PGF2α Administration Research Articles

Effects of exogenous progesterone on the ovine serum progesterone profile during the non-breeding season

Exogenous progesterone (PRG) sources are used to induce ovine estrus during the non-breeding season. Intramuscular injection (IM) of PRG is an uncommon route for this purpose. This study investigated serum progesterone (P4) levels after IM administration of 50 mg of two different PRG products. Ten ewes were selected and received two consecutive PGF2α injections at 24-h intervals. Serum samples were collected (Time 0), followed by the injection of single doses of Fertigest® or Vetagesterone®. Serum P4 levels were assayed at times (T) 0, 30 min, 3,6,12,24,48,72,96, and 120 h after injection. A large variation in the serum P4 levels at T0 was detected. The serum P4 level at T0 was 4.3 ng/mL, which is considerable for anestrus ewes, following PGF2α administration. The mean time to reach maximum serum P4 concentration was 5.8 h, with a mean concentration of 22.5 ng/mL. Serum P4 levels returned to basal values (T0) after 48 h. An increased P4 production rate (PR) was detected following PRG administration, which continued for 24 h. A single injection of PRG reduced the variety of serum P4 levels from 24 h onward. The two different PRG generated different serum P4 concentrations. This study indicates an unusual change in serum P4 levels in anestrus ewes following PGF2α administration. 48 h after 50 mg PRG injection, the plasma levels of P4 reached basal levels in anestrus ewes.

Impact of antral follicle count on follicular-luteal characteristics, superovulatory response, and embryo quality in Sahiwal cows.

The study aimed to evaluate the effect of antral follicle count (AFC) on follicular and luteal development during the estrous cycle and superovulatory period, as well as on superovulatory response and in vivo embryo quality within the MOET program. A total of 48 estrus-induced (500 μg PGF2α, Single dose, IM) Sahiwal cows (Bos indicus) with a BCS between 3.5 and 4.0 were selected for the study. On the day of wave emergence, the animals were divided into two groups based on the AFC, i.e., low AFC (≤18) and high AFC (>18). Both the groups were monitored daily using B-mode ultrasonography (USG) for one cycle, and the superovulation protocol was initiated on the 9th day of the subsequent estrous cycle. A total of 240 μg of FSH in eight divided doses were given in a tapering sequence for 4 days and simultaneous administration of 500 μg PGF2α, along with the fifth dose of FSH. Donors were inseminated at superovulatory estrus using double straws of high-quality frozen semen thrice at 12-h intervals, and non-surgical flushing was performed on day 7 of the superovulatory estrus followed by embryo searching and evaluation under a stereo zoom microscope. Ovulatory waves of the high-AFC Sahiwal cows have significantly (p ≤ 0.05) larger sizes of preovulatory follicles (POF) (12.06 ± 0.19 mm vs 11.56 ± 0.16 mm) and corpus luteum (CL) (19.57 ± 0.28 mm vs 18.26 ± 0.35 mm), as compared to low AFC. The ovarian size was significantly (p < 0.0001) larger in cows with high AFC during the superovulatory protocol. The number of large, medium, and small follicles was significantly (p < 0.0001) high on the day of superovulatory estrus (SOE), PGF2α administration, and initiation of superovulatory protocol, respectively, in high AFC. Donors with high AFC had a notably greater (p < 0.0001) count of CL and embryos retrieved per flushing, including excellent and fair-quality embryos. A strong association (p < 0.0001) between high AFC and ovarian size (r = 0.9136), superovulatory response (r = 0.9350), and embryo quality (x2 = 8.788; p = 0.032) and number (r = 0.9858) were also recorded. Based on these results, AFC is considered a dependable indicator for forecasting reproductive capacity. Bos indicus donors with an average AFC of 30 or higher are recommended.

Effect of intrafollicular administration of PGE2 or PGF2α in early estrus on ovulation, hemorrhagic anovulatory follicles formation, progesterone secretion and pregnancy outcome in the mare

