Twenty-five Thoroughbred jumper geldings suffered back soreness with poor performance and 5 control horses were assessed by archived computer data, clinical examination and laboratory analyses of complete blood picture, serum enzymes and cortisol level, before and after cloprostenol-aquapuncture. The 25 diseased horses before therapy showed significant increases in AST and CPK with clinical pains scored mild in 15 horses, moderate in 9 horses and severe in one horse, without changes in the hormonal and hematological data. After therapy, they responded by an increase of heart rate (57.8±4.3)bpm, body temperature (38.5±0.7)^οc, respiration rate (28.3±2.1)bpm and CRT (1.0±0.0). On the 2^nd day, a significant decrease in the mean levels of AST and CPK (P=0.001) was detected; while on the 4^th day, they mimed the level of the 5 controls, and on the 6^th day showed a significant decrease (P=0.002). The serum cortisol level showed a significant increase on the 6^th day of treatment (P=0.013). The blood picture showed significant increases in RBCs, MCV, PLT, WBC, HGB, MCH, MCHC, MPV, PDW, LYMPH, PCT, LPCR (P<0.05) and non-significant changes in HCT, GRAN, MID. The improved blood parameters, enzymes, hormones, and performance progress after cloprostenol-aquapuncture proved its effectiveness for treating back soreness in athletic horses.

Thirty-two beef heifers were induced to superovulate by the administration of follicle stimulating hormone-porcine (FSH-P). All heifers received 32 mg FSH-P (total dose) which was injected twice daily in decreasing amounts for 4 d commencing on Days 8 to 10 of the estrous cycle. <em>Cloprostenol</em> was administered at 60 and 72 h after the first injection of FSH-P. Heifers were observed for estrus every 6 h and were slaughtered at known times between 48 to 100 h after the first <em>cloprostenol</em> treatment. The populations of ovulated and nonovulated follicles in the ovaries were quantified immediately after slaughter. Blood samples were taken at 2-h intervals from six heifers from 24 h after <em>cloprostenol</em> treatment until slaughter and the plasma was assayed for luteinizing hormone (LH) concentrations. The interval from <em>cloprostenol</em> injection to the onset of estrus was 41.3 +/- 1.25 h (n = 20). The interval from <em>cloprostenol</em> injection to the preovulatory peak of LH was 43.3 +/- 1.69 h (n = 6). No ovulations were observed in animals slaughtered prior to 64.5 h after <em>cloprostenol</em> (n = 12). After 64.5 h, ovulation had commenced in all animals except in one animal slaughtered at 65.5 h. The ovulation rate varied from 4 to 50 ovulations. Approximately 80% of large follicles >> 10 mm diameter) had ovulated within 12 h of the onset of ovulation. Onset of ovulation was followed by a dramatic decrease in the number of large follicles >> 10 mm) and an increase in the number of small follicles (</= 5 mm). These data indicate that ovulations in superovulated beef heifers occur over 12 h and commence approximately 24 h after the onset of estrus and 22 h after the peak of LH.

The time of ovulation was determined in heifers following two injections 11 days apart of 500 microgram of cloprostenol by recovery of reproductive tracts at slaughter. Ovulation had not begun by 72 hours while 31%, 61% and 95% had ovulated by 78, 92 and 96 hours respectively after the second injection of cloprostenol. Injection of synthetic LH-releasing factor (GnRH) given 48 hours after cloprostenol significantly hastened the time of ovulation in animals slaughtered at 78 hours after the second cloprostenol injection. Insemination of heifers at 48, 60 or 72 hours resulted in lower fertility than two inseminations at 60 and 72 hours or at 48 and 72 hours after treatment. Controlling the time of ovulation with GnRH did not increase the fertility following a single insemination 71 hours after the treatment with cloprostenol.

A PGF-2 alpha analogue (cloprostenol) was injected into 9 cows to synchronize oestrus. The cows were placed with or without a bull in a free-stall in groups of 3 at 46 h after the injection. Sexual behaviour was observed and serum LH concentrations were measured during the next 34 h. The bull ejaculated with the cows in regular sequence and did not return to cows after an ejaculatory series was completed. The mating behaviour of the bull was closely related to the LH surge of the cows.

