Serum P4 Concentrations Research Articles

Exogenous progesterone-dependent modulation in the follicular dynamics of Bos indicus cattle undergoing repeated ovum pick-up sessions.

The objective of the present study was to evaluate the role of serum progesterone (P4) in follicular dynamics, oocytes' recovery and quality and their in vitro developmental competence during consecutive ovum pick-up (OPU) sessions in Bos indicus dairy cows. Wave-synchronized Sahiwal cattle (n=20) were randomly divided into treatment (n=10) and control (n=10) groups. CIDR was used as a source of external progesterone in the treatment group. Four consecutive OPU sessions at 96-hr intervals were conducted and repeated ultrasonography at 12-hr intervals was done to monitor follicular dynamics. The viable oocytes were processed for IVC following IVM and IVF until day 7. The serum P4 concentrations in the P4 and control groups were recorded as 2.31±0.059 versus.0.32±0.065ng/ml, respectively (p<.05). In the treatment group, the total number of recorded follicles was higher (p<.05; 12.05±0.37 versus. 10.87±0.40), whilst the growth rate (mm/day) of follicles was lower (p>.05). Per session recovered oocytes (5.31±0.19 versus. 3.58±0.21; p<.0001) and recovery rate (54.23 versus. 42.53%; p<.05) were also higher in the treatment group compared to control. Similarly, the viable oocytes (4.54±0.187 versus. 3.06±0.199) and the number of grade I and II oocytes per session (3.37±0.196 versus. 2.06±0.21) were higher (p<.05) in the treatment group compared with the control group. However, the nuclear maturation, cleavage, and blastocyst rate did not differ (p>.05) between the groups. Taken together, during OPU sessions, serum P4 improves oocytes' recovery and quality, whilst does not affect the in vitro developmental competence of recovered oocytes.

PSXII-22 Relationship between beef cow fertility and maternal immunity

Abstract Immunity plays important role in reproduction. There is evidence that maternal immunity changes from a type 1 to a type 2-biased during pregnancy and lack of such a shift may contribute to unsuccessful pregnancy in animals. The objective of the study was to examine the relationship between relative balance between type 1 and type 2 and fertility in suckled beef cows by characterizing relative quantity ratio of IgG 1 and 2 subclasses (IgG1/IgG2). Angus-Hereford cows (n = 394) were synchronized (d0) with a 5-d CIDR protocol. Estrous behavior was monitored using estrus detection aids and visual observation from d5 until AI (d8). On d8 all cows were inseminated at a fixed time and blood samples were collected form to be examined for type1/type/2 ratio and progesterone (P4). A new rapid blood test (D2Dx) was used to assess the type 1/type 2 immunity balance by measuring the relative quantity ratio of IgG1 and IgG2. Pregnancy was determined by ultrasound 48 to 63 days after AI. Overall pregnancy per AI was 51%. Mean relative quantity of IgG1/IgG2 was different (P &amp;lt; 0.05) between non-pregnant and pregnant cows. There was negative relationship between relative IgG/IgG2 ratio and probability of pregnancy to AI (P &amp;lt; 0.05). As IgG1/IgG2 ratio increased, probability of P/AI decreased. Mean relative IgG1/IgG2 ratio was lesser (P &amp;lt; 0.05) in cows detected in estrus vs non-estural cows. There was no correlation between serum P4 concentrations and IgG1/IgG2 ratio. The results indicate that blood IgG1/IgG2 at the time AI has a potential to be used as a marker for pregnancy prediction in beef cows.

Comparative analysis of the hormone production and gene expression profiles in ovine uterus tissue during oestrus cycle synchronized using medroxyprogesterone acetate plus eCG and prostaglandin analogue

The combination of medroxyprogesterone acetate (MPA) and gonadotropin chorionic (eCG) has been widely used to synchronize oestrus cycle in sheep, but their effects on the gene expression in uterine tissue are yet to be elucidated. To evaluate the effect of MPA + eCG or prostaglandin analogue (PA) treatments on the rate of oestrus cycle synchronization, as well as further hormone production and gene expression profiles in uterine tissue, 14 Santa Inês ewes were randomly selected. The MPA + eCG group (n=7) received intravaginal insertion of MPA-impregnated sponges for 14 days and was administered 350 IU eCG on the day of sponge withdrawal. The PA group (n=7) was administered two doses of 100 μg of PA separated by 12 days. The ewes were assessed for the rate of oestrus cycle synchronization and the serum concentrations of progesterone (P4) and estradiol (E2). Additionally, the expression of estrogen receptor (ERα), progesterone receptor (P4R), and immunolocalization of interferon receptor (IFNAR1) in the uterine tissue samples collected 15th day post-mating were examined. The rate of oestrus cycle synchronization was 100% (n=7/7) and 57.14% (n=4/7) in the MPA + eCG and PA groups, respectively. Moreover, the MPA + eCG group exhibited higher serum concentration of P4 than the PA group (p &lt; 0.05). However, the E2 serum concentration did not differ between the two groups (p &gt; 0.05). The relative expression of P4R and ERα mRNA analyzed using real-time PCR and immunodetection of IFNAR1 were similar between the two groups tested (p &gt; 0.05). Conclusively, MPA + eCG treatment improved the rate of oestrus cycle synchronization and endogenous P4 production; however, it did not affect the expression of sex steroid receptors and IFNAR1 in uterine ovine tissue.