This experiment was performed to evaluate whether intrafollicular treatment of PGE2 or PGF2α administered in early estrus would induce normal ovulation, progesterone production (Experiment 1) and pregnancy (Experiment 2). In Experiment 1, mares in estrus after 2 days of endometrial edema were injected in all largest dominant follicles (28–35 mm in diameter) with 0.5 mL of sterile water containing 500 μg PGE2 (n = 6), 125 μg PGF2α (n = 6) or placebo (n = 7) (Hour 0). Ultrasound examinations were performed daily, until ovulation or anovulation was detected, and daily blood samples were taken for 8 days. In Experiment 2, mares with a dominant follicle ≥35 mm after at least three days of slight-to-moderate endometrial edema, were injected with 500 μg PGE2 diluted in 0.5 mL of sterile water for injection in the follicle (PGE2 group; n = 9 mares and 11 dominant follicles). No puncture was performed in the control group (n = 9 mares and 11 dominant follicles). Mares from both groups were inseminated. In Experiment 1, all mares (6/6) in the PGE2 group ovulated within 24 h of treatment. The mean interval from intrafollicular injection to ovulation was shorter (P < 0.001) in PGE2 mares (24 ± 0 h) than in control mares (77 ± 9 h). Mares from the PGF2α group developed hemorrhagic anovulatory follicles (HAF) more often (7/7) than control mares (2/7); P < 0.05). The progesterone concentration in mares from the PGF2α group was lower (P < 0.004) than control mares in the early post-ovulatory period. The first significant increase in post-ovulatory progesterone concentration occurred earlier (P < 0.05) in mares from the control group than in mares from the PGF2α and PGE2 groups. In Experiment 2, more mares from the control group (7/9, 78 %) became pregnant than from the PGE2 group (2/9, 22 %) (P = 0.015). In conclusion, PGE2 alone induced follicle collapse in all treated mares within 24 h of administrations, while PGF2α blocked ovulation and induced formation of HAFs. However, the post-ovulatory rise in progesterone production was delayed and the fertility reduced in mares with ovulation induced by PGE2 compared to control mares.

Effect of prostaglandin treatment on the estrus behaviour, follicular and luteal morphometry and serum hormone profile in sub-estrus buffaloes during non-breeding season.

Sub-estrus buffaloes do not exhibit estrus signs despite being cyclic contributing to extended service periods and inter-calving intervals causing significant economic loss. The present study described the effect of synthetic prostaglandin (PGF2α) on estrus behaviour, follicular and luteal morphometry, and serum estradiol (E2) and progesterone (P4) profile in sub-estrus buffaloes during the non-breeding season. The incidence of sub-estrus was 38.4% during the non-breeding season. The sub-estrus buffaloes (n = 33) were divided into two groups, viz., Control (n = 16) and PGF2α treatment (Inj. Cloprostenol 500 μg, i.m., n = 17). Estrus induction response was significantly greater in the treatment (100 vs. 18.75%, p < .001), and a relatively greater proportion of animals conceived in the treatment group (29.41 vs. 6.25%, p = .08). The time elapsed to induction of estrus and insemination following treatment was significantly lower in the treatment group than control. A significant increment in the follicle diameter (9.72 ± 0.45 vs. 13.00 ± 0.45 mm, P < .0001) and serum estradiol (E2) concentration (66.01 ± 11.92 vs. 104.9 ± 13.21 pg/mL, p = .003) observed at the post-treatment period in the PGF2α treatment group. At the same time, CL diameter was reduced significantly at a higher regression rate in the PGF2α treated buffaloes than those of control. Of the responded buffaloes, only 30% showed high-intensity estrus attributed to the expulsion of cervico-vaginal mucus (CVM), uterine tonicity, micturition, and mounting response by a teaser bull. From this study, it can be concluded that the administration of PGF2α could induce estrus in the sub-estrus buffaloes during the non-breeding season. Behavioural changes, along with sonographic observation of POF, regressing CL, and serum E2 and P4 concentration would be useful to determine the right time of insemination in sub-estrus buffaloes during non-breeding season.

Effect of exogenous oestrogen treatment frequency on induction of artificial lactation in pseudopregnant sows.

In this study, we examined whether the frequency of exogenous oestrogen treatment affects the induction of artificial lactation and milk production. Furthermore, we analysed changes in milk components obtained from artificially lactating sows. Pseudopregnant induced by treatment with 30 mg of estradiol dipropionate (EDP) on Day 10 (Day 0 = the last day of estrus) were divided into three groups: those administered 5 mg of EDP once on Day 39 (n = 5), twice on Days 32 and 39 (n = 5) and three times on Days 25, 32 and 39 (n = 6). All animals were treated with prostaglandin F2α (PGF2α) on Day 46 for induced lactation. Artificial lactation was induced in 66.7%-80.0% of sows, and the EDP treatment frequency before PGF2α administration had no significant effect on either the induction rate of artificial lactation or the milk yield during the experimental period. The milk composition (levels of crude protein, crude fat, crude ash, lactose and immunoglobulin) did not differ among the groups. In conclusion, the number of EDP treatments prior to PGF2α administration had no effect on either the efficiency of artificial lactation induction or milk production.

Effects of repeated embryo flushing without PGF2α administration on luteal function, percentage of unwanted pregnancy and subsequent fertility in mares.