The effects of potassium nitrate were investigated on ovarian activity, especially on ovarian activity, especially on follicle ripening and ovulation, conception rate and progesterone levels in the milk of cows with cloprostenol-induced oestrus (Oestrophan Spofa) at a rate of 500 micrograms i.m. Potassium nitrate was administered at an amount of 150 g per head/day, and this amount increased by 50 g every other fortnight to the total rate of 300 g per head/day. In a group of 11 cows exposed to potassium nitrate load, clinical examination of ovaries on day 8 after oestrus revealed the presence of CL in seven cows (63.6%), persisting follicles in two cows, and two cows did not have any CL or follicles (Tab. I). After the first insemination three cows got in calf (27.3%), and after all inseminations it was 10 cows in total (90.9%) on average in 24.4 days after cloprostenol administration, with SP 96.7 days and insemination index 1.7. No ovulation disorders were found in the control group. All five cows got in calf after the first insemination in three days after cloprostenol administration with SP 61.5 days and insemination index 1.0 (Tab. II). The progesterone levels in milk were 22.3 and 21.1 ng/ml before the second administration of cloprostenol, 2.7 and 2.1 ng/ml in oestrus and at the time of A.I., and 16.6 in eight days after insemination in cows exposed to nitrate load, and finally 21.7 ng/ml in the control group (Tab. III). Ovulation disorders were easily detectable by a clinical check of ovaries on day 8 after oestrus.(ABSTRACT TRUNCATED AT 250 WORDS)

There was investigation of whether there were ovulations from co-dominant follicles following eCG administration. In all experiments, there was GnRH injection and CIDR insertion on day 0 (D0), CIDR withdrawal on D8, and cloprostenol administration on D8 (Exp. I and II) or D7 and D8 (Exp. III). Females in the control group were not administered any further treatment. Females in other group(s) were treated with eCG (500 IU) on Day 2 in Exp. I, Day 2 (eCG-2) or 8 (eCG-8) in Exp. II and Day 2 (eCG-2) or Days 2 and 6 (eCG-2-6) in Exp. III. Ovaries were examined using ultrasonography. In Experiments I and II, females had follicle emergence on Day 2. At the time of CIDR removal, more eCG-treated heifers (8/9; Exp. I) and cows (5/6; eCG-2; Exp. II) had co-dominant follicles compared to those in the control group (P < 0.05). Occurrence of ovulations from co-dominant for individual cows was minimal. In Experiment III, the time period from CIDR removal to estrus in cows treated with eCG-2 (68 ± 13 h) was longer compared to cows in the control (37±2 h) and eCG-2-6-treated group (38 ± 5 h; P < 0.05). There was a greater proportion of heifers having ovulations and thus greater progesterone concentration in the eCG-2-6 than eCG-2 group (P < 0.05). Administering eCG twice 4 days apart with the initial administration being two days after GnRH administration, at the time of follicle wave emergence, could induce growth of and ovulation from co-dominant follicles and enhance progesterone production in cattle.

Keywords: Co-dominant follicles; Double ovulation; eCG.

To test whether inhibin A assays can be used for the prediction of yields in embryo programmes in goats, 50 does were treated with 45 mg FGA sponges (Chronogest) for 16 days plus a single dose of 100 microg i.m. cloprostenol on Day 14, just before the start of administration of eight doses of 1.25 ml of Ovagen twice daily for 4 days. At first FSH injection, the number and size of all follicles>> or =2 mm was assessed by transrectal ultrasound and plasma inhibin A levels were measured by specific dimeric assay. There was a positive correlation between number of follicles>> or =6 mm (8.8 +/- 0.5) and inhibin A levels at first FSH dose (193.2 +/- 14.5 pg/ml, P<0.05). The mean number of corpora lutea on Day 7 after sponge removal was related to the total number of follicles with a diameter of 2-6 mm at the onset of the FSH treatment (15.3 +/- 0.7, P<0.05). The total number of embryos recovered was related to the number of follicles with 4-6 mm in size (6.2 +/- 0.5, P<0.05) and to the inhibin A levels at first FSH dose (P<0.05). These results suggest that follicles>> or =4 mm are the source of inhibin prior to FSH stimulation and are the main source of oocytes resulting in the number of viable embryos recovered after a superovulatory treatment. Hence, the response to superovulatory treatments in goats in terms of the number of embryos can be predicted from either the population of follicles determined by ultrasound or the plasma inhibin A levels at start of the superovulatory FSH treatment.