Pregnancy and parturition in dromedary camels II. Incidence, timing and factors affecting early pregnancy loss (EPL) and the outcome of twin pregnancies

In this paper, we described the incidence of early pregnancy loss (EPL) both after natural mating and embryo transfer, evaluated risk factors, and summarized the outcome of twin pregnancies throughout gestation in dromedaries under reproductive care. Data were collected over seven breeding seasons at the world's largest camel dairy farm (study 1). In addition, we determined the timing of EPL and monitored serum progesterone (P4) concentration between Days 13–70 of gestation during one breeding season (study 2). In the first study, out of 2970 pregnancies, 507 cases (17.1%) of EPL were diagnosed with transrectal ultrasonography. The rate of EPL after natural mating and embryo transfer was 16.1% (n = 422 out of 2616) and 24.0% (n = 85 out of 354), respectively. Twin pregnancies were detected in 215 cases (7.2% of all gestations), and 57 of those (26.5%) underwent complete EPL. Almost half of the early losses (n = 243; 47.9%) occurred before 30 d of gestation. Another 43.2% (n = 219) of EPL was diagnosed during the next month, and 8.9% (n = 45) occurred after 60 d of gestation. Multivariable mixed effects logistic regression models revealed that the breeding season (year) and twin pregnancy were the most important exposure variables affecting the rate of EPL (P < 0.001). The effect of some male camels was also demonstrated while other factors, such as type of breeding, age category, month of mating, breed/ecotype and reproductive history did not prove to have a significant influence. In the second study, the overall rate of EPL was 24.5% (n = 34 of 139). There was no difference in the incidence of EPL between ET recipient (24.2%, n = 23 of 95) and mated (25%, n = 11 of 44) camels. Weekly rate of EPL ranged from 0.9% to 4.8% with a decreasing tendency, and approx. 41% of the animals (n = 14 of 34) had some ultrasonographic signs of impending EPL 1 week before the final diagnosis. Mean serum P4 concentration in camels with subsequent EPL was 5.3 ± 0.1 ng/ml compared to 5.6 ± 0.04 ng/ml in normal pregnant dromedaries. Day of gestation and future EPL influenced serum P4 levels (P < 0.001) with an interaction between the two fixed factors (P < 0.05). At the time of the final diagnosis of EPL, mean serum P4 concentration was 2.8 ± 0.44 ng/ml. Although twinning had an unfavorable prognosis with a total pregnancy loss of 36.7%, it was not entirely detrimental for the final outcome of gestation as two-thirds of twin pregnancies (n = 136 out of 212) resulted in the birth of a live calf.

Effect of PGF2α treatments during early corpus luteum development on circulating progesterone concentrations and ovulation in breeding-age Holstein heifers

The objective of this study was to test the effect of low circulating concentrations of progesterone (P4) on pre-ovulatory follicle development in heifers as part of an overarching objective to develop a model to understand this phenomenon in dairy cattle without the confounding factors of lactation. Holstein heifers between 12 and 13 mo of age were pre-synchronized to ensure all heifers were on d 6 of the estrous cycle at the start of the Ovsynch program. Only heifers with CL regression and ovulation to the following pre-treatment strategy were used in the study: 0.5 mg cloprostenol (PGF2α), 2 d later, 0.1 mg GnRH, 6 d later, GnRH (G1; 1st GnRH of Ovsynch). Heifers (n = 159) responding to pre-treatment were randomly assigned to 4 groups and completed the Ovsynch program: high P4 control (HPC), low P4 control (LPC; PGF2α 24 h after G1), PG2 (PGF2α 24 and 48 h after G1) and PG3 (PGF2α 24, 48, and 96 h after G1). Only heifers that had ovulation to G1 remained in the study. Blood samples were collected in all heifers on d 7 (n = 157) and in a subset of heifers on d 1, 2, 3, 4 (n = 82) after G1 to measure serum P4. Pre-ovulatory follicle size at G1 (13.0 ± 0.1 mm; P = 0.53) and mean serum P4 24 h after G1 (d 1; 3.62 ± 0.11 ng/mL; P = 0.46) did not differ among treatments. HPC heifers had greater (P < 0.001) mean serum P4 compared to LPC, PG2 and PG3 on d 2, 3, 4, and 7. On d 2, 3 and 4, mean serum P4 of LPC, PG2 and PG3 heifers did not differ (P > 0.10). On d 7, LPC heifers had greater (P < 0.001) serum P4 compared to PG2 and PG3 heifers. Mean ± SEM serum P4 on d 7 after G1 was 8.43 ± 0.39, 2.55 ± 0.36, 1.58 ± 0.20, and 1.21 ± 0.15 ng/mL for HPC, LPC, PG2, and PG3, respectively. Percentage of heifers with P4 < 0.50 ng/mL on d 7 was greater (P < 0.05) for LPC, PG2 and PG3 (27, 32 and 26%, respectively) compared to HPC (0%). A greater (P < 0.05) proportion of heifers ovulated before G2 in the LPC, PG2 and PG3 than in the HPC. For heifers that ovulated after G2, low serum concentrations of P4 in LPC, PG2 and PG3 induced double ovulations in 6/97 heifers after the final GnRH of Ovsynch compared to 0/33 in HPC. In summary, PGF2α treatments during early CL development reduced circulating P4 concentrations 7 d after G1 compared with both HPC and LPC. However, it did not effectively control CL and follicle function to be utilized as a model to test high vs. low serum P4 on fertility parameters in Holstein heifers.