PGF2α is commonly given at the end of embryo flushing (EF) to shorten the interval to the next oestrus and ovulation. To determine the effect of repeated EF on plasma progesterone concentration, percentage of mares with endometritis, unwanted pregnancy and subsequent fertility in mares flushed without the use of PGF2α. Controlled experiments. Nine mares were inseminated in seven consecutive cycles (n = 63), to either perform an EF (n = 54) 7-9 days after ovulation or left pregnant (n = 9). PGF2α was not used to induce oestrus. Ultrasound examination and blood sampling were performed just before the EF and 72 h later to determine changes in progesterone concentration and signs of endometritis. The overall percentage of positive EF/pregnancy was 55.5% (30/54) and 66.7% (6/9), respectively. The likelihood of pregnancy/positive EF in the first three cycles was 55.5% (15/29). This was not different (p > 0.1) from the fertility of the last four cycles (69.4%, 25/36). In five EF cycles (9.3%), mares had signs of endometritis and early luteolysis (progesterone <2 ng/mL) 72 h after EF. The reduction in progesterone concentration by 72 h after EF was greater (p < 0.05) for Day 9 (-2.3 ± 0.7 ng/mL) than Day 7 (-1.0 ± 0.8 ng/mL) or Day 8 (-1.3 ± 1.1 ng/mL) cycles. The progesterone concentration in non-flushed mares did not vary significantly during the sampled period (Day 7-12). There were 5 cycles in which the donor mare remained pregnant after the EF, although four were from a single mare. The mare population was limited to barren and maiden mares. The cycle order and operator allocation to each EF were not randomised. EF induces a subtle, but significant reduction in progesterone concentrations compared with non-EF cycles. However, the percentage of mares with EF-induced full luteolysis is low (9.3%). The fertility of mares after repeated EF without administration of PGF2α was unaffected; however, there is a considerable risk of unwanted pregnancy (5/27 = 18.5%) in donors from which an embryo was not recovered.

The Effectiveness of Intrauterine Treatment with Momordica charantia L. on Some Hormone Parameters in Repeat Breeder Cattle

Background: Repeated breeding is a substantial problem in dairy cattle affecting reproductive efficiency. The goal of the current study was to see how intrauterine treatment of phytotherapeutic plant extract affected some hormonal indicators and conception rates in dairy cattle with fertility issues. Methods: In the study, 40 repeat breeder (RB) cattle were randomly divided into two groups. Forty ml (0.25 g/mL) Momordica charantia L. (MC) extract was administered intrauterine to cattle in group I (n=20) and 40 ml of pure olive oil was administered intrauterine to cattle in group II (n=20) at a time. The control group, group III (n=20), was composed of healthy heifers. Endometrial smear samples were taken from all RB cattle for cytological examination before the treatment and all were stained with Giemsa. Estradiol (E2), progesterone (P4) and insulin-like growth factor (IGF-1) levels were assessed by collecting blood samples starting from intrauterine treatment on days 0, 7 and 14. After the last blood sample was collected, the estrus cycles of all cattle were synchronized through a double dose of PGF2α administration at 14-day intervals. GnRH was administered with single insemination at the 60th hour following the second PGF2α treatment. Result: Subclinical endometritis was determined in 82.5% (33/40) of RB cattle. Pregnancy rates in group I, group II and group III were determined as 55%, 35% and 35%.respectively.(P greater than 0.05). There was no significant difference in E2 values according to time and between groups. For P4, there were also no significant differences between three time-dependent measurements, but there was a difference in the 7th and 14th days of the groups (P less than 0.01). For IGF-1, significant differences were found between the three time-dependent measurements of the groups (P less than 0.001). In conclusion, it was observed that the MC extract treatment, especially in RB with SCE, can improve the pregnancy rate by positively affecting the increase in IGF-1 which is a key element of the extremely complex endocrine system.

Impact of Time Interval between PGF2α Administration and Semen or Blood Plasma Collection on Spermatozoa Quality, Testosterone Level, cAMP, and Plasma ATP Level in Rats

Impact of Time Interval between PGF2α Administration and Semen or Blood Plasma Collection on Spermatozoa Quality, Testosterone Level, cAMP, and Plasma ATP Level in Rats

The fertility of dairy heifers and cows is not influenced by the follicular wave of the ovulatory follicle.

Two studies were conducted to evaluate the effects of the follicular wave on ovarian function and fertility in dairy heifers and lactating cows. In study 1, the estrous cycle of the selected Holstein heifers was initially synchronized using two intra-muscular prostaglandin F2α (PGF2α) administrations 11 days apart. Heifers in group FFW (n = 14) received an intra-muscular 500 μg PGF2α administration on day 7 after detecting standing estrus, while Heifers in group SFW (n = 14) were administered PGF2α 13 days after detecting standing estrus. The pregnancy rates of FFW (n = 98) and SFW (n = 100) heifers were also determined 35-37 days after artificial insemination (AI). In Study 2, healthy Holstein lactating cows (n = 28) were randomly assigned to either the FFW (n = 14) or SFW (n = 14) groups. The estrous cycles of the cows were presynchronized using two intra-muscular administrations of PGF2α given 14 days apart. Then, the emergences of the follicular waves were induced using an Ovsynch protocol. The pregnancy rate of FFW (n = 99) versus SFW (n = 98) cows was also determined 35-37 days after AI. The ovulatory follicle and corpus luteum (CL) resulting from the ovulatory follicle of FFW were larger than those of the dominant follicle and the CL of SFW in dairy heifers and lactating cows. However, the pregnancy rate did not differ between the FFW and SFW groups in heifers and lactating cows 35-37 days after AI. In conclusion, although the characteristics of the ovulatory follicles in FFW versus SFW animals differed, the follicular wave in dairy heifers or lactating cows did not affect fertility.