A total of 24 non-antibiotic compounds were tested for their antimicrobial activity against Escherichia coli, Klebsiella pneumoniae (ATCC) and an MDR strain of Acinetobacter baumannii using an agar well diffusion assay. To study additive effects, 100 µl of each antibiotic and 50 µl of each non-antibiotic were used. Cloprostenol was the only non-antibiotic that showed antibacterial activity against all bacterial strains. Cloprostenol had an additive antimicrobial effect with the tested antibiotics against the MDR A. baumannii strain.

Progestogen pretreatment and introduction of rams were used to prepare 432 Rasa aragonesa ewes for synchronization of estrus with prostaglandin (PG) during anestrus. The experiment was a 3 x 3 x 2 factorial with lactation status, ram/progestogen treatment and treatment with pregnant mare's serum gonadotropin (PMSG; 250 IU) at injection of PG as main effects. At ram introduction (Day 0), ewes were dry (Group 1), weaned (Group 2) or suckling a lamb (Group 3). They received either norgestomet implants for 12 d (Days -12 to Day 0 (Group A), ram introduction for 12 d (Days 0 to 12) (Group B) or both (Group C). Half the ewes received PMSG with PG (100 mug Cloprostenol) on Day 12. Pregnancy rate was higher at first service in dry (Group 1; 42%) than in recently-weaned ewes (Group 3; 24% and Group 2; 31%; P<0.01). Occurrence of estrus and conception and pregnancy rates to first service were higher (P<0.01) in ewes previously exposed to rams (Groups B and C) than in ewes treated only with progestogen (Group A). There were no effects of PMSG, no interactions among the three variables and no differences in prolificacy (1.12 at first service).

Human chorionic gonadotrophin (hCG) plus PGF2 alpha was compared with GnRH plus PGF2 alpha for estrus synchronization of dairy cows. There were 3 treatments: GnRH analog (Buserelin, 12.6 micrograms) plus PGF2 alpha analog (Cloprostenol, 150 micrograms) 6 d later (GnRH + PGF[Day 6]); hCG (2000 IU) plus PGF2 alpha 9 d later (hCG + PGF[Day 9]); and hCG plus PGF2 alpha 6 d later (hCG + PGF[Day 6]). Treatment occurred either Days 55 to 90 or Days 91 to 135 post partum. For responses during the first 10 d after PGF2 alpha administration, estrus synchronization (P = 0.24), efficacy (percentage of treated pregnant; P = 0.20) and conception (percentage of inseminated pregnant; P = 0.23) rates were not different among the 3 treatments. Cows treated between Days 55 and 90 had a higher rate (P < 0.05) of detected estrus during this period (69% for GnRH + PG [Day 6], 70% for hCG + PGF[Day 9] and 72% for hCG + PGF[Day 6]) compared with cows treated between Days 91 and 135 (52% for GnRH + PGF[Day 6], 50% for hCG + PGF[Day 9] and 57% for hCG + PGF[Day 6]). Efficacy of treatment was higher (P < 0.05) in animals treated between Days 55 and 90 (54% for GnRH + PGF[Day 6], 56% for hCG + PGF[Day 9] and 63% for hCG + PGF [Day 6]) compared to animals treated between Days 91 and 135 (36% for GnRH + PGF[Day 6], 35% for hCG + PGF[Day 9] and 47% for hCG + PGF[Day 6]). There were no significant differences in conception between Days 51 and 90 and Days 91 and 135. The interval between parturition-first AI with conception was significantly (P < 0.001) shorter in GnRH + PGF (Day 6; 106 d), hCG + PGF (Day 9; 109 d) and hCG + PGF (Day 6; 103 d) treated cattle than in 106 untreated animals (136 d). Thus, GnRH plus PGF2 alpha or hCG plus PGF2 alpha treatments elicited similar effects in estrus synchronization, treatment efficacy, and conception rate in post-partum dairy cows.

