PGF2α Administration Research Articles

Effect of Parity and Milk Production on Conception Rate After Two Synchronization Protocols in Dairy Cows

Presynchronization strategies, such as Presynch- Ovsynch and Double- Ovsynch, increase fertility to timed artificial insemination (TAI) compared with Ovsynch alone; however, simpler presynchronization strategies could reduce costs and simplify reproductive management. Our objective in this study the effect of parity and average milk production on the conception rate after resynchronization with G6G protocol or Ovsynch protocol. Lactating Holstein cows (n = 100) divided into two groups (Ovsynch and G6G) cows in this group1 (n = 50) were received the following treatment sequence, 12 µg Buserelin on day zero, 500 µg IM of Cloprostenol on day seven, 12 µg Buserelin IM on day nine and received timed artificial insemination (TAI) 16 hours later. Group II (G6G): were received 500 µg IM Cloprostenol on day zero, 12 µg Buserelin on day two and six days later these cows received the Ovsynch as previously explained in the first group. Conception rate was (40 vs. 30 %) for G6G and Ovsynch protocol respectively primiparous cows, conception rate to G6G program was 46.15%, compared to 28.57% in cows synchronized with Ovsynch program. In Multiparous cows, the similar trend was observed but the difference was smaller (conception rate 37.8 vs. 30.55% in cows synchronized with G6G and with Ovsynch, respectively). In high producers, conception rate was numerically higher in the Ovsynch group (40%) compared to the G6G group (36%). While, in low producers, conception rate to G6G protocol (48%) tended (P = 0.07) to be higher than that to Ovsynch protocol (20%) in conclusion Administration of PGF2α 8 d before initiation of Ovsynch did not improve conception rate compared with the standard Ovsynch protocol

Effect of Intrauterine Infusion of Momordica Charantia L. on Oxidative Stress and Pregnancy Rate in Infertile Cows.

IntroductionThe effect of intrauterine administration of Momordica charantia L. (MC) extract on oxidative changes and pregnancy rate in infertile cows was investigated.Material and MethodsEndometrial smear specimens were taken from 40 cows with fertility problems for cytological examination, and the cows were randomly divided into two groups: group I (n = 20) was subjected to intrauterine administration of 40 mL (0.25 g/mL) of MC extract, group II (n = 20) was subjected to intrauterine administration of 40 mL of pure olive oil. Blood samples were taken starting from the day of administration of MC extract or olive oil (day 0) and then for three weeks at weekly intervals (days 7, 14, 21). Blood serum samples were evaluated for total antioxidant capacity (TAS), total oxidant level (TOS), oxidative stress index (OSI), lipid hydroperoxide (LOOH), and nitric oxide (NO) levels. In addition, on the 14th day following treatment, two doses of PGF2α were administrated to all cows at 14-day intervals. Following the second PGF2α administration, insemination and GnRH administration was performed at the 60th h after PGF2α treatment. Smear samples were stained with Giemsa and immunohistochemically to determine cytological changes and inflammatory status.ResultsAccording to cytological findings, subclinical endometritis was a prevalent disorder in cows with infertility problem (82.5%; 33/40). Additionally, 60.6% (20/33) of the cows with subclinical endometritis had acute inflammation, whereas remaining 13 cows had chronic endometritis. Of the cows with subclinical endometritis, 50% (8/16) and 35% (6/17) became pregnant in group I and II, respectively (P > 0.05). Although the oxidative stress parameters showed similarities between both groups (P > 0.05), there was a significant difference (P < 0.001) between the groups in terms of mean NO and LOOH levels (NO – 31.20 ± 11.38 vs 44.53 ± 11.50 μmol/L and LOOH – 1.22 ± 0.37 vs 1.89 ± 0.36 μmol/L).ConclusionThe obtained results indicated that MC administration, especially in the presence of active inflammation, may improve the pregnancy rate by positive reduction of oxidative changes.