Farrowing Induction in Swine with Prostaglandin: Effect on Farrowing Traits and Piglet Performance

The variation of gestation length in sows leads to difficulties performing farrowing supervision in commercial farms. The present study determined the efficacy of prostaglandin F2alpha (PGF2α) administration on induction of farrowing in pig. The sows (n=50) were randomly divided into two groups. In group-1, sows (n=25) were injected with placebo intramuscularly (one mL sterile water) on 113th day of gestation at 8.00 am in the morning. In group-2 (n=25), cloprostenol sodium (250 mcg) was injected intramuscularly on 113th day of gestation at 8.00 am in the morning. The parameters recorded during the experiment were gestation length, farrowing duration, total number of piglets born per litter (NTB), number of piglets born alive per litter (NBA), number of stillborn per litter, mummified foetuses per litter, birth interval (min), number of piglets alive at day 3 of lactation and piglet mortality (%) till day 3 of lactation. Gestation length was significantly (p&lt;0.05) shorter in Group-2 compared to Group-1. Similarly, the interval from PGF2α administration to onset of farrowing was significantly (p&lt;0.05) shorter as compared to natural farrowed sows. Farrowing duration did not differ significantly (p&gt;0.05) between two groups. There was no effect of PGF2α administration on NTB, NBA, stillbirths, mummified fetuses. The numbers of alive piglets at day 3 of lactation were also similar between two groups (p&gt;0.05). The PGF2α administration also resulted in increased proportion of sows that farrowed on day 114 of gestation. In conclusion, PGF2α administration on day 113 of gestation could be an option for controlled farrowing in sow without any adverse effects.

289 Postnatal Obesity Amplifies the Effect of Prenatal Testosterone Excess in Reducing the Progesterone Negative Feedback Sensitivity in First-Generation Ewes

Abstract Polycystic ovary syndrome (PCOS) is the leading cause of anovulatory infertility in women of reproductive age. Women with PCOS exhibit reduced sensitivity of the GnRH neuronal system to the inhibitory effects of both progesterone and estradiol. Additionally, obesity amplifies the severity of the PCOS phenotype. In sheep, testosterone (T) excess during gestational days (GD) 30-90 and 60-90 reduces neuroendocrine sensitivity to the progesterone negative feedback and recapitulates the PCOS phenotype. This study investigated the contribution of postnatal obesity in amplifying or mitigating the effects of mid-gestational T excess in disrupting the responsiveness to progesterone negative feedback in sheep. Suffolk ewes received T propionate (T; 100 mg i.m.) or corn oil (CO; vehicle) twice weekly from GD 60-90 (term = 147 d). At 5 mo of age, F1 T lambs were assigned randomly to either a maintenance (100% of NRC requirements) or overfed diet (130% of NRC requirements) and control lambs were fed the maintenance diet. At 22 mo of age, F1 ewes (n = 8/group) were synchronized with two injections of PGF2α 11 d apart. After the second PGF2α administration, blood samples were collected daily for 14 d and progesterone concentrations were determined via radioimmunoassay. Ewes that were confirmed to be cycling and in the mid-luteal phase based on progesterone concentrations (progesterone ≥ 1 ng/ml on day 10 and ≥ 0.5 ng/ml on days 8-9 and 11-12) were used for LH pulse characterization. On day 10 after PGF2α synchronization (mid-luteal phase), blood samples were collected every 15 min for 6 h to characterize LH pulsatile secretion via radioimmunoassay. Data were analyzed as one-way ANOVA with Tukey's HSD post-hoc analysis. Frequency of LH pulses was greater (P &amp;lt; 0.05) in T maintenance (3.75 ± 0.41 pulses/6h) and T overfed ewes (3.50 ± 0.34 pulses/6h) compared with controls (2.00 ± 0.37 pulses/6 h). Luteinizing hormone pulse amplitude was greater (P &amp;lt; 0.05) in T overfed (2.03 ± 0.15 ng/mL) compared with T maintenance (1.44 ± 0.17 ng/mL), but not to controls (1.74 ± 0.21 ng/mL). Also, average LH concentration was greater (P &amp;lt; 0.05) in T overfed (2.03 ± 0.24 ng/mL), but not T maintenance (1.31 ± 0.35 ng/mL), compared with controls (0.93 ± 0.30 ng/mLl). In conclusion, these findings demonstrate the activational role of postnatal obesity in amplifying prenatal T-induced alterations in tonic LH secretion during progesterone negative feedback. The activational effect of postnatal obesity in increasing LH secretion and consequently thecal androgen production is likely a contributor to the severity of hyperandrogenic status in women with PCOS. Research support: NIH-NICHD (R01HD099096).