We studied the influence of cloprostenol (CIPG) 200 micrograms/Kg i.p. (a synthetic analogue of PGF2-alpha) and of imidazol 70 mg/Kg i.p. (a selective inhibitor of thromboxane synthetase) on fasting glycemia and on hypoglycemia induced by Actrapid insulin 0.5 UI/Kg i.p. to rats (male adults). The determinations of glycemia were made 60 minutes and 3 hours after the administration of the substances. The tests were made in groups of 20 animals which were not fed 14 hours before the experiment, but were not deprived of water. The results were interpreted statistically by means of the "t" test. The data obtained show that CIPG 200 micrograms/Kg i.p. is a significant hyperglycemic icosanoid (statistically p less than 0.01) both in the case of fasting glycemia and in the case of insulin hypoglycemia. The hyperglycemic effect was stronger at 60 min. Imidazol does not modify significantly either glycemia or insulin hypoglycemia, which pleads for a more reduced implication of thromboxanes in the regulation of glycemia in comparison to the prostaglandins.

The objectives of this study were (1) to assess the effect of purulent vaginal discharge (PVD) on reproductive performance using a 4-point vaginal discharge score (VDS) and (2) to evaluate the effect of PGF2α treatment in cows with PVD on reproductive performance. Holstein cows (n = 2,473) from 1 commercial dairy farm had their vaginal discharge scored at 32 ± 3 d in milk (DIM) using a 4-point scale. Cows were also scored for body condition score and had their ovaries examined using transrectal ultrasound. A VDS-2 or greater was used to define PVD. Cows with PVD were assigned to receive 2 doses of 500 µg of PGF2α analogue (n = 277; Cloprostenol; PGF Veyx forte, Veyx Pharma Ltd., Schwarzenborn, Germany) 14 d apart (odd ear tag number) or remained untreated (n = 272; even ear tag number). All cows not detected in estrus at 90 ± 3 DIM were enrolled into a timed artificial insemination (AI) protocol. The effect of VDS and the effect of PGF2α in cows with PVD on reproductive performance were evaluated separately. First service conception risk (FSCR), time to first AI, and time to pregnancy were used as indicators for reproductive performance. Data were analyzed with Cox's regression and mixed logistic models. The prevalence of PVD was 22.2% (548/2,473). We detected an interaction of parity and VDS for FSCR and time to pregnancy. In primiparous cows, VDS had no effect on FSCR and time to pregnancy. In multiparous cows, VDS had an effect on FSCR and time to pregnancy. Multiparous cows having a VDS-2 or a VDS-3 had decreased odds of pregnancy at first AI compared with cows having a VDS-0. Multiparous cows with VDS-1 or VDS-3 had a decreased hazard of conceiving within 200 DIM. The treatment effect of PGF2α was conditional on parity. In primiparous animals with PVD without a corpus luteum present at 32 DIM, treatment with PGF2α reduced FSCR. Irrespective of the presence of a corpus luteum, treatment with PGF2α decreased the hazard of conceiving within 200 DIM in primiparous cows. Although multiparous cows with PVD treated with PGF2α had increased odds of pregnancy at first AI, no treatment effect was observed on the hazard of conceiving within 200 DIM. Our results do not support the blanket use of PGF2α as a treatment option in postpartum dairy cows having PVD.

