Plasma Progesterone Concentrations Research Articles

Blue LED light treatment of pregnant mares is not detrimental to gonadal development in their offspring

A light program transmitted via blue LED light directed at one eye from individual light masks (Equilume, Kildare, Ireland) to pregnant mares from the middle of December onwards advanced the onset of foaling with birth of mature and healthy foals, but they were slightly smaller than foals from untreated control pregnancies (Lutzer et al., Domestic Anim Endocrinol 2022;78:106675). Differences, however, equilibrated within the first year of life. In this study we followed the hypothesis that light treatment of pregnant mares is without detrimental effects on body size and gonadal development of offspring after puberty. A total of 47 warmblood horses born and raised on the same stud farm to blue LED light-treated (17 males and 9 females) or control mares (14 males and 9 females) were included. At 24 months of age, their body weight, height at withers and cannon bone circumference was determined. In males, the external genitalia were examined, testis size was measured by transcutaneous ultrasound. The total testicular volume (TTV) was calculated. In females, a transrectal ultrasound examination of the genital tract was performed, the presence of corpora lutea was detected via plasma progesterone concentration and the antral follicle count (AFC) was assessed. Statistical comparisons weremade by analysis of variance (general linear model) with group (blue light vs. control) and sex (male vs. female) as between subject factors (IBM SPSS 27). Results are given as mean ± SEM. There were no group or sex differences with regard to bodyweight or height at the withers. The cannon bone circumference was larger in male vs. female horses (p<0.001) but not affected by blue light treatment during pregnancy. Testes were classified as normal in size and location (Love et al., J Reprod Fertil Suppl 1991;44:99-105) in 13 of 17 blue light and 11 of 14 control colts (n.s., chi2 analysis). The TTV was 232±14cm3 in the blue light and 218±11cm3 in the control group (n.s.). Abnormal testicular development was diagnosed in 7 males with unequal testicular size in 3 blue light and 2 control animals, both testes too small (1 blue light) or unilaterally cryptorchid (1 control). In females, no abnormalities were present. A corpus luteum (progesterone >1ng/ml) was present in 8 / 9 females from the blue light and 5 / 8 from the control group. The AFC was 20.6±2.5 in blue light and 22.1±3.7 in control females (n.s.). Results demonstrate that blue LED light treatment of pregnant mares has no detrimental effects on body and genital tract development of their offspring at two years of age.

Effects of source of supplementary trace minerals in pre- and postpartum diets on reproductive biology and performance in dairy cows

Our objectives were to evaluate the effects of complete replacement of inorganic salts of trace minerals (STM) with organic trace minerals (OTM) in both pre- and postpartum diets on ovarian dynamics, estrous behavior measured by sensors, preimplantation conceptus development, and reproductive performance in dairy cows. Pregnant cows and heifers (n = 273) were blocked by parity and body condition score and randomly assigned to either STM or OTM diets at 45 ± 3 d before their expected calving. Pre- and postpartum diets were formulated to meet 100% of recommended levels of each trace mineral in both treatments, taking into consideration both basal and supplemental levels. The final target concentrations of Co, Cu, Mn, Se, and Zn were, respectively, 0.25, 13.7, 40.0, 0.3, and 40.0 mg/kg in the prepartum diet, and 0.25, 15.7, 40.0, 0.3, and 63.0 mg/kg in the postpartum diet. The STM group was supplemented with Co, Cu, Mn, and Zn sulfates and sodium selenite, while the OTM group was supplemented with Co, Cu, Mn, and Zn proteinates and selenized yeast. Treatments continued until 156 d in milk (DIM) and were assigned to individual cows using automatic feeding gates. Starting at 21 DIM, ultrasonography examinations of the ovaries were performed weekly to determine the presence of a corpus luteum and postpartum resumption of ovarian cyclicity. Cows were presynchronized with 2 injections of PGF2α at 42 and 56 DIM. Estrous behavior was monitored using electronic activity tags that indirectly measured walking activity. Cows detected in estrus after the second PGF2α were inseminated, and those not detected in estrus by 67 DIM were enrolled in a synchronization program. Cows that returned to estrus after artificial insemination (AI) were reinseminated. Pregnancy diagnosis was performed 33 d after AI, and nonpregnant cows were resynchronized. Transcript expression of interferon-stimulated genes in peripheral blood leukocytes was performed in a subgroup of cows (STM, n = 67; OTM, n = 73) on d 19 after AI. A different subgroup of cows (28 STM, 29 OTM) received uterine flushing 15 d after AI for recovery of conceptuses and uterine fluid for analyses of transcriptomics and metabolomics, respectively. In addition, dominant follicle diameter, luteal size and blood flow, and concentration of progesterone in plasma were measured on d 0, 7, and 15 relative to AI. After flushing, PGF2α was given and the dominant follicle was aspirated 2 d later to measure the concentration of trace minerals by mass spectrometry. Estrous behavior, size of the dominant follicle and corpus luteum, concentration of progesterone, time to pregnancy, and proportion of cows pregnant by 100 d of the breeding period did not differ between treatments. A greater proportion of cows supplemented with OTM had a corpus luteum detected before presynchronization (64.3 vs. 75.2%), and primiparous cows supplemented with OTM tended to resume cyclicity earlier than their STM counterparts. Cows supplemented with OTM had a greater concentration of Cu in follicular fluid than cows supplemented with STM (0.89 vs. 0.77 µg/mL, respectively). In pregnant multiparous cows, expression of receptor transporter protein 4 in peripheral blood leukocytes was 42% greater in the OTM group. Conceptuses of the 2 treatments had 589 differentially expressed transcripts, with many indicating advanced conceptus elongation and greater transcript expression of selenoproteins in the OTM group. In pregnant cows, 24 metabolites were more abundant in the uterine fluid of OTM, including spermidine, sucrose, and cholesterol. In conclusion, replacing STM with OTM caused modest improvements to resumption of ovarian cyclicity and important changes in preimplantation conceptus development, but it did not alter conception risk and pregnancy rate.

