol sodium 7 days postovulation. EPE was discontinued once half of a cohort of follicles reached a diameter of >35 mm and hCG was administered. Mares receiving 50 mg of EPE once daily developed a greater number (P = 0.008) of preovulatory follicles than the remaining groups of EPE-treated mares, and more (P = 0.06) ovulations were detected for mares receiving 25 mg EPE twice daily compared to those receiving either 25 mg EPE once daily and 12.5 mg EPE twice daily. Embryo recovery per mare was greater (P = 0.05) in the mares that received 12.5 mg EPE twice daily than those that received 25 mg EPE once daily. In Experiment 2, 20 randomly selected mares received either 25 mg EPE twice daily beginning 5 days after a spontaneous ovulation, or two doses of a GnRH-a agonist upon detection of a follicle >35 mm and 25 mg EPE twice daily beginning 5 days after ovulation. Twenty-four hours after administration of hCG, oocytes were recovered by transvaginal aspiration from all follicles >35 mm. No differences were observed between groups in the numbers of preovulatory follicles generated (P = 0.54) and oocytes recovered (P = 0.40) per mare. In Experiment 3, 18 mares were randomly assigned to one of two treatment groups. Then, 6-11 days after ovulation, mares were administered a dose of PGF2, and concomitantly began twice-daily treatments with EPE given in successively declining doses, or a dose of PGF2alpha, but no EPE treatment. Mares administered EPE developed a higher (P = 0.0004) number of follicles>> or = 35 mm, experienced more (P = 0.02) ovulations, and yielded a greater (P = 0.0006) number of embryos than untreated mares. In summary, doubling the dose of EPE generated a greater ovarian response, while increasing the frequency of treatment, but not necessarily the dose, improved embryo collection. Additionally, pretreatment with a GnRH-a prior to ovarian stimulation did not enhance the response to EPE or oocyte recovery rates.

The aim of this study was to determine and compare the concentrations of total (T) and free (F) fractions of thyroid hormones (T(3)-triiodithyronine and T(4)-thyroxin) in peripheral circulation and follicular fluid of cows in relation to ovarian follicular status in vivo (Experiment 1), and in the follicles from the slaughterhouse ovaries (Experiment 2). In Experiment 1, estrus was synchronized in 15 cows using two Estrumate (cloprostenol sodium) injections (250 mg cloprostenol intramuscular), the time of ovulation (Day 0) was confirmed by ultrasonography, and ovarian antral follicles were ablated on Day 5. The ensuing superovulatory treatment consisted of eight Folltropin-V injections (50 mg intramuscular) administered twice daily from Day 6 to Day 9, followed by two injections of Estrumate (Day 10 am and pm) and a single dose of Lutropin Alfa (Day 11; 750 IU intramuscular). On Day 5, both TT(3) and FT(3) concentrations were greater (P < 0.05) in serum than follicular fluid from dominant (DFs) or subordinate antral follicles (SFs), and TT(4) concentrations were greater (P < 0.05) in DFs compared with SFs. Serum concentrations of FT(4) were greater (P < 0.05) on Day 12 than on Day 5, and TT(4) concentrations in follicular fluid collected on Day 12 were higher than those in DFs and SFs on Day 5. In Experiment 2, there were no differences (P>> 0.05) in thyroid hormone concentrations between the largest and all remaining antral follicles visible on the surface of the ovary (n = 20 ovaries). We concluded that: (i) physiological status of bovine antral follicles (i.e. dominant versus subordinate) may impinge on the accumulation of TT(4) in follicular fluid; and (ii) hormonal ovarian superstimulation increases circulating levels of FT(4) and follicular fluid content of TT(4).

OBJECTIVE

Cloprostenol sodium salt (referred as cloprostenol) may be used for the synchronization of estrous cycles in farm animal species. Cyclodextrins (CDs) have potential as drug delivery systems through the formation of inclusion complexes between CDs and drugs. This is the first study of the inclusion complex of cloprostenol with beta-cyclodextrin (beta-CD) in aqueous solution using NMR and 3D molecular dynamics simulations.

METHODS

1D proton NMR spectra of beta-CD, a complex of cloprostenol with beta-CD, and cloprostenol in D(2)O were assigned and confirmed. The cross relaxation interactions from ROESY were used as constraints for 3D molecular modeling studies.

RESULTS

In the 2D ROESY of the complex, cross-peaks were observed between the aromatic protons of cloprostenol and protons of the beta-CD as well as between aliphatic protons and protons of the beta-CD. The stoichiometry of the complex was found that beta-CD forms a 1:1 inclusion complex with cloprostenol. The association constant K was 968 +/- 120 M(-1) at 298 K.

CONCLUSIONS

Aromatic side and/or aliphatic side chains of the cloprostenol is included in the beta-CD while aliphatic side and/or aromatic side chains wraps around beta-CD, respectively. The molecular modeling also confirms that beta-CD forms a 1:1 inclusion complex with cloprostenol.