Association between the Area of the Highest Flank Temperature and Concentrations of Reproductive Hormones during Pregnancy in Polish Konik Horses-A Preliminary Study.

Simple SummaryThermographic imaging is a potentially useful tool in pregnancy detection in equids, especially native or wildlife breeds. In late gestation, the differences in temperature of the flank area between pregnant and non-pregnant mares were suspected to be caused by hormonal effects on regional blood flow. This preliminary study aimed to assess changes in thermal features of the abdomen lateral surface and concentrations of reproductive hormones in Polish native pregnant mares. The study was carried out on pregnant and non-pregnant Polish native Konik Polski mares, and both the hormonal profile and the thermal pattern of mares’ abdomens were examined monthly. The features from thermal images in rainbow HC and gray palette were extracted to determine relations with a hormonal profile dependent across the months of pregnancy. The new feature of a thermal image in the gray palette, the area with the highest temperatures (Area of Tmax), was found to be significantly related to progesterone and relaxin blood concentration. The standard features of the thermal image did not show any similar associations over consecutive months of pregnancy. In this preliminary study, a new approach to thermographic imaging analysis based on the Area of Tmax calculation was proposed. However, further research is needed to better understand the relation between the Area of Tmax and concentrations of reproductive hormones, especially including an experiment with at least daily blood sampling and the hair coat lengths examination.Determination of the pregnancy status is one of the most important factors for effective pregnancy management. Knowledge of the stage of pregnancy is important to interpret many of the reproductive hormones’ concentrations, including progesterone (P4), estrone sulfate (E1S), 17-ß estradiol (E2), and relaxin (REL). However, it is limited in wildlife or captive equids that cannot be handled. Reproductive hormones affect regional blood flow, the proliferation of tissues, and local metabolism intensity. Therefore, this preliminary study aimed to assess changes in thermal features of the abdomen lateral surface and concentrations of reproductive hormones in Polish native pregnant mares. The study was carried out on 14 non-pregnant and 26 pregnant Polish Konik mares during eleven months of pregnancy. Infrared thermography was conducted to image the lateral surface of mares’ abdomen (Px1) and flank area (Px2); P4, E1S, E2, and REL concentrations in serum were also determined. The evidence of the association between the area with the highest temperatures (Area of Tmax) and serum concentrations of P4 (the slope = 1.373; p = 0.9245) and REL (the slope = 1.342; p = 0.4324) were noted dependent across months of pregnancy. Measures of superficial body temperatures were found to change monthly, similarly to ambient temperatures, with no evidence of coincidence with changes in reproductive hormone concentrations. Individual thermal characteristics of the lateral surface of the abdomen differed between pregnant and non-pregnant mares in other periods. Differences in maximal and average temperature and Area of Tmax were observed from the sixth month of pregnancy, and those in minimal temperature were observed from the eighth month.

Influence of Backfat Thickness and the Interval from Altrenogest Withdrawal to Estrus on Reproductive Performance of Gilts.