31 Correlation of the Reproductive Microbiome and Cytokine Profiles with Plasma Progesterone Concentrations in Postpartum Beef Cows Prior to Timed Artificial Insemination

Abstract Female sex steroid hormones have been shown to interact with cytokines within the immune system to help influence fertility. Previous research has indicated that shifts in commensal bacteria are associated with compromised reproductive performance during the postpartum period, yet evaluation of how the female sex hormone progesterone (P4) influences these microbial shifts is not fully understood. The objectives of this study were to determine 1) the relationship between P4 concentrations and cytokine concentrations, and 2) the relationship between P4 concentrations and the reproductive microbiome. Twenty Bos indicus-influenced beef cows (~60 days postpartum and free of health issues) were weighed, body condition scored and then subjected to the Bos indicus prostaglandin 5 day (d) + CIDR protocol beginning on d -8 and timed artificially inseminated on d 0. Blood samples were collected on d-3, -1, 0, and 28. Cytokines and reproductive microbiome were evaluated using vaginal and uterine flushes collected on d -3 and d-1. Experimental groups were assigned by d 28 pregnancy status, determined by transrectal ultrasonography, resulting in Open (n = 13) and Pregnant (n = 7) females. Bacterial community analyses were conducted targeting the V4 hypervariable region of the 16S rRNA gene. Plasma P4 concentrations on d -3 and d -1 were quantified per manufacturers’ instructions using a double-antibody RIA kit. Cytokine analyses of plasma and flushes were conducted using the RayBiotech Quantibody Bovine Cytokine Array Q1 kit per the manufacturer’s instructions. Statistical analyses were conducted using the GLM procedure and CORR procedure in SAS. Plasma P4 concentrations did not differ by pregnancy status (P &amp;gt; 0.05) but did decrease from d -3 to d -1 (0.89 vs. 0.08 ± 0.23 ng/mL, respectively; P = 0.02). There were no significant correlations between plasma P4 and plasma cytokines (P &amp;gt; 0.05). Interferon-alpha (IFNα) and P4 concentrations were positively correlated in Open and Pregnant uterine flushes (r = 0.41; P = 0.01). Concentrations of P4 interleukin (IL)-1F5 were negatively correlated in Open and Pregnant vaginal flushes (r = -0.32; P = 0.04). The relative abundance of genus Methanobrevibacter in uterine flushes was positively correlated with P4 concentrations in both experimental groups (r = 0.35; P = 0.02). Within vaginal flushes, there was a tendency for a negative correlation between the relative abundance of genus Bacteroides and P4 concentrations (r = -0.31; P = 0.05). Alternatively, there is a positive correlation between P4 concentration and relative abundance of genus Streptococcus (r = 0.47; P = 0.01) and genus Methanobrevibacter (r = 0.37; P = 0.02) in vaginal flushes. These results suggest there may be relationships between several cytokines and circulating P4 concentrations; therefore, potentially suggesting immunomodulatory activities of P4. Overall, this research alludes to P4 having a vital role in reproductive microbial shifts and associated immune responses. Further investigation on the local effects of P4 within the reproductive tract on immune responses and bacterial shifts could provide greater insight into mechanisms to improve fertility in beef cattle.