The oestrous response, interval and conception rates were studied after synchronization with a prostaglandin analogue (cloprostenol) and artificial insemination (AI) performed at different times in 50 Zebu (Bos indicus) and 83 Baoulé (Bos taurus) cattle indigenous to Burkina Faso. The overall proportion of cows responding to synchronization was 70% (93/133). Although the response was higher for the Baoulé cattle, at 73.5% (61/83), than for the Zebu, at 64% (32/50), the difference was not statistically significant (p>> 0.05). The mean oestrous interval from treatment to the onset of oestrus (TOI) was shorter in the Zebu (54.1 h, SD 6.7) than in Baoulé (65.2 h, SD 12.9) cattle (p < 0.001). Of the Zebu (n = 32) that responded, 65.7% presented oestrus over a period of 12 h ranging from 48 h to 60 h after treatment. For the Baoulé cows, the highest proportion of animals in oestrus over a period of 12 h was 41% between 60 h and 72 h after treatment. The frequency distribution of onset of the oestrus indicated that up to 64.5% of the Zebu and 79.5% of the Baoulé cattle showed onset of oestrus during the daytime. For Zebu and Baoulé cows inseminated 13 h or 18 h after the onset of oestrus, conception rates were 56% and 57% (p>> 0.05) and 33% and 64% (p < 0.05), respectively. Based on these findings, it appears that the oestrous response to synchronization was adequate for both Zebu and Baoulé cattle and that the time to onset of oestrus varied according to genotype. It was also concluded that conception rates were satisfactory for both genotypes but that, for Baoulé cattle, AI performed 18 h after oestrus significantly increased conception rates compared to AI at 13 h after oestrus.

Cloprostenol, a prostaglandin F2-alpha analogue, used in the Czechoslovak preparation Oestrophan ing. Spofa was tested by a new nontraditional use. The effect of cloprostenol use on reproductive parameters of sows after piglet weaning was followed in a set of 456 experimental and 434 control sows. The effect of single intramuscular instillation of cloprostenol was tested in five partial observations: to multiparous sows at a dose of 175 micrograms on the day of weaning (experimental group no. 1), on day 1 after weaning (group no. 2), 500 micrograms on day 1 after weaning (group no.3), to primiparous sows at a dose of 500 microgram on day 1 after weaning (group no. 4). The treatment used in group no. 4 was also applied to 42 primiparous sows kept on a farm with regular occurrence of post-weaning anoestria of sows (experimental group no. 5). These parameters were evaluated: dynamics of oestrus onset within five, and/or ten, days after weaning, average length of the weaning--first insemination interval, conception rate after the first insemination in dependence on terminated deliveries and parameters of piglet litter. Cloprostenol application did not have a statistically significant effect on the evaluated reproductive parameters. The percentage of multiparous, and/or primiparous, sows in which the oestrus onset was not detected by the 10th day after weaning, did not show any large differences in the various experimental and control groups (17.09 vs. 16.55%, 23.53 vs. 32.56%, 13.66 vs. 18.13%, 29.54 vs. 30.30%; P>> 0.05). On the farm with regular occurrence of post-weaning anoestria there were 73.81% of primiparous sows with oestrus onset after cloprostenol instillation and 71.43% primiparous sows without treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

OBJECTIVE

The effects of various parturition controlling measures in sows on the relevant parameters for parturition were investigated.

METHODS

A total of 1975 study animals were divided into five groups: control group: A (n = 710); trial groups: B (n = 719), C (n = 180), D (n = 175), E (n = 191). The control group (A) included sows that spontaneously farrowed until day 114 of gestation. The remaining sows were administered a PGF2α-analogue (175 µg cloprostenol) on day 114. All sows that farrowed within 24 hours after prostaglandin-medication were summarised in trial group B. Dams that did not farrow until day 115 were either administered oxytocin (20 IU i. m., group C) or carbetocin in two different doses (70 µg, group D or 35 µg, group E). The sows were monitored during the peripartal period over 24 hours.

RESULTS

83.8% of the farrowings were without any complications. The percentage of dystocia varied between the individual groups. Given a complication-free farrowing the expulsion stage began 13.0 hours (group B), 2.4 hours (group C), 1.6 hours (group D) and 1.4 hours (group E) after medication. The expulsion interval of the farrowing of two piglets decreased from 21.1 minutes with spontaneous farrowings (group A) to 18.6 minutes (group E) as a result of the administration of 35 µg carbetocin. The rate of stillborn piglets as well as the incidence of puerperal disorders and the losses of the suckling piglets also gradually, partly even significantly (p ≤ 0.05) decreased from group A to E.

CONCLUSIONS

The results of this study show that the use of the long-acting oxytocin carbetocin has advantages compared to oxytocin (e. g. shortened duration of birth, reduction of stillbirths). The tested dosages of carbetocin (35 µg or 70 µg) proved to be equally effective. Administration of the lower dose is recommended, since this reduces use of the active ingredient.

As part of a larger project investigating the development and heritability of choanal atresia glama), it was necessary to develop a protocol for aborting llamas at various stages of gestation. Twenty-seven animals between 4 and 7 mo of gestation were successfully aborted a total of 53 times following two 250 microg intramuscular injections of cloprostenol at 24 h intervals. Abortion was induced once in 10 animals and multiple times (range 2 to 5) in 17 animals. Twenty-four animals (45.2%) aborted 3 d following the first injection, with 20 animals (37.7%) aborting 4 d post prostaglandin administration. Other animals aborted at 2 d (n=6, 11.3%), 5 d (n=2, 3.8%), and 7 d (n=1, 1.9%) following drug administration. Forty-nine (92.5%) of the abortions occurred following a single series of injections, while 4 animals (7.5%) aborted following a second series of injections. No confirmed pregnant animals failed to abort following the second series of cloprostenol injections. Conception rates in animals rebred 2 to 4 wk following an abortion were comparable to those of untreated animals in the research herd. Unlike the severe hypertension and death that has been reported following dinoprost tromethamine administration in the llama, no adverse reactions were observed in this study following cloprostenol administration. The results demonstrate that llamas can be safely and effectively aborted up to 7 mo of gestation (normal full term gestation = 342 +/- 10 days) without adverse effects on subsequent fertility.