Effects of oxytocin and PGF2α on uterine contractility in cows with and without metritis—An in-vitro study

The aim of this study was to investigate the effects of PGF2α and oxytocin in vitro on myometrial contractility in puerperal uteri. Thirteen puerperal uteri were removed and perfused after euthanasia of cows with (n=7) and without metritis (n=6). Measurement of uterine contractility was done using four piezoelectric crystals, which were implanted into the myometrium along the greater curvature of the uterine horn where fetal implantation occurred during the previous pregnancy. After 30min of equilibration, oxytocin (5 IU) or PGF2α (2.5mg Dinoprost) was administered randomly into both uterine arteries, and 30min later, the second administration of either oxytocin or PGF2α occurred. Treatment with oxytocin induced contractions in uteri with metritis and uteri without metritis (P<0.05). In uteri with metritis, greater uterine contractions occurred after stimulation with oxytocin than in uteri without metritis (P<0.05). Treatment with PGF2α did not (P>0.05) result in increased contractions in the uteri without metrtitis, however, induced an initial decrease in contractions followed by an increase (P<0.05) in contractions in uteri with metritis. Myometrial and endometrial gene expression of PGF2α (FPR) and oxytocin receptor (OTR) was greater (P<0.05) in uteri with metritis than in uteri without metritis. The results suggest that oxytocin, but not PGF2α, is an effective uterotonic drug in puerperal cows. Uteri in which metritis was diagnosed contracted more strongly after treatment with oxytocin than uteri in which metritis was not diagnosed. This effect was paralleled by greater gene expression of OTR as well as FPR in uteri with metritis compared with uteri in which metritis was not diagnosed.

Effect of GnRH on ovulatory response after luteolysis induced by two low doses of PGF2α in lactating dairy cows

This study investigated the effect of gonadotropin-releasing hormone (GnRH) on ovulatory response after complete luteolysis induced by two low doses of prostaglandin (PG)F2α in lactating dairy cows. Cows (n = 18) ranging between 45 and 65 days in milk were recruited for synchronization by a modified Ovsynch-48 protocol (GnRH-7 days-375 μg PGF2α-1 day-250 μg of PGF2α-1 day-GnRH) over a total of 23 estrous cycles. Synchronized cows (n = 16) were randomly assigned to GnRH and Saline groups in stage 1 of the experiment after 9–10 days of ovulation in synchronization. On days 0 and 1 (day 0 = first PGF2α administration), cows were treated with 375 and 250 μg PGF2α, respectively. On day 2, cows in the GnRH and Saline groups were administered 250 μg GnRH or 2.5 mL of 0.9% saline, respectively. Serum progesterone (P4) levels were measured and changes in the corpus luteum (CL) were ultrasonically monitored daily from day 0–3 to assess complete luteolysis. Preovulatory follicle diameter and ovulatory response were evaluated by ultrasonography. In stage 2, cows were treated in a manner converse to that in stage 1. The synchronization rate was 69.6% (16/23). In stages 1 and 2, cows showed complete luteolysis with P4 concentration <1 ng/mL or remaining CL area <50%. Average ovulation time was 29.3 ± 0.5 h, which mostly occurred between 28 and 30 h after GnRH injection. However, all cows in the Saline group ovulated later than 36 h post-injection, with an average time of 52.7 ± 8.6 h. There was no difference in preovulatory follicle diameter between the two groups (16.8 ± 0.5 and 17.3 ± 0.5 mm for GnRH and saline groups, respectively). Although ovulation rate was not correlated with treatment, the rate within 48 h of GnRH injection (93.3%) tended to be higher compared with that in the Saline group (60.0%). Thus, GnRH administration increased ovulation rate following complete luteolysis induced by two low doses of PGF2α. These results indicate that this simple protocol for dairy cows is an effective alternative to timed artificial insemination programs in the field.

Effect of dietary supplementation of omega-3 polyunsaturated fatty acid (PUFA) rich fish oil on reproductive performance of the goat (Capra hircus)

Dietary supplementation of n-3 PUFA decreases the luteolytic PGF2α and improves the pregnancy rate in the dairy cow. However, its effect in the goat is not known. Accordingly, we studied the effect of supplementation of n-3 PUFA rich Fish oil (FO) on different reproductive events in the goat. Cycling goats (n = 30) were divided into two equal groups and fed an isocaloric and isonitrogenous diet supplemented with either FO (TRT; n = 15) or palm oil (PO) (CON; n = 15) @ 0.6 mL/kg body weight for 72 days during the breeding season. Estrus synchronization was done on day 25 and 36 of supplementation using two PG regimen and the goats in estrus were bred. Mean interval from PGF2α administration to the onset of estrus was 12 h longer (P < 0.05) in the TRT group than that of CON. The number of preovulatory follicles (POF) and ovulation rate was significantly higher in FO supplemented goats (P < 0.05) by 39.64 and 41.35%, respectively. Though the corpus luteum diameter was significantly higher (P < 0.05) on day 5, 8 and 11 post-breeding in the TRT group, mean serum progesterone (P4) did not differ significantly (P > 0.05). Mean concentration of serum estradiol (E2) was significantly (P < 0.01) lower in the FO supplemented group during day 0–60 post-breeding which could be due to significantly low serum cholesterol (P < 0.01). Though the serum concentration of PGF2α metabolite (PGFM) and PGE2 metabolite (PGEM) in the pregnant goats was significantly (P < 0.05) lower in the TRT group on day 16 and 17 post-breeding, the ratio of PGEM to PGFM remained unaffected suggesting a favourable effect of FO supplementation on the early pregnancy. The number of embryos, twinning rate and kidding rate were high in FO supplemented group though it was non-significant. However, gestation length, birth weight of kids and neonatal behaviour were comparable between the groups (P > 0.05). In conclusion, supplementation of n-3 PUFA rich FO significantly increased the number of POF and ovulation rate with numerical increase in the kidding rate. Further, it decreased the serum E2 and PGFM during the critical window of pregnancy recognition in the doe.