The present study aimed to assess the efficacy of reduced doses of cloprostenol for synchronizing estrus and ovulation in hair sheep. With the aim to evaluate the luteolytic activity of reduced cloprostenol doses, a first experiment was performed using a relatively large (group H: 126 microg; n=8), medium (group M: 68.25 microg; n=6) and small (group L: 38.5 microg; n=6) cloprostenol dose. Luteolysis was assessed at Days 3 and 6 after injection (Day 0) by progesterone concentrations (P(4)) and transrectal ultrasonography (US). In Experiment 2, sheep were randomly assigned to the same three doses to evaluate a protocol for estrous synchronization using two injections administered 9 days apart. A third trial was performed with ewes treated (9 days apart) with the large dose (H=126 microg; n=12) and with a small dose adjusted for facilitating volume management (LA=43.75 microg; n=12). Presence of estrous cycling was determined in all the ewes by US and P(4) assay, at Days -9, -6, -2, 0 (Day of second cloprostenol injection), 8 and 11. Bleeding and US were done every 4h from 16 h of the beginning of the estrus during the third trial to assess the preovulatory LH surge and timing of ovulation. Additionally, blood samples were drawn at Days 0, 1, 2 and 3 to assess estradiol (Experiments 2 and 3) and P(4) (Experiment 2) concentrations during the ovarian follicular phase. In all experiments, percentage of animals showing luteolysis, preovulatory follicular dynamics and function and percentage of ewes showing behavioral estrus in response to treatment was similar among groups. Timing of estrus for group H was earlier than group L (28.6+/-1.8h compared with 37.1+/-2.4h; P<0.05). In the third trial, the preovulatory LH peak was higher in the LA group than group H, in terms of maximum mean concentration during the surge (27.7+/-1.8 ng/mL compared with 21.3+/-2.2 ng/mL; P<0.05) and area under the curve (AUC; 183.4+/-12.7 ng/mL compared with 127.7+/-10.9 ng/mL; P<0.01). However, timing of ovulation was similar for H and LA groups. Thereafter, ovulation rate and luteal function at Day 11 were similar. Current results demonstrate that reduced doses of cloprostenol may be applied in a practical manner for reproductive management of sheep, with the additional advantage of reducing treatment costs.

The aim of the present study was to compare the clinical and endocrinological effects of four different treatments for the induction of abortion in bitches. For this purpose, 28 pregnant bitches between days 25 and 35 of gestation, were randomly assigned to four groups. In group I (n = 7), only aglepristone (AGL, 10mg/kg bw, two injections 24 h apart, s.c.) was administered. In group II (n = 7), AGL (as in group I), cabergolin (CAB, 5 μg/kg, daily p.o., until completion of abortion) and misoprostol (MIS, 200 μg for bitches with ≤ 20 kg bw, 400 μg for bitches with>> 20 kg bw, daily intravaginally, until completion of abortion) were administered. In group III (n = 7), AGL (as in group I) and MIS (as in group II) were administered. In group IV (n = 7) AGL, (as in group I) and cloprostenol (CLO, 1μg/kg bw, s.c., two injections 24 h apart with the AGL injections) were combined. In all groups, bitches were examined daily, clinically and ultrasonographically to monitor resorptions/abortions. To measure serum progesterone (P4) and total estrogen (TE) concentrations, blood samples were collected in all groups immediately after the first AGL administration and every other day until completion of abortion. No statistical differences were found between groups concerning the duration until completion of abortion following treatment (n.s.); however, in Group III, 6 d after the start of treatment all pregnancies were terminated whereas in Group I, II and IV, only 57.1% (4/7), 85.7 % (6/7) and 42.8 % (3/7) of pregnancies were terminated. In the latter groups, all pregnancies were terminated between days 8 and 10 after the start of treatment. In Group IV, P4 concentrations on days two and one before the beginning of abortion and the day the abortion started was significantly lower than in the other groups (P < 0.01). No statistical differences were found between groups for TE concentrations (P>> 0.05). In Groups I, II and III, no severe side effects occurred. Severe vomiting after each treatment and until the end of abortion was observed in Group IV only. In conclusion, only when a combination of AGL and MIS was used abortion was completed within 6 d in all bitches whereas the additional use of CAB did not improve the treatment.