Simple SummaryAltrenogest, also known as allyl trenbolone, is a steroidal progestin that is widely used in veterinary medicine to synchronize estrus in gilts. To achieve the target number of services per week, enough weaned sows and gilts are needed each week for breeding. A problem with progestogen-synchronized replacement gilts is the variation of the interval between last feeding of altrenogest and onset of estrus. In the present study, we found that gilt backfat thickness had a strong positive correlation with the interval between last feeding of altrenogest and onset of estrus. This result may come from a larger reservoir of altrenogest in adipose tissue in fatter gilts.Estrus synchronization of gilts can be achieved by feeding the orally active progestogen altrenogest (AT) to cycling gilts at 20 mg/day for 14 to 18 days with gilts usually returning to estrus 4 to 8 days after the last feeding. In practice, gilts failing to exhibit estrus by 6 days after AT withdrawal may compromise weekly breeding targets. The cause of prolonged intervals to estrus are unknown but may involve prolonged suppression due to the release of progesterone (P4), and by extension AT, from adipose tissues. The present study examined relationships between gilt P2 backfat depth (<13.5 mm, 14–16.5 mm, >17 mm groups), the AT withdrawal to estrus interval, and subsequent reproductive performance in gilts. We noted longer intervals to estrus in gilts with greater P2 backfat depths (p < 0.0001), and higher serum P4 concentrations on the last day of AT feeding and at estrus detection (p < 0.05). Total born litter sizes were unaffected by backfat depth, but pigs born alive progressively decreased with increasing backfat depth with the fattest gilts producing the fewest liveborn pigs (p < 0.05). Taken together, these data suggest that adipose tissues may provide a reservoir of steroid, with its release from fatter gilts having potential negative effects on their subsequent reproductive performance.

Evaluation of surface plasmon field-enhanced fluorescence spectroscopy for rapid measurement of progesterone concentration in bitches.

To compare progesterone (P4) concentrations measured with surface plasmon field-enhanced fluorescence spectroscopy (SPFS) and chemiluminescence immunoassay (CLIA) in serum and plasma samples of client-owned bitches of various ages and breeds and to determine reference ranges for P4 concentrations at various stages of the estrous cycle. 102 serum samples and 104 plasma samples. In experiment 1, 1 aliquot each of serum and plasma was analyzed for P4 concentration by use of SPFS incorporated in a veterinary-specific point-of-care immunologic analyzer and CLIA. In experiment 2, serum collected from bitches in various stages of the estrous cycle was analyzed for P4 concentration by use of SPFS to establish reference ranges for each stage. In experiment 1, P4 concentrations measured by SPFS and CLIA were highly correlated (serum, r = 0.966; plasma, r = 0.968). In experiment 2, ranges of serum basal (proestrous) P4 concentrations (n = 114) and P4 concentrations at the estimated time of ovulation (76), during pregnancy or diestrus (107), and during the prepartum period (50) measured with SPFS were 0.42 to 1.46 ng/mL, 3.69 to 7.85 ng/mL, 11.73 to 28.24 ng/mL, and 1.54 to 3.22 ng/mL, respectively. Because serum and plasma P4 concentrations measured with SPFS were highly correlated with those measured with CLIA and ranges of serum P4 concentrations measured with SPFS for each of phase of the estrous cycle were well-defined for the large sample size, veterinarians may be able to accurately use this veterinary-specific point-of-care immunologic analyzer with SPFS methodology to determine P4 concentrations of bitches in their daily practice.

Pharmacological approaches to induce follicular growth and ovulation for fixed-time artificial insemination treatment regimens in ewes

In Experiment I, during the non-breeding season, after intravaginal devices containing progesterone (P4) were withdrawn (n = 28), estrous rates were greater with treatment with 400 IU eCG (P < 0.05) than with FSH (10 and 15 mg) and no treatment. During the breeding season (n = 147), estrous and pregnancy rates after fixed-time artificial inseminations (FTAI) were similar among groups: 300 IU eCG; 10 mg FSH; and control (P > 0.05). In Experiment II (non-breeding season), ewes of one group were treated with 300 IU eCG (n = 8) and of two groups were treated with 10 mg FSH. In one FSH group, 250 μg estradiol benzoate (EB) were administered after 24 h (n = 9); in the other, 4 μg GnRH were administered after 36 h (n = 10). Serum P4 concentrations were greater in eCG-treated ewes (P < 0.05). Estrous rates were similar for the eCG- and FSH plus EB-treated ewes (P > 0.05). In Experiment III (breeding season), the treatments were: 300 IU eCG; 250 μg estradiol cypionate; 250 μg EB; or control (n = 22). Follicular growth was greater for eCG-treated ewes within 0−24 h and for control ewes within 48−72 h (P = 0.001). Although estrous and ovulation rates did not differ (P > 0.05), all eCG-treated ewes had ovulations. During the non-breeding season, FSH treatment promoted follicular growth but did not induce ovulations. For FTAI regimens, eCG was more effective than FSH plus GnRH and estradiol esters in inducing estrus and ovulation.