Postpartum Uterine Infections in Cows: Diagnosis and Treatment - An Overview

Postpartum uterine infections result from uterine contamination with pathogens during parturition. Most of the pathogens are environmental contaminants that are gradually eliminated during the first 6 weeks postpartum. Vaginoscopy is considered to be more accurate than rectal palpation for diagnostic purpose. Transrectal ultrasonography is helpful for the diagnosis of clinical endometrits and pyometra. Subclinical endometritis (SCE) can be detected after three weeks postpartum with the help of endometrial cytology. Administration of PGF2α or intrauterine infusion of cephapirin is the treatment of choice for chronic endometritis but in case of SCE, results are inconsistent. Immunomodulators, ozone pearls or foam have also been used for treatment of postpartum uterine infections. Economic losses associated with uterine infections in dairy cattle are due to cost of diagnosis and treatment of the infection, associated milk reduction and reduced fertility.

The effect of presynchronization with prostaglandin F2α and gonadotropin-releasing hormone simultaneously, 7 d before Ovsynch, compared with Presynch-10/Ovsynch on luteal function and first-service pregnancies per artificial insemination

Pregnancy per artificial insemination (P/AI) following Ovsynch is optimized when cows ovulate to the first GnRH of Ovsynch. Fertility programs are designed to presynchronize cows to d 6 or 7 of the estrous cycle to increase the chances of ovulation of a first-wave dominant follicle to the first GnRH of Ovsynch. The hypothesis of this experiment was that simplification of a presynchronization program through the combination of PGF2α and GnRH on the same day, 7 d before Ovsynch, would allow for similar P/AI compared with Presynch-10. Lactating dairy cows (n = 432) 41 to 47 d in milk (DIM) were randomly assigned to 2 treatments within parities for first service. Control cows received Presynch-10/Ovsynch consisting of the following: PGF2α-14 d-PGF2α-10 d-GnRH-7 d-PGF2α-56 h-GnRH-16 h-AI. Treated cows received PGF2α and GnRH-7 d-GnRH-7 d-PGF2α-56 h-GnRH-16 h-AI. All cows received a supplemental injection of PGF2α 24 h after the PGF2α of Ovsynch to enhance complete luteolysis. All cows received timed AI between 75 and 81 DIM. Blood was collected to assess circulating concentrations of progesterone (P4), and the number and size of corpora lutea (CL) were recorded using ultrasonography on day of PGF2α of Ovsynch. The administration of PGF2α simultaneously with GnRH and 7 d before Ovsynch (PG+G) had similar P/AI at 28 (46 vs. 48%), 35 (43 vs. 43%), 49 (39 vs. 39%), and 77 d post-AI (38 vs. 39%) compared with Presynch-10. No differences were observed in P/AI in primiparous versus multiparous cows at 28 (52 vs. 45%), 35 (48 vs. 41%), 49 (45 vs. 37%), and 77 d post-AI (43 vs. 36%). No difference existed between treatments in percentage of cows with functional CL at PGF2α of Ovsynch, total luteal area (mm2), or serum concentrations of P4 at time of PGF2α of Ovsynch, regardless of parity. Number of CL had a tendency to be greater for multiparous PG+G vs. Presynch-10 cows (2.34 ± 0.09 vs. 2.15 ± 0.08) but not in primiparous cows (1.95 ± 0.10 vs. 1.98 ± 0.11). In summary, administering both PGF2α and GnRH on the same day, 7 d before the start of Ovsynch, appears to be a simple and effective alternative to Presynch-10 Ovsynch.