PSIV-15 Economic Impact of a 14-D Cidr Pre-Synchronization on Cost Per Pregnancy in Holstein Heifers

Abstract Feed cost is the largest expense in developing dairy heifers with improved reproductive performance there is opportunity to reduce costs through decreasing days on feed to first calving. The objective of this study was to compare the economic impact of a 14-d CIDR pre-synchronization protocol to no pre-synchronization in Holstein heifers during an 84-d breeding period. Heifers were divided in two treatment groups 1) 14-d CIDR pre-synchronization (pre-synch; n = 20) and 2) control (n = 16). Heifers in the pre-synch treatment received a CIDR on d -30 which were removed on d -16. On d 0 (day of breeding eligibility) heifers in both groups were administered PGF2α and an Estrotect patch for estrus detection. On d 0, body weight of the heifers was estimated using a heart girth tape for large breeds. Estrotect patches were assessed once daily in the morning and heifers with ≥ 50% of the patch scratched received AI the same morning with Holstein sexed semen. After AI, heifers received a new Estrotect patch to facilitate return to estrus. Heifers that failed to express behavioral estrus within 14 d after PGF2α administration received another dose of PGF2α every 14 d until the first behavioral estrus was observed. Approximately thirty days after AI, heifers were subjected to ultrasonography of uterine contents for pregnancy diagnosis, and re-confirmed pregnant at ~60 d. Heifers diagnosed open received an injection of PGF2α and a new Estrotect patch. Partial budget analyses utilize these prices: feed cost ($1.75/heifer/day), PGF2α ($3.29/dose), needle and syringes ($0.12/per injection), Estrotect patch ($1.20/unit), AI procedure ($10.00/AI), semen ($35.00/straw), CIDR ($16.60/unit), pregnancy diagnosis ($5.00/heifer), overall labor ($0.41/heifer/day), and extra labor for CIDR group ($1.25/heifer). The partial budget was calculated per heifer and per pregnant heifer by charging pregnant heifers the cost of the remaining open heifers at the end of the 84-d period. There was no difference (P ≥ 0.26) in weight at d 0 (399.9 ± 15.2 vs 398.4 ± 15.8 kg), age at d 0 (371.6 ± 8.7 vs 371.5 ± 8.9 d), days to first AI (6.85 ± 2.28 vs 6.27 ± 2.50 d), days to pregnancy (20.55 ± 7.52 vs 14.09 ± 8.22 d), average number of services (2.10 ± 0.30 vs 2.06 ± 0.34 AI/heifer), average number of services to pregnancy (1.56 ± 0.24 vs 1.50 ± 0.27 AI/heifer), proportion of heifers receiving AI in the first 7 d (85.0 ± 8.0 vs 68.8 ± 11.6 %), proportion of heifers pregnant at first service (50.5 ± 12.5 vs 56.4 ± 13.5 %) and final pregnancy rates (80.0 ± 8.9 vs 75.0 ± 10.8 %) for pre-synch and control, respectively. Average cost per animal ($ 194.50 ± 30.27 vs 170.44 ± 33.85) and average cost per pregnancy ($ 243.12 ± 37.16 vs 206.95 ± 42.91) were not statistically different (P ≥ 0.53) between pre-synch and control, respectively. In summary, the use of a 14-d CIDR pre-synchronization did not have a significant economic impact on the performance of Holstein heifers during an 84-d breeding period.

Amelioration of Seminal Plasma Testosterone Concentration in Gembrong Goats after In Vivo Administration of PGF2α

The semen quality of Gembrong goats is lower than other goats and may be related to the low concentration of testosterone hormone. Implementation of reproductive technology using prostaglandin F2α (PGF2α) hormone is beneficial to increase the testosterone hormone in Gembrong goats. This study aimed to determine the effect of PGF2α injection on increasing testosterone levels in Gembrong goats. Male Gembrong goats (n=4), aged 2.5-4 years with similar body condition scores (BCS=3) were used in this study. Goats were divided into two treatment groups (n=2). Goats in group 1 (G1) were injected intramuscularly with 1 ml PGF2α (75 μg), while those in group 2 (G2) were injected with 1 ml physiological NaCl. Semen collection was carried out 30 minutes after treatment using an artificial vagina. Testosterone levels were measured using the enzyme-linked immunosorbent assay (ELISA). The collected data was tabulated and analyzed descriptively. The results showed that the average testosterone concentration of G1 was higher than G2 with respective concentrations of 6.41 ± 0.70 and 2.81 ± 1.75 ng/ml. It was concluded that administration of PGF2α in vivo could increase testosterone concentration in Gembrong goats.