Human chorionic gonadotropin dose response for induction of ovulation 7 days after a synchronized ovulation in lactating Holstein cows

Our objective was to assess the effect of treatment with GnRH or 4 increasing doses of human chorionic gonadotropin (hCG) on the ovulatory response of a first-wave dominant follicle and subsequent plasma progesterone (P4) concentrations. Lactating Holstein cows were blocked by parity (primiparous vs. multiparous) and randomly assigned to receive no treatment (control, CON; n = 147), 100 μg of GnRH (n = 144), or 1,000 (n = 138), 2,000 (n = 144), 2,500 (n = 142), or 3,300 (n = 139) IU of hCG 7 d after the last GnRH treatment (G2) of a Double-Ovsynch (DO) or Resynch protocol. Blood samples were collected and ovaries were evaluated with transrectal ultrasonography immediately before treatment and 7 d later to assess serum P4 concentrations and ovulatory response to treatment. Data were analyzed using the MIXED and GLIMMIX procedures of SAS (SAS Institute Inc., Cary, NC). Overall, ovulatory response differed and was 4.8, 79.0, 77.4, 88.9, 92.9, and 95.6% for CON, GnRH, 1,000-, 2,000-, 2,500-, and 3,300-IU hCG treatments, respectively. The increase in plasma P4 concentrations from 7 to 14 d after G2 differed among treatments and was 3.5, 5.9, 5.7, 6.6, 7.0, and 6.5 ng/mL for CON, GnRH, 1,000-, 2,000-, 2,500-, and 3,300-IU hCG treatments, respectively. In conclusion, lactating Holstein cows treated 7 d after G2 with 100 μg of GnRH or 1,000 IU of hCG had similar ovulatory responses (~78%), whereas cows treated with 2,000, 2,500, or 3,300 IU of hCG had increased ovulatory responses (~92%). Ovulatory response of cows treated with 2,000 or 2,500 IU of hCG did not differ, whereas the ovulatory response after 3,300 IU was greater than that after 2,000 IU of hCG. Plasma P4 concentrations and luteal volume 7 d after treatment were increased compared with those of untreated control cows.

PSVIII-16 Interferon-TAU in the pathogenesis and prevention of intrauterine growth restriction and embryonic death in dairy cows

Abstract The aim of the research was to assess the state of the hormonal and cytokine blood profiles of Holstein dairy cows during the early period of gestation with physiological formation of the embryo, its intrauterine growth restriction and death, clarify the pathogenetic mechanisms of these embryopathologies development and identify the efficacy of their prevention using recombinant bovine INFT. The dynamics of serum concentration of P4, cortisol (F) and cytokines: INFT, interleukin IL-2, tumor necrosis factor (TNFα), interferon-γ (INF-γ) at the physiological formation of the embryo (n = 9), its growth restriction (n = 9) and death (n = 8) were studied. The blood samples were obtained on the day of artificial insemination, during early blastogenesis (days 8–9), implantation of the embryo (days 15–16), the formation of primary genital organs (days 32–33), and at the end of the embryonic period of development (days 60–65). In cows with intrauterine growth restriction and embryonic death, serum concentration of P4, compared with the cows demonstrating their physiological formation, was lower by 14.0–30.1%, F - by 11.2–35.5%, INFT - by 21.0–37.7% when the content of IL-2 was exceeded by 46.5–310.5%, TNFα - by 11.7–36.2%, INF-γ - by 58.0–296.0%. A statistically significant positive correlative relationship between the content of INFT, P4, F and a negative one with the indices of the concentration of proinflammatory cytokines was found. Violation of the hormonal-cytokine balance in the organisms of fertilized animals is a universal pathogenetic mechanism for the development of early embryopathies. Injections of recombinant bovine INFT to inseminated cows during the pre- and implantation periods increased the level of progesterone production and reduced the synthesis of proinflammatory cytokines. The efficacy of insemination of cows increased by 1.96 times, the manifestation of fetal/embryonic intrauterine growth restriction syndrome decreased by 2.35 times in comparison with the control animals.

Follicular and luteal morphofunctionality of dairy cows supplemented with calcium salts of fatty acids in AIFT programs