Excitotoxicity-induced prostaglandin D2 production induces sustained microglial activation and delayed neuronal death

Excitotoxicity is the pivotal mechanism of neuronal death. Prostaglandins (PGs) produced during excitotoxicity play important roles in neurodegenerative conditions. Previously, we demonstrated that initial burst productions of PGD2, PGE2, and PGF2α are produced by cyclooxygenase-2 (COX-2) in the hippocampus following a single systemic kainic acid (KA) administration. In addition, we showed that blocking of all PG productions ameliorated hippocampal delayed neuronal death at 30 days after KA administration. To investigate the role of individual PGs in the delayed neuronal death, we performed intracerebroventricular injection of PGD2, PGE2, or PGF2α in rats whose hippocampal PG productions were entirely blocked by pretreatment of NS398, a COX-2 selective inhibitor. Administration of PGD2 and PGF2α had a latent contribution to the delayed neuronal death, sustained over 30 days after a single KA treatment. Furthermore, PGD2 enhanced microglial activation, which may be involved in the delayed neuronal death in the hippocampus. These findings suggest that excitotoxic delayed neuronal death is mediated through microglia activated by PGD2.

Effect of two low doses of prostaglandin F2α on luteolysis in dairy cows

In this preliminary study, we determined the effect of a modified method involving the administration of two low doses of prostaglandin F2α (PGF2α) at an interval of 24 h on luteolysis in dairy cows, and compared it with the standard single-dose method. Twenty-six cows were assigned to three groups treated with two low doses (TLD group, n = 10), one standard dose (SD group, n = 10), and one low dose (OLD group, n = 6) on day 9 to 10 of the oestrous cycle (day 0 = the day of PGF2α administration). Their serum progesterone (P4) levels and corpus luteum (CL) sizes were measured daily from day 0 to 4 to assess CL regression. The results indicated that the proportion of complete luteolysis, indicating a P4 value ≤ 1 ng/mL on day 3, was higher in the TLD group (100.0%) than in the SD (60.0%) and OLD (66.7%) groups. Ultrasonically detected changes in the CL area correlated with the shifts in the P4 values in both the TLD and the SD groups. The remaining CL area was significantly smaller in the TLD group (17.8% ± 3.3%) than in the SD or OLD group on day 4. Thus, we concluded that the proportion of luteolysis in cows was increased with two low doses of PGF2α as compared to a single PGF2α dose, indicating the necessity of the second dose of PGF2α. However, further studies with larger sample sizes in the field are required.

The Effect of PGF2α, GnRH, E2 or Antibiotics on the Intrauterine Environment and Reproduction in Holstein Dairy Cows with Retained Placentas

PGF2α, GnRH, estradiol (E2), or antibiotics were given to dairy cows with retained placenta after parturition to establish the most suitable treatment to prevent the development of endometritis. One hundred and seventy five parous Holstein cows with retained placenta were allocated to into six treatment groups, and groups were given PGF2α, GnRH, E2, or antibiotics at 30 or 45 days after parturition. The intrauterine perfusion fluid was collected at 60 days after parturition, and a bacteriological and cytological examination was conducted. Reproductive performance was also investigated. The detection rate for Trueperella pyogenes in the intrauterine perfusion fluid in each group ranged from 0% to 16%, and T. pyogenes was not isolated in cows that were given PGF2α or E2. The percentage of neutrophils observed in the intrauterine perfusion fluid ranged from 37.8 ± 5.3 to 56.3 ± 4.7, and it was lowest in cows given PGF2α and highest in cows given GnRH. The mean number of days from parturition to initial insemination, the mean number of days from parturition to conception and the mean number of artificial inseminations required for conception ranged from 85.9 ± 5.5 to 102.7 ± 8.0, 103.8 ± 9.0 to 162.3 ± 18.6 and 1.5 ± 0.2 to 2.6 ± 0.3, respectively. All three parameters were best in cows that were given a combination of PGF2α and E2. The results suggest that administration of PGF2α or E2, or ideally both, might be a suitable treatment for cows with retained placenta. However, treatment with GnRH might delay the cleansing of the uterus.