Effects of prostaglandin F2α treatment at follicular wave emergence on endometrial epidermal growth factor concentration on day 3 of the next estrous cycle and on fertility in dairy cows

Inadequate exposure to estradiol (E2) and progesterone (P4) may be the main causes of altered endometrial epidermal growth factor (EGF) profile, leading to reduced fertility in dairy cows. We hypothesized that PGF2α administration at different timings of the estrous cycle and stages of follicular development could change the profile of steroid hormones between luteolysis and estrus. This results in reduction in the peak concentration of endometrial EGF on day 3 (day 0 = estrus) in the next estrous cycle. In study 1, lactating Holstein cows were treated with PGF2α either on days 12–14 (selection phase group, n = 20) or on days 16–17 (control group, n = 24) of the estrous cycle. Blood samples were obtained before PGF2α treatment, 24 and 48 h after treatment, and on the day of estrus and ovulation for E2 and P4 assays. Endometrial tissues were collected by biopsy on day 3 for EGF assays. The duration from PGF2α treatment to both estrus and ovulation was longer in the selection phase group than in the control group (P < 0.05). The time between estrus and ovulation was longer in the selection phase group (P < 0.05). E2 concentrations were higher in the control group on the day of estrus (P < 0.05). P4 concentrations were not different between the groups. Endometrial EGF concentrations were lower in the selection phase group than in the control group (P < 0.05). In study 2, lactating Holstein cows were treated with PGF2α either on day 12 (selection phase group, n = 76) or day 16 (control group, n = 80). They were subjected to artificial insemination (AI) at estrus, and those that failed to ovulate by 24h after the first AI were subjected to second AI. On day 3, endometrial EGF concentration was determined. At estrus and on days 3 and 7, blood was collected for E2 and P4 assay from 20 randomly selected cows in each group before PGF2α treatment. The cows in the selection phase group exhibited lower EGF concentration, proportion of cows with normal EGF profile, and conception rate than cows in the control group (P < 0.05). On the day of estrus, E2 concentrations tended to be lower in the selection phase group than in the control group (P = 0.08). P4 concentrations were not different between the groups. These findings suggest that low E2 concentrations at estrus and low P4 concentrations for a prolonged period due to premature termination of CL in the absence of a dominant follicle are potential causes of altered endometrial EGF profile in dairy cows.

Impact of Different Therapies on Haemtological Parameters and Therapeutic Outcome in Subclinical Endometritic Buffaloes

The objective of this study was to compare the effect of administration of intrauterine dextrose, s/c levamisol and intrauterine PGF2α on haematological indices and therapeutic response in endometritic buffaloes. Twenty eight repeat breeder buffaloes with subclinical endometritis were randomly assigned into four groups. Seven animals were kept as Control (untreated C), and the rests were assigned to three treatment group, i.e., T1 (Dextrose I/Ut, 50 mL 4 times on the day of estrus), T2 (Levamisol s/c, @ 2.5 mg/kg b.wt. on day 0, 7 and 14 of the cycle), and T3 (PGF2α I/Ut, @ 0.25 mg in 0.5 mL saline twice, on the day of first and next estrus). Following treatment the values of Hb, TEC and PCV elevated significantly and TLC values dropped to normal or near normal in all three treatment groups as compared to control group. Furthermore, the post-treatment neutrophils and lymphocytes counts were elevated significantly in all four groups. However, there was no any definite pattern of eosinophils and basophils. The therapeutic response (clinical recovery) was 14.29, 71.43, 85.71 and 42.86 % in T0, T1, T2 and T3 group, respectively. The corresponding conception rates were 0.00, 60.00, 66.67 and 66.67 %. The results conclude that, Dextrose intrauterine, Levamisol s/c, and PGF2α intrauterine can be used effectively to manage subclinical endometrtitis in buffaloes.

Evaluation of minimally invasive estrus synchronization protocols in brown brocket deer (Subulo gouazoubira)