We aimed to define the effect of strategic supplementation with calcium salts of fatty acids on the morphofunctionality of ovarian structures in crossbred dairy cows submitted to a hormonal protocol for artificial insemination at a fixed time (AIFT) A total of 20 lactating crossbred females (Bos taurus x Bos taurus indicus) were randomly divided into two groups, the control group (CON), which received concentrate with no added fat in the diet, and the treatment group (TRAT), which received concentrate with salts of fatty acid calcium (Megalac-E, Church and Dwight Co. Inc., Trenton, NJ, marketed in Brazil by Elanco-Eli Lilly and Company, Indianapolis, IN, USA). The diets were provided for 30 days. The animals started consuming the supplement 20 days before the beginning of the follicular wave and ovulation synchronization protocol (Day-20). Follicular development was monitored by mode B ultrasound and power-doppler assessments every 12 h between day D8 and the time of ovulation. By measuring the follicular diameter (DFOL), the area of the follicular wall (AFOL) and the vascularization area of the follicle wall (VFOL) were able to be determined. On days 7 and 16 after ovulation, US mode B and doppler were performed in order to analyze the corpus luteum diameter (DCL), area of the corpus luteum (ACL), and the vascularization area of the corpus luteum (VCL). In addition, blood samples were collected to measure the serum concentration of P4 using chemiluminescence methodology. There was no effect of supplementation on milk production results (p = 0.15), body weight (p = 0.57), ECC (p = 0.78), albumin (p = 0.83), and the lipid profile (CT [p = 0.36], HDL [p = 0.11], LDL [p = 0.55], VLDL [p = 0.15] and TRIG [p = 0.15]). The supplementation of SCAG, 30 days before IATF, under the conditions of this experiment had no significant influence on follicular and luteal morphofunctionality. However, suspension of supplementation caused a deficit in the luteal blood flow.

Effects of equine chorionic gonadotropin administered via the Baihui acupoint on follicular ovarian dynamics and the luteal function of cattle during an ovulation synchronization treatment regimen for fixed-time artificial insemination

Objectives were to evaluate effects of a smaller than typically used dose of equine chorionic gonadotropin (eCG) during a fixed-time artificial insemination (FTAI) treatment regimen. Transrectal ultrasonic (US) examinations were conducted on dairy cows on Day 0 (D0) and the treatment regimen was initiated with administrations of an intravaginal progesterone (P4) implant, estradiol benzoate (im), and prostaglandin F2α (PGF2α; im). On D8, the P4 implant was removed and PGF2α and estradiol cypionate were administered to all animals. Subsequently, cows were randomly assigned to three groups and eCG was administered to Groups 1, 2, and 3 in doses of 300 (im); 100 (im); and 100 (Baihui acupoint) IUs, respectively. The B-mode and power-flow US cineloops were performed to assess follicular dynamics and evaluate various morphological and vascular characteristics of the corpus luteum. Blood samples were collected to quantify serum P4 concentrations. There were no differences between the ovulation synchronization treatment regimens for all follicular dynamic variables tested; however, cows in Group 3 differed from Group 2 having a larger follicle diameter (FD) on D10 (P = 0.06) and larger preovulatory FD (P = 0.09), as well as a blood perfusion area of the dominant follicle wall on D8 (P = 0.07). There were no differences in responses to the ovulation synchronization treatment regimens for the luteal variables evaluated subsequent to ovulation. In conclusion, the Baihui acupoint was effective as an alternative route for eCG dose reduction when FTAI treatment regimens were imposed without detrimentally affecting values for reproductive variables.

The effect of prostaglandin and gonadotrophins (GnRH and hCG) injection combined with the ram effect on progesterone concentrations and reproductive performance of Karakul ewes during the non-breeding season.

The effect of prostaglandin and gonadotrophins (GnRH and hCG) combined with the ram effect on the progesterone (P4) concentrations and reproductive performance of Karakul ewes was investigated during non‐breeding season. Ewes (n = 93) received a male effect and were divided into two treatment groups including GnRH ‐ hCG (hCG, n = 32), GnRH ‐ GnRH (GnRH, n = 30) and a control (n = 31) group. This study was carried out from April (hormonal injection) to October (lambing). The first doses of GnRH (4.2 μg, Buserelin) were injected at the beginning of the study in treatment groups. These ewes were treated with hCG (250 IU) or the second GnRH dose five days later. All animals received two injections (ten days apart) of 150 μg PGF2α five days after the hCG or the second GnRH injection. Mating was initiated two days after the second prostaglandin injection and lasted for 34 days. Blood samples were collected by jugular venipuncture on days −10, −5, 0 (first PGF2α injection), 17 and 30 during the study. Pregnancy diagnosis was performed through transabdominal ultrasonography on day 40 after the removing of ram. Conception rate was 93.8, 90 and 87.1% in the hCG, GnRH and control groups, respectively. Lambing rate tended to increase in the hCG group compared with the control group (87.1 versus 58.1%; p < .1). There was no significant difference in P4 concentrations among studied groups in identical sampling times (p > .05). In conclusion, the administration of prostaglandin and hCG in combination with the ram effect tended to decrease lambing period. In other words this protocol tended to increase lambing rate at the first cycle. Treatment with hCG or GnRH did not increase serum P4 concentrations of treated Karakul ewes during the non‐breeding season.