OBJECTIVE

To determine some of the risk factors for cows not observed in oestrus within 35-42 days of an unsuccessful artificial insemination (AI; phantom cows), and the reproductive outcomes and effect of treatment of phantom cows.

METHODS

Over 2 years, in dairy herds from the Waikato (n=10) and Canterbury (n=4) regions of New Zealand, pregnancy diagnosis was carried out 35-42 days after AI on cows that had been inseminated in the first 3 weeks after the start of mating (PSM) but had not been seen returning to oestrus. Risk factors for phantom cows were analysed using a generalised linear mixed effect model. In Year 1, all phantom cows were left untreated. In Year 2, phantom cows were categorised as having a corpus luteum (CL) (CL+ n=120), or having ovarian follicles≥10 (n=101) or <10 (n=40) mm in diameter. Cows with a CL were treated with cloprostenol or untreated and placed with bulls. Cows with no CL received intravaginal progesterone (P4) for 7 days, with injection of gonadotrophin-releasing hormone (GnRH) on Days 0 and 9, and cloprostenol on Day 7 followed by AI. Pregnancy diagnosis of all cows took place 100-120 days after PSM and interval to conception and final pregnancy rate determined.

RESULTS

Overall, of cows inseminated in the first 3 weeks after PSM that did not return to oestrus, 610/6,734 (9.1%) were phantom cows. From the final multivariable analysis, treatment for anoestrus, BCS≤4.0 at mating, being 2 or >6 years of age, and pure-bred, and decreasing interval between calving and mating, until 98 days post calving, were associated with increased odds of being a phantom cow. Compared to all other groups of cows, phantom cows had a longer interval to conception (p<0.001) and a lower final pregnancy rate (p<0.001). Treatment of CL+ cows or cows with follicles≥10 mm did not affect reproductive outcomes (p>0.3). For cows with follicles<10 mm treatment decreased the final percentage not pregnant (3/27; 11%; p=0.01) and interval to conception (21 days; p=0.02) compared with controls (7/13; 54% and 37 days, respectively).

CONCLUSIONS

Risk factors for phantom cows were identified that could be manipulated to reduce the number of phantom cows in a herd, in particular increasing BCS. Treatment of the majority of phantom cows did not improve reproductive performance.

OBJECTIVE

To investigate the effect of targeted resynchronisation of cows treated for non-observed oestrus before the planned start of mating (PSM), that were not detected in oestrus or pregnant 23 days after treatment (phantom cows), on the proportion pregnant at 42 days after PSM and the end of mating.

METHODS

Farm staff from eight herds in two regions of the South Island of New Zealand identified 1,819 cows not showing oestrus by 10 days before PSM. These cows were treated with intravaginal progesterone for 7 days, and I/M gonadorelin 10 days and 1 day before PSM. Three days before PSM they were injected with cloprostenol and equine chorionic gonadotrophin, with fixed time artificial insemination (FTAI) at PSM. By 23 days after PSM, 1,218 cows had not returned to oestrus. Of these, 161 cows confirmed not pregnant by transrectal ultrasonography were randomly assigned to no treatment (control group; n=74) or were resynchronised 25 days after PSM using the same treatment programme as above, with FTAI 35 days after PSM (n=87). All cows that returned to oestrus were artificially inseminated until 42 days after PSM, when natural mating was used. All cows were examined using transrectal ultrasonography 80 to 90 days after PSM to confirm conception dates.

RESULTS

Of the 1,819 anoestrous cows treated before PSM, 526 (29 (95% CI=23.1-34.0)%) had not been observed in oestrus by 23 days after PSM and had not conceived, so were diagnosed as phantoms cows. For resynchronised cows, 42/87 (48 (95% CI=37.8-58.8)%) were pregnant by 42 days after PSM compared to 21/74 (28 (95% CI=18.1-38.7)%) control cows (p=0.009). At the end of mating 58/87 (67 (95% CI=56.6-76.7)%) cows in the resynchronised group were pregnant and 46/74 (62 (95% CI=50.9-73.2)%) in the control group (p=0.554). The hazard of conception from 21 to 42 days after PSM was 1.9 (95% CI=1.07-3.12) times greater for resynchronised than control cows (p=0.026).