Dose and Frequency of PGF2α Administration to Lactating Dairy Cows Exposed to Presynchronization and Either Five- or Seven-day Ovsynch Protocols: Ovulation, Luteolysis, and Pregnancy Rates

Dose and Frequency of PGF2α Administration to Lactating Dairy Cows Exposed to Presynchronization and Either Five- or Seven-day Ovsynch Protocols: Ovulation, Luteolysis, and Pregnancy Rates

Onset of luteolytic action of exogenous prostaglandinF-2α during estrous cycle in goats

The objectives of these two experiments were to determine the day of onset of luteolysis after exogenous PGF-2α administration during the estrous cycle and the fertility of this synchronized estrus in goats. In the first experiment, during the breeding season, 48 Nubian does were estrous synchronized, using intravaginal sponges impregnated with a progestin, and estrus was detected by vasectomized bucks. The does were divided at random into three groups of 16 does each to be treated at days 2, 3, and 4 of the estrous cycle (estrus = day 0). Then, at each day of injection, the does were again randomly divided to receive a single dose of natural prostaglandin F-2α im (PGF-2α; 5 mg/doe; treatment [TRE] group) or sterile saline solution (control [CON] group; 1 mL/doe). Finally, the following groups were originated: TRE-2, CON-2, TRE-3, CON-3, TRE-4, and CON-4. The overall estrus response after treatment with PGF-2α (TRE group, 70.8%) was higher than saline (CON group, 12.5%, P ≤ 0.001). Estrus response for TRE-2, CON-2, TRE-3, CON-3, TRE-4, and CON-4 was 25% (2 of 8), 12.5% (1 of 8), 87.5% (7 of 8), 12.5% (1 of 8), 100% (8 of 8), and 0% (0 of 8) for the same groups, respectively. Estrus response was different between day 2 and days 3 and 4 (P ≤ 0.04) and not between day 3 and day 4 (P ≥ 0.05). In the second experiment, 15 multiparous Boer does were estrous synchronized with control internal drug release (CIDR, 300 mg progesterone = P4) and PGF-2α and randomly divided to receive one single dose of PGF-2α im at days 2, 3 or 4, after synchronized estrus (n = 5 at each day). The does were detected twice a day for estrus, and blood was collected daily for P4 determination for 11 days after the synchronized estrus. Each doe in estrus was bred by hand mating to a proven male. All the does with a functional corpus/corpora luteum/lutea (CL; ≥1.0 ng/mL of P4) responded to PGF-2α with a drop in P4 levels that either lasted only 24 h for the does that did not show estrus (0.27 ± 0.10 ng/mL; n = 4) or persisted longer in all the does that showed estrus (0.22 ± 0.18 ng/mL; n = 10; P = 0.47). Estrus response for days 2, 3, and 4 was 20% (1 of 5), 80% (4 of 5), and 100% (5 of 5), respectively (P = 0.05). The conception rate was 100%, 100%, and 80% for the same days of administration, respectively (P = 0.64). It was concluded that luteolytic action of PGF-2α begins at day 3 of the estrous cycle by inducing an ovulatory and fertile estrus in goats.

The effects of preovulatory administration of oral letrozole on ovulatory follicle and the subsequent corpus luteum in mares

Progesterone acts as an important factor in maintenance of pregnancy and development of equine embryo. Treatment with letrozole, a nonsteroidal inhibitor of aromatase enzyme regulating the synthesis of estrogens, during the preovulatory period has been reported to result in larger corpus lutea (CLs) with greater progesterone production in human and bovine. The present study was conducted to evaluate the effect of preovulatory administration of letrozole on the size of CL and progesterone concentration. In the present study, mares (n = 7) received PGF2α (250 μg) 14 days after the observed ovulation and were subjected to daily ultrasonography to evaluate the development of the largest follicle and the resultant CL for two consecutive estrous cycles. In addition, progesterone concentration was measured over the course of luteal phases. During the first cycles, as control cycles, mares received no treatment. During the second cycles, mares received letrozole (0.5 mg/kg) orally beginning from PGF2α administration for 3 days. Letrozole reduced the diameter of ovulatory follicle (P < 0.05) and advanced the time of ovulation (P < 0.05). There was also a tendency for formation of smaller CLs following letrozole administration (P = 0.065). Moreover, concentration of progesterone during midluteal phase was lower following letrozole treatment (P < 0.05). In conclusion, the present study showed that letrozole treatment during the preovulatory period could result in premature ovulation and impair the function of subsequent CL.

Fertility of Angus cross beef heifers after GnRH treatment on day 23 and timing of insemination in 14-day CIDR protocol.