Serum progesterone concentration, volume, and apoptosis of corpora lutea in early, middle and late diestrus in the bitch

The aim was to study number, volume, apoptosis of corpora lutea (CL), and serum P4 concentrations in early, middle, and late diestrus of dogs. Thirty-six bitches were ovari-hysterectomized (OVX): Early Diestrus (Group [G]1; OVX 20 days after end of estrus [DEH]); Mid-diestrus (GII; OVX between 21 and 40 days after DEH), and Late-diestrus (GIII; OVX between 41 and 60 days after DEH). Before OVX a blood sample was collected to quantify P4. After OVX, the number of CL (NCL) was recorded, CL measured using both ultrasonography (US) and caliper (CAL), and the volume (mm3) was calculated. Based on abundances of caspase-3, apoptotic luteal cells were detected. Bitches in early-diestrus had greater P4 concentrations than bitches in mid- and late-diestrus (23.52 ± 3.78 and 10.86 ± 3.88 ng/mL; P < 0.05). The NCL, cumulative USCLV, and CALCLV were similar among diestrus stages (P > 0.30). Bitches with CL (≥5) had twice the serum P4 concentrations as bitches with CL1−2 and CL3−4 (22.71 ± 3.70 and 10.97 ± 4.06 ng/mL; P < 0.05). There were correlations between P4 concentrations with USCLV, CALCLV, and NCL (r = 0.64, r = 0.67, r = 0.44; P < 0.0001). When serum P4 concentrations were adjusted for stages of diestrus, however, there were only correlations during early diestrus. The percentage of apoptotic cells was greater in GIII compared with GI and GII (13.75 ± 2.26 % compared with 4.5 ± 0.68 % and 4.6 ± 1.5 %, respectively; P < 0.05). As days of diestrus increased, number of apoptotic cells increased, and serum P4 concentrations decreased.

Exogenous progestogens differentially alter gene expression of immature cumulus–oocyte complexes in sheep

This study evaluated the role of progesterone (P4) and medroxyprogesterone acetate (MAP) on the molecular status of immature cumulus–oocyte complexes (COCs) and the implications for oocyte quality in sheep. The number of viable COCs per ewe and the rate of COCs screened for developmental competence by brilliant cresyl blue positive (BCB+) were similar (P > 0.05), respectively, across treatments (P4: 7.7 ± 0.7 and 4.7 ± 1.2; MAP: 5.7 ± 1.0 and 3.5 ± 2.3; and control: 5.7 ± 1.1 and 3.6 ± 2.4). The COCs' gene expression was altered by exogenous progestogens compared with the control group: markers of steroidogenic pathway (FSH receptor [FSHr], LH receptor [LHr], and estradiol receptor α) and of quality (zygote arrest 1, growth differentiation factor 9, and B-cell lymphoma 2) were in abundance in P4 (P < 0.05). In addition, reelin protein (RELN) was downregulated, and Bcl-2 was upregulated in MAP (P < 0.05). In the P4 vs MAP comparison, FSHr, LHr, and RELN genes were upregulated (P < 0.05) in the P4 group. In conclusion, P4 and MAP promoted dissimilar effects on transcriptome profiling of immature BCB-selected COCs, possibly due to the differences in the chemical structure of progestogens and concentrations of serum P4. Exogenous P4 impacted positively on the profile of genes related to oocyte quality.

Effect of two chamber type with different depths on stallion sperm kinematic parameters

Thirteen dromedaries were used to study the relationship between the size of the dominant follicle, vaginal electrical resistance (VER), sexual receptivity, and serum concentrations of oestradiol-17β (E2) and progesterone (P4) throughout the follicular phase. On a daily basis, the animals experienced teasing with a vasectomised camel, trans-rectal ultrasound examination of the ovaries, and measurement of VER and blood collection for serum E2 and P4. Results revealed no significant differences between the mean VER in the animals that had a follicle of 5–10 mm (group I, n = 11), 11–15 mm (group II, n = 12) and 16–20 mm (group III, n = 13). The VER did not correlate with the follicular size. The E2 concentrations in the animals in groups II (60.14 pg/ml) and III (66.52 pg/ml) were significantly (P < 0.05) higher than those of animals in group I (48.31 pg/ml). E2 was positively correlated (r = 0.50; P < 0.05) with the overall size of the follicles. The P4 concentration was significantly (P < 0.05) lower in the animals of group II than in those in groups I and III. Serum P4 concentrations were inversely correlated (r = −0.40; P < 0.05) with the overall size of the follicles. Complete sexual receptivity was reported in 63.64%, 16.67% and 76.92% of the animals in groups I, II and III, respectively. In group III, significant (P < 0.05) complete sexual receptivity was confirmed. However, 23.08% of the animals were incompletely receptive. In conclusion, impedometric characteristics of the vaginal mucosa were not a reliable method for predicting the dominant follicular size during the follicular phase in dromedary camels.

Subdose of human chorionic gonadotropin applied at the Hou Hai acupoint on follicular dynamics and luteal development in donkeys.