CONCLUSIONS

In cows not observed in oestrus and treated before PSM, resynchronisation increased the proportion pregnant by 42 days after PSM.

CONCLUSIONS

The benefit of resynchronisation depends on the number of anoestrous cows before PSM and the number of phantom cows after PSM. However at the herd-level it is likely that providing advice to reduce the known risk factors for cows not being observed in oestrus before the PSM may well be more cost effective than identifying and treating a sub-population of phantom cows.

In the present study, 2.228 cycles of 180 Polo Argentino donor mares from an embryo transfer program in Argentina were examined to evaluate the effects of: (1) Interval from Prostaglandin F2alpha analog treatment to ovulation (ITO) on embryo recovery rate (ERR); (2) ITO on number of embryos per flushing (EPF); (3) ITO on multiple ovulation (MO) rate; (4) ITO from donor mare on pregnancy rate (PR) in recipient mares. Mares were inseminated with fresh semen from 31 fertile stallions in the induced estrus. Embryo flushing was performed 7-8 days postovulation. Following embryo flushing, donor mares were treated with prostaglandin F2alpha analog (cloprostenol 250 μg). The ERR increased along with the ITO (P = .01), with the lowest ERR (30.7%) for mares with an ITO of <4 days, and the highest (78.3%) in mares with an ITO of 10 days. The ITO from the donor mare in which the embryo was recovered did not have a significant effect on PR: ITO <6, 6 to 10, and >10 days were 74.6, 81.4, and 77.3%, respectively. The number of EPF and MO rate increased gradually along with the ITO (P < .05). In conclusion, the results of this study indicated that the ITO is positively correlated with the embryo recovery and the multiple ovulation rate.

Parturition was induced in 112 gilts and sows on day 111,, 112, and 113 of gestation by means of a single intramuscular injection of 175 mcg of a prostaglandin F2 alpha analogue (Cloprostenol, I.C.I 80996). No side effects were detected immediately after injection and the course of the induced parturition was normal. The interval between injection and parturition was approximately 28 hours. Induction of parturition on day 113 resulted in a significant shortening of this interval as compared with day 111, and 112. The average weights of the piglets at birth and at 5 weeks were within the normal range. The percentage of stillbirths and the loss of piglets up to weaning did not differ significantly between control and experimental groups. The practical applications of induction of parturition are discussed.

Summary Parturition was induced in 112 gilts and sows on day 111, 112, and 113 of gestation by means of a single intramuscular injection of 175 mcg of a prostaglandin F2α analogue (Cloprostenol, I.C.I. 80996). No side effects were detected immediately after injection and the course of the induced parturition was normal. The interval between injection and parturition was approximately 28 hours. Induction of parturition on day 113 resulted in a significant shortening of this interval as compared with day 111 and 112. The average weights of the piglets at birth and at 5 weeks were within the normal range. The percentage of stillbirths and the loss of piglets up to weaning did not differ significantly between control and experimental groups. The practical applications of induction of parturition are discussed.

Cloprostenol, a prostaglandin analogue, was administered intramuscularly to a total of 35 cycling buffalo cows and heifers in two doses, each of 0.5 mg, given 11 days apart. Out of five cows and 12 heifers subjected to observations after the second injection of cloprostenol (day 0), all except one heifer responded. Signs of oestrus were most marked on days 3 or 4. Eighteen treated heifers were kept with buffalo bulls for four days after the second injection while a control group of nine heifers was kept with bulls for 21 days. The first-service conception rate, diagnosed by rectal palpation at 60 days, was 33 1/3 per cent in both groups. Twelve treated heifers were artificially inseminated at 72 and 96 hours after the second injection of cloprostenol, using fresh semen diluted in egg yolk--citrate extender. The first service conception rate at 60 days was 30 per cent.