This study compared artificial insemination pregnancy rate (AI-PR) between 14-day CIDR-GnRH-PGF2α-GnRH and CIDR-PGF2α-GnRH synchronization protocol with two fixed AI times (56 or 72hr after PGF2α). On day 0, heifers (n=1311) from nine locations assigned body condition score (BCS: 1, emaciated; 9, obese), reproductive tract score (RTS: 1, immature, acyclic; 5, mature, cyclic) and temperament score (0, calm; and 1, excited) and fitted with a controlled internal drug release (CIDR, 1.38g of progesterone) insert for 14days. Within herd, heifers were randomly assigned either to no-GnRH group (n=635) or to GnRH group (n=676), and heifers in GnRH group received 100μg of GnRH (gonadorelin hydrochloride, IM) on day 23. All heifers received 25mg of PGF2α (dinoprost, IM) on day 30 and oestrous detection aids at the same time. Heifers were observed for oestrus thrice daily until AI. Within GnRH groups, heifers were randomly assigned to either AI-56 or AI-72 groups. Heifers in AI-56 group (n=667) were inseminated at 56hr (day 32 PM), and heifers in AI-72 group (n=644) were inseminated at 72hr (day 33 AM) after PGF2α administration. All heifers were given 100μg of GnRH concurrently at the time AI. Controlling for BCS (p<.05), RTS (p<.05), oestrous expression (p<.001), temperament (p<.001) and GnRH treatment by time of insemination (p<.001), the AI-PR differed between GnRH treatment [GnRH (Yes - 60.9% (412/676) vs. No - 55.1% (350/635); p<.05)] and insemination time [AI-56 - 54.6% (364/667) vs. AI-72 - 61.8% (398/644); (p<.01)] groups. The GnRH treatment by AI time interaction influenced AI-PR (GnRH56 - 61.0% (208/341); GnRH72 - 60.9% (204/335); No-GnRH56 - 47.9% (156/326); No-GnRH72 - 62.8% (194/309); p<.001). In conclusion, 14-day CIDR synchronization protocol for FTAI required inclusion of GnRH on day 23 if inseminations were to be performed at 56hr after PGF2α in order to achieve greater AI-PR.

Effects of calcium salts of fatty acids rich in palmitic and oleic fatty acids on reproduction and serum biochemistry in Barki ewes

The effect of a flushing diet supplemented with calcium salts of fatty acids (CSFA) high in palmitic (37%) and oleic (33.6%) fatty acids on reproductive performance was studied using 30 Barki ewes with a mean weight of 40.0±0.2kg (mean±SD). The control group (n=15) received the basic diet of 1kg/h/d concentrate plus Egyptian clover (Trifolium alexandrinum) hay ad lib and the CSFA group received the basic diet plus 50g/h/d CFSA. The diets were offered for 60 days, prior to (30 d) and subsequent (30 d) to mating. Estrus was synchronized using a single injection of PGF2α prior to the introduction of rams. CSFA-fed ewes had non-significantly different twinning (20.0 vs. 7.1%), prolificacy (1.2±0.1 vs. 1.0±0.1) and female: male lamb sex ratio (72.2 vs. 50.0%) compared to controls; also, pregnancy, embryo survival and lambing rates were not affected by diet. Feeding CSFA resulted in a higher (P=0.06) total number of follicles and number of large follicles; however, the number of small follicles, and diameters of small and large follicles were not significantly different. Serum concentrations of estrogen at estrus were higher (P=0.06) 3days after PGF2α administration in CSFA (52.3±4.2pg/ml) compared to for control (41.6±3.8pg/ml) ewes. There were no significant differences in total number of corpora lutea (CL) or serum concentrations of progesterone during the luteal phase. Diameters of nascent CL were increased (P<0.05) by CSFA treatment (13.0±0.7mm) compared to control (11.2±0.2mm). Serum concentrations of lipid metabolites (TG, CHOL, HDL and LDL) were significantly (P<0.01) elevated relative to controls in the CSFA treatment. Serum TP, G and liver enzymes (ALT and AST) were not significantly affected by treatment. It was concluded that including CSFA in a flushing diet for Barki ewes resulted in increased serum concentrations of lipid metabolites, and improved twinning and prolificacy rates, and female/male lamb sex ratios.