The objective of this study was to evaluate the effects of an hCG subdose applied at the Hou Hai acupoint as an ovulation inducer in donkeys. Eleven donkeys were distributed in randomized blocks in T1 = application of 1,500 IU of hCG intravenous (IV); T2 = 450 IU of hCG applied at the false acupoint (IV), and T3 = 450 IU of hCG applied at the Hou Hai acupoint. There was no difference (P > 0.05) between the treatments regarding the mean diameter of the pre-ovulatory follicle (34.5 ± 1.3 mm), the ovulation rate (96.97%), the interval between induction and ovulation (58.07 ± 16.82 h), the mean diameter of the CL (D0 = 23.0 ± 0.6; D2 = 27.7 ± 1.9 and D8 = 28.2 ± 0.8mm), and serum P4 concentrations (10.50 ± 2.99 ng.mL-1). The application of 450 IU of hCG at the Hou Hai acupoint increased ovulation rate (72.73%) more than 48 h after induction (P = 0.03) and a larger diameter of the CL on D4 (30.7 ± 5.1 mm) (P = 0.04). The vascularization area of the CL on D8, obtained by minimum number of colored pixel (NCP), was greater (P < 0.05) in the donkeys that received 1,500 IU of IV hCG (T1, 41.91 ± 1.17), and we found a positive correlation (P < 0.05) between mean NCP and P4 concentration in the donkeys that received 450 IU of hCG IV at the false acupoint (T2) or at the Hou Hai acupoint (T3). The application of 450 IU of hCG by IV route at the false acupoint or the Hou Hai acupoint was sufficient to induce ovulation in donkeys, demonstrating that the average dosage commonly used for this species is too high.

Evaluation of anti-Mullerian hormone, antral follicle count and progesterone concentration during estrous cycle in Murrah buffaloes

An experiment was conducted to study the anti-Mullerian hormone (AMH) concentration, antral follicle count (AFC) and progesterone (P4) concentration during estrous cycle in Murrah buffaloes. Seven animals of 5–10 years were selected for the study. All the animals were synchronized as per the ovsync protocol and the pair of ovary of each animal was scanned by ultrasonography on 0, 3rd, 7th, 11th, 14th, 17th and 21st day of estrous cycle. Blood was collected on the same day to evaluate serum AMH and P4 concentration. The nonsignificant difference was observed in antral follicle count of 3–5 mm, 5–8 mm and total follicles count (&gt; 3 mm), whereas, significantly lower mean values of &gt;8 mm of antral follicles were recorded on the day of estrus (0.14 ±0.14) as compared to 3rd, 7th, 11th, 14th, 17th and 21st day of estrous cycle. The significant individual variation was recorded in average mean of 3 - 5 mm and total antral follicle count (&gt;3 mm). However, the difference for 5 - 8 mm and &gt;8 mm was nonsignificant. The positive correlation of low and high antral follicle count was observed in the present study. Two animals of low antral follicle count remained non pregnant and two animals showed 3 follicular waves during estrous cycle. The nonsignificant difference was recorded in AMH concentration during estrous cycle, whereas, individual variation in AMH concentration differ significantly. The progesterone concentration showed significant increase and decrease in values according to the stages of estrous cycle.

Factors influencing English Bulldog bitch fertility after surgical uterine deposition of fresh semen

The aim of this study was to evaluate the effect of body weight, oxytocin deposition in the uterus at artificial insemination (AI), vaginal cytology, serum progesterone (P4) concentration at AI, semen volume and total sperm cells per AI on whelping rate and litter size of English Bulldogs bitches following intrauterine surgical semen deposition. Seventy-eight English Bulldog bitches were artificially inseminated via semen infusion (number of sperm cells inseminated 300–2500 × 106) at the uterine body with fresh semen without extender and under general anesthesia. Whelping rate was greater (P < 0.05) in bitches with >23 kg than bitches with <23 kg (83.9 vs 63.8%). Whelping rate was greater (P < 0.01) in bitches with >75% vaginal cornified epithelium at AI (85.1%) than animals with <75% cornified epithelium (51.6%). Whelping rates were influenced (P < 0.01) by the semen volume at AI (54.3% vs 86.1% for bitches receiving <4 mL or >4 mL of semen). Litter size was larger (P < 0.05) in bitches >23 kg than lighter animals (3.72 ± 1.79 and 2.30 ± 1.46 pups per litter, respectively). Litter size was not influenced by sperm concentration, semen volume, vaginal cytology, serum P4 concentration and infusion of oxytocin in the uterus at AI (P > 0.1). The results of this study indicate that increasing body weight of English Bulldog bitches is related to higher whelping rates and larger litter size. Also, >75% of superficial cornified vaginal cells (squamous) at AI and >4 mL semen volume maximize whelping rates in this breed of dogs.