This study aimed to evaluate minimally invasive protocols for estrus synchronization in the brown brocket deer (Subulo gouazoubira). Females were submitted to Latin square design, in different treatments. All females received 0.25 mg of estradiol benzoate on the first day of treatment, concomitant with one of the following sources of progesterone: (1) DIP: an intravaginal progesterone releasing device for eight days, (2) MGA1x: once a day (in the morning) oral dose of 1 mg melengestrol acetate for eight days, (3) MGA2x: twice a day (morning and afternoon) oral doses of 0.5 mg of MGA for eight days, (4) P4LA: a single i.m. administration of 75 mg of long-acting progesterone (P4LA). Eight days after the beginning of each treatment, females received an i.m. administration of 265 µg of prostaglandin (PGF2α; cloprostenol). Treatment efficacy was evaluated by manifestation of behavioral estrus after treatment and concentration of fecal progesterone metabolites (FPM). The time to onset of estrus in treatment P4LA was significantly longer (180 ± 38.9 h) compared to DIP (63 ± 6.6 h), MGA1x (53 ± 14.4 h) and MGA2x (41 ± 10.1 h) (P = 0.008). According to individual baseline FPM and FPM concentration during the days after estrus, the corpus luteum formation was suggested in all females which responded to the treatments (93.75 %). Low synchrony, longer interval between PGF2α administration and onset of estrus suggest that the P4LA dose (75 mg) is too high and not effective for S. gouazoubira. DIP, MGA 1x and MGA 2x, were effective in estrus synchronization.

Increase of Body Temperature Immediately After Ovulation in Mares.

To successfully inseminate mares, precise detection of ovulation time is crucial, especially when using frozen-thawed semen. Monitoring body temperature, as has been described in women, could be a noninvasive way to detect ovulation. The objective of this study was to investigate the relationship between the time of ovulation and the variation of body temperature in mares based on automatic continuous measurements during estrus. The experimental group included 21mares for 70analyzed estrous cycles. When the mares showed estrous behavior, they were administered intramuscular deslorelin acetate (2.25mg) in the evening. At the same time, monitoring of body temperature using a sensor device fixed at the left lateral thorax was started and continued for over 60hours. In 2-hour intervals, transrectal ultrasonography was performed to detect ovulation. Estimated body temperature in the 6 hours following ovulation detection was on average 0.06°C +/- 0.05°C (mean+/-SD) significantly higher when compared with body temperature at the same time on the preceding day (P=.01). In addition, a significant effect of PGF2α administration for estrus induction on the body temperature was found, being significantly higher until 6hours before ovulation compared to that of uninduced cycles (P=.005). In conclusion, changes in body temperature during estrus in mares were related to ovulation. The increase in body temperature immediately after ovulation might be used in the future to establish automatized and noninvasive systems to detect ovulation. However, the identified temperature rise is relatively small on average and hardly identifiable in the individual mares.

Effect of embryo flushing technique, number of flushing attempts and previous experience of operator on embryo recovery

The aims of this study were 1) to determine the effect of operator experience and embryo flushing technique on embryo recovery (ER) in each flushing attempt; 2) to determine the percentage of unwanted pregnancies and endometritis following embryo uterine lavage without administration of PGF2α. Seven non-lactating mares were inseminated with the same semen in four cycles (n=28 cycles). Embryo flushing was performed 7-9 days after ovulation by two operators of different experiences: experienced (>500 flushes) and beginner (<5), using two different flushing techniques in a crossover design. Mares were flushed three times with Ringer's Lactate (RL) “in-and-out”: 1L during the first two attempts and 0.5L during the third attempt. The remaining 0.5L was used to flush the tubing system. The two flushing techniques were 1) uterine massage (UM): continuous ballottement and massage of the uterus per rectum during RL recovery in each attempt, 2) control: the RL was allowed to flow back without touching the uterus during the first two attempts, and during the third attempt (0.5L) the uterus was manipulated as in UM. In both groups, 20 IU of oxytocin were administered at the second attempt and the RL was allowed to remain in the uterus for 3 minutes before recovery. No PGF2α was administered at the end of the flushing procedure. The overall ER was13/28 (46.4%). Ten embryos (10/13,77%) were recovered in the first filter, and 3 in the third filter. The experienced operator obtained a higher (P<0.05) ER (10/14) than the beginner (3/14). The ER of controls (6/14) was similar (P>0.1) to the UM (7/14). More embryos (7/7, P=0.06) were recovered in the first filter in the UM compared with the control group (3/6). Two mares entered prolonged dioestrus following a positive ER. Two mares with a negative ER (13%, 2/15) were pregnant 14 days after ovulation: both were from the control group and flushed by the beginner. In these mares, horn expansion was incomplete after RL infusion in every attempt. The last 8 embryos recovered in the study were transferred using the Wilsher´s technique immediately after recovery in the same donors, but none became pregnant. The overall mean inter-ovulatory interval was 22.5d (16-29d). Six mares (21.4%) developed free-intrauterine fluid and early luteolysis, of which 4 mares had been transferred with their own embryos. In conclusion, the previous operator´s experience had the greatest effect on overall ER. The uterine massage influenced the flushing attempt´s number in which the embryo was recovered. Oxytocin had no effect on ER. The risk of unwanted pregnancies in donors flushed by a beginner with no PGF2α treatment, was considerable.