STUDIES ON THE ANESTRUM IN BUFFALO IN DAKAHLIA PROVINCE

Infertility is the most common problem threatened promotion of livestock in Egypt .this study was performed to get in sight the causes and available attempt for solving a problem of anestrus in buffalo –cows ,under a field condition , through the applications of some available hormonal medicaments. On the other hand, to achieve an economic benefit particularly to the small farmer at Dakahlia province . The work was conducted on 80 mature female buffalo –cows of 4-8 year of age and kept under village system in Dakahlia province and suffering from inactive ovaries (40 animals) or palpable corpora leutea{CL} (40 animals) according gynecological examination . all experimental animals showed anestrous for more than 6 months post partum and gynecological examination not revealed any pathological abnormalities in genital tract. Each group was divided into 4 subgroup that incloud 10 animals . sub group (I):- receiving prostaglandin (PGF2α) only ,sub group (II) :- receiving PGF2α plus estradiol , Subgroup (III) :- receiving PGF2α and synthetic gonadotrophin –releasing factor (Gn-RH) ans sub group (IV) receiving Gn-RH only . blood samples were collected from Jugular vein immediately before treatment and just at the appearance of heat .serum was separated and subjected to biochemical and hormonal assay. The results revealed that ,significant decrease in serum progesterone level of animals with inactive ovaries and treated with PGF2α alone. while , progesterone level significantly decreased in animals with palpable CL and treated with PGF2α in combination with estradiol . serum estrogen levels showed significant decrease only incase of animals treated only with PGF2α . Serum calcium levels showed significant decreases in inactive ovaries F.E.Wehaish.et.al., 96 animals and treated with PGF2α in combination with Gn-RH . in-organic phosphorous levels significantly decrease in both groups treated either with PGF2α alone or in combination with Gn-RH . On the other hand , serum magnesium show significant decrease as the result of treating animals of inactive ovaries by PGF2α alone while ,significant increases were found in animals with palpable CL treating with PGF2α with estradiol . We concluded that , administration of PGF2α in combination with estradiol is the beast treatment used in buffalo –cows with palpable CL however, PGF2α alone showed high efficiency in treatment animals suffering from inactive ovaries.

Effects of fixed time AI and AI at detected estrus on conception rate in smallholder zebu and crossbred heifers and cows subjected to double PGF2α administration.

The study was conducted to evaluate estrus response, time to the onset of estrus, and conception rate at fixed time AI and AI at detected estrus in local and crossbred heifers and cows subjected to double administration of PGF2α. One hundred twenty local (heifers, n = 27; cows, n = 33) and crossbreds (heifers, n = 21; cows, n = 39) were used for the study. About 63 and 85.7% of the local and crossbred heifers, respectively, exhibited estrus. Similarly, all crossbred cows and 90.9% of local cows showed estrus. Most heifers came to estrus between 48 and 72h while cows exhibited behavioral signs of estrus between 72 and 96h. AI at detected estrus resulted in higher conception rate than fixed time AI. Pregnancy per artificial insemination was higher in AI at detected estrus than fixed time AI. Accurate estrus detection followed by insemination are crucial factors in maximizing pregnancy, and this study has demonstrated that conception rate in smallholder heifers and cows should be inseminated following estrus detection to maximize the conception rate of the animals.

Follicle Diameter and Systemic Hormone Interrelationships during Induction of Follicle Collapse with Intrafollicular Prostaglandin E2 and F2α in Mares.

The objectives were to determine: (i) whether intrafollicular administration of PGE2 and PGF2α to mares would hasten follicle collapse and (ii) the differences in reproductive hormone characteristics in mares with spontaneous and prostaglandin-induced follicle collapses. Six mares were followed for two oestrous cycles each: when the mares reached a follicle diameter of 30-35 mm and showed mild-to-moderate endometrial oedema, mares were administered a single 0.5 ml dose containing 500 μg PGE2 and 125 μg PGF2α (treatment cycle) or a placebo (0.5 ml of water for injection; control cycle) into the preovulatory follicle (Hour 0). Blood samples were collected, and serial ultrasound examinations were performed until follicle collapse. Treated mares showed follicle collapse significantly earlier (20.0 ± 5.9 h) than the control mares (72.0 ± 10.7 h). The LH, progesterone, total oestrogens and oestradiol concentrations did not differ between groups; however, the progesterone concentration increased more between 48 and 72 h after follicle injection in the treatment compared to the control cycles (P < 0.05). In conclusion, intrafollicular treatment with PGE2 and PGF2α hastened follicle collapse in mares without the simultaneous use of an inductor of ovulation; despite the early induction of follicle collapse, the profiles of LH and oestradiol were not altered. This study provides information on the role of prostaglandins (PGs) in the process of follicle wall rupture and collapse and suggests that this may happen even before the beginning of the sharp rise in circulating LH at the final stage of the ovulatory surge.