Effects of embryo flushing on serum progesterone levels and the inter-ovulatory period in Arabian donor mares

To obtain the maximum number of cycles throughout the breeding season, avoid unwanted pregnancies and possible endometritis, the luteal phase of donor mares is shortened after embryo flushing. This is achieved by treating the donor with prostaglandin F2α (PGF2α) to destroy the corpus luteum and hence shorten the inter-ovulatory interval (IOI). It has been suggested that manipulation of the cervix and/or uterus during embryo flushing may result in release of endogenous of PGF2α and/or oxytocin, resulting in altered luteal function with a consequent decrease in progesterone and shortening of the cycle. Conversely, other authors have proposed no change in or extension of cycle length following embryo flushing. The purpose of this study was to evaluate the effects of embryo flushing with or without administration of PGF2α on serum progesterone levels and inter-ovulatory interval (IOI). Over two breeding seasons, 26 cycles of 6 Arabian donor mares, aged 4-15 years were studied. Inseminated mares were flushed on Day 8 or 9 post ovulation using Ringer's Lactate and a standard closed embryo flushing technique. After flushing the mares were divided into 2 groups; Group 1 (n=9) were treated with dl-Cloprostenol and Group 2 (n=17) were untreated. Blood wascollected on the day of embryo flushing and 48h later and the serum frozen until analysis using a progesterone ELISA kit (DRG Instruments, Marburg, Germany). For statistical analysis, a Shapiro-Wilks normality test was performed before 2-way ANOVA, followed by Tukey's post hoc and unpaired T tests. A significant decrease in plasma progesterone concentrations was observed in Group 1 mares (12.08 ± 3.91 ng/ml at flushing vs 0.7 ± 0.28 ng/ml at 48h, p<0.001) but not in Group 2 (12.62 ± 4.76 ng/ml at flushing vs 10.89 ± 3.57 ng/ml at 48h, p=0.549). The inter-ovulatory interval was shorter in Group 1 compared to Group 2 mares (18.56 ± 1.94 vs. 20.94 ± 1.84 days, respectively; p=0.006). Only 2 cycles had follicles ≥28mm at the time of embryo flushing and PGF2α was not administered in those cycles. Although the IOI was shortened by a mean of 2.38 days in mares given PGF2α, this was less than the 5-6 days which the dioestrous phase of the cycle had been shortened by. Based on the results obtained in this study, manipulation of the reproductive tract during embryo flushing does not result in endogenous release of PGF2α and/or oxytocin that is sufficient to cause luteolysis of the CL or cause a significant decrease in serum progesterone levels in embryo donor mares.

Ovarian and Energy Status in Lame Dairy Cows at Puerperium and Their Responsiveness in Protocols for the Synchronization of Ovulation.

The purpose of this study was to assess the ovarian and energy status of multiparous lame dairy cows at the end of puerperium and investigate their responsiveness to estrous synchronization treatment regimens. Initial lameness scoring was performed at 28 ± 5 and 37 ± 5 d post partum, followed by lesion documentation and treatment. Cows were blocked by lameness severity and were randomly allocated to an estrous synchronization treatment regimen with seven days of progesterone supplementation (group LP, n = 26) or with an administration of PGF2α twice, 14 d apart (group LC, n = 26). Non-lame cows served as controls (group C, n = 27) and the same treatment regimen was imposed as that for group LC. Twelve days after estrous presynchronization, an Ovsynch treatment regimen and timed AI were imposed. Ultrasonography of the ovaries and blood sampling for progesterone were used to assess cyclicity status, whereas β-hydroxybutyrate (BHBA) and non-esterified fatty acids (NEFA) were used to assess energy status. Lame cows were to a greater proportion non-cycling (36.5% vs. 11.1%; p = 0.02), had greater overall NEFA concentrations (0.32 ± 0.02 vs. 0.26 ± 0.02 mEq/L; p = 0.02) and a greater incidence of elevated NEFA concentrations (53.9% vs. 29.6%, p = 0.04) compared to control cows. However, no interaction between energy and lameness status was evident regarding non-cycling cows. The percentage of cows responding to the presynchronization, synchronization and ovulating did not differ between groups LP, LC, and C. The first-service conception rate (FSCR) tended to be greater for group C (37.0%) compared to group LP (16.0%; p = 0.08). Long-term reproductive performance did not differ between lame and control cows, although culling rates did (21.2% vs. 0%, respectivly; p = 0.01). The severity of lameness had an effect on culling rates (30.6% vs. 0% for cows with marked vs. moderate lameness; p = 0.01), whereas the type of lesion largely explained poor reproductive performance (FSCR 13.9% vs. 40.0% for cows with claw horn disruptions vs. infectious lesions; p = 0.04). Conclusively, cows that were lame during puerperium are at a greater risk of not cycling irrespective of energy status. Treatment regimens for the synchronization of ovulation seem to be efficient at resuming ovarian cyclicity. Marked lameness was detrimental to survivability, whereas cows with claw horn lesions had compromised reproductive capacity.