The 9-day CIDR-PG protocol: Incorporation of PGF2α pretreatment into a long-term progestin-based estrus synchronization protocol for postpartum beef cows

A pilot experiment was designed to test the hypothesis that administration of PGF2α before progestin treatment would allow for a reduced duration of progestin treatment in a long-term progestin-based estrus synchronization protocol. A modified presynchronization treatment was compared with a standard long-term controlled internal drug release (CIDR) treatment, and treatments were compared on the basis of ovarian follicular dynamics, estrous response rate, synchrony of estrus expression, and pregnancy rates resulting from timed artificial insemination (TAI) in postpartum beef cows. Estrous was synchronized for 85 cows, with cows assigned to one of two treatments based on age, days postpartum, and body condition score. Cows assigned to the 14-day CIDR-PG protocol received a CIDR insert (1.38 g progesterone) on Day 0, CIDR removal on Day 14, and administration of PGF2α (25 mg im) on Day 30. Cows assigned to the 9-day CIDR-PG protocol received PGF2α concurrent with CIDR insertion on Day 5, PGF2α concurrent with CIDR removal on Day 14, and administration of PGF2α on Day 30. In both treatments, split-time AI was performed based on estrous response. At 72 hours after PGF2α (Day 33), cows having expressed estrus received TAI; cows that failed to express estrus by 72 hours received TAI 24 hours later (96 hours after PGF2α on Day 34), with GnRH (100 μg im) administered to nonestrous cows. Estrus-detection transmitters were used from CIDR removal until AI to determine onset time of estrus expression both after CIDR removal and after PGF2α. Ovarian ultrasonography was performed at CIDR removal on Day 14, PGF2α on Day 30, and AI on Days 33 or 34. At CIDR removal on Day 14, diameter of the largest follicle present on the ovary was similar between treatments. The proportion of cows expressing estrus after CIDR removal tended to be higher (P = 0.09) among cows assigned to the 9-day CIDR-PG treatment (93%; 40 of 43) than among cows assigned to the 14-day CIDR-PG treatment (81%; 34 of 42). After PGF2α, a significantly higher proportion (P = 0.02) of cows expressed estrus after synchronization with the 9-day CIDR-PG treatment (91%; 39 of 43) than the 14-day CIDR-PG treatment (69%; 29 of 42). Consequently, pregnancy rate to TAI tended to be increased (P = 0.09) among the 9-day CIDR-PG treatment (76.7%; 33 of 43) compared with the 14-day CIDR-PG treatment (59.5%; 25 of 42). In summary, a long-term CIDR-based estrous synchronization protocol for postpartum beef cows was enhanced through administration of PGF2α at CIDR insertion and CIDR removal.

Dietary n-3 Polyunsaturated Fatty Acid Affects the Onset of Prostaglandin F2α Induced Oestrus in the Goat (Capra hircus)

The objective of the present study was to examine the effect of dietary n-3 PUFA supplementation on oestrus response in the goat following synchronization with prostaglandin analogue. Parous cycling goats (n=17/group) were fed a concentrate diet supplemented with either fish oil (FO) or palm oil (PO). The FO provided n-3 EPA and DHA @ 156 mg kg−1 body weight while PO was given @ 0.6 ml kg−1 body weight to make the diet isocaloric. Oestrus was synchronized using two dose of prostaglandin F2α (PGF2α) at 11 days apart, with first PG on day 25 of oil supplementation. Goats were observed for oestrus twice a day using a vasectomized teaser buck following second injection of PGF2α. The number and diameter of preovulatory follicle (POF) on the day of oestrus was studied using transrectal ultrasonography. The mean interval from PGF2α administration to the onset of oestrus was significantly (χ2df1=7.003, P=0.008) longer in FO than PO supplemented goats (48.71±3.78 vs 37.41±1.75 h). The proportion of goats showed oestrus within 48 h was 94.11% in the PO group (16/17), while it was 58.82% in the FO group (10/17). However, the oestrus duration was not affected by the FO supplementation. The number of POF was higher in the FO group than the PO (2.23±0.14 vs. 1.82±0.15; P=0.054); however the diameter of POF did not differ among the group (6.90±0.10 vs. 6.77±0.14; P>0.05). In conclusion, the supplementation of goats with n-3 PUFA rich FO delayed the onset of PGF2α induced oestrus and increased the POF number on the day of oestrus.