55 Investigating the Potential Benefits of an Immunostimulant (Mycobacterium Cell Wall Fraction) Treatment on Increased Pregnancy Success of Embryo Transfer Recipients

Abstract Modulating the vaginal and uterine microbiome through the use of immunostimulants has the potential to improve fertility in cattle. The object of this study was to evaluate the potential benefits of an immunostimulant, mycobacterium cell wall fraction (MCWF), to increase pregnancy success of embryo transfer (ET) recipients. The three main objectives of this study were: determining if injecting ET recipient cows with MCWF increased proportion of cows with a corpus luteum (CL) on ET day, identifying differences in CL volume and progesterone concentration at the time of ET, and determining if ET recipients that received MCWF have greater pregnancy rate. A total of 926 beef cows at eight different locations were enrolled in this study. Primiparous and multiparous cattle were enrolled in a 7-day CO-Synch + CIDR estrous synchronization protocol. During this protocol, cows received an injection of GnRH (100-μg) at CIDR (controlled internal drug release) insertion [d -9], a prostaglandin F2α injection (25 mg), and CIDR removal [d-2] followed by another injection of GnRH (100 μg; d 0) within 60-66 hours after CIDR removal. At each location at (d 0), cows were sorted based on BCS and days post-partum and randomly assigned to one of two treatments: 1) MCWF- a single intramuscular injection (5 mL) of MCWF at (d 0; Amplimune, NovaVive Inc.; n = 452) or 2) Control- a single intramuscular injection (5 mL) of saline (n = 474). Seven days after (d 7), cows were examined by ultrasonography to determine if a CL was present. Recipient cows that had a CL received ET with a frozen or fresh in vivo or in vitro produced embryo in the ipsilateral uterine horn to the CL, with embryo type and grade balanced between treatments. Blood samples were collected in one location (n = 98) for analysis of plasma concentration of progesterone on (d 7) ET day. Pregnancy diagnosis was then performed by ultrasonography between 30 and 90 days of gestation. Data were analyzed using the GLIMMIX and MIXED procedures of SAS. Cow BCS and days postpartum were similar (P &amp;gt; 0.10) between treatments (5.5 ± 0.6 and 103 ± 14 days, respectively). Recipient cow utilization rate was similar between treatments (P = 0.49; 81.2 ± 0.42%). At the time of ET MCWF had larger CL than Control cows (5,768.6 ± 133.7 and 5,408.0 ± 128.5 mm3, respectively, P = 0.03). and increased progesterone concentration (2.68 ± 0.17 and 2.18 ± 0.14 ng/mL, respectively, P = 0.01). However, pregnancy rate to ET was similar (P = 0.922) between treatments (60.9 and 61.3 ± 0.05% for Control and MCWF, respectively). In conclusion, treatment of ET recipient cows with MCWF increased CL volume and concentration of progesterone at the time of ET but failed to generate greater pregnancy rates.

Effect of early administration of progesterone on the function of the corpus luteum of llamas

The aim of the present study was to evaluate if early administration of progesterone immediately after ovulation affects corpus luteum lifespan in llamas. Female llamas (n = 16) were induced to ovulate by Buserelin injection in the presence of an ovulatory follicle (Day 0). On Day 2, ovulation was confirmed and animals were randomly divided into two groups: treated animals (n = 8) received an intravaginal device containing 0.3 g of progesterone from Day 2 to Day 6 post-induction of ovulation and control group (n = 8) received a device with 0 g of progesterone. Blood samples were collected daily to determine plasma progesterone concentration and transrectal ultrasonographies were performed from Day 7 to Day 12 post-induction of ovulation. Mean maximum diameter of the corpus luteum was significantly lower and was reached before in the treated group than in the control group. The mean highest plasma progesterone concentration and the day that concentration was achieved were similar between groups. However, mean plasma progesterone concentration was significantly higher in the treated group than in the control group on Days 3 and 4 and lower on Days 8 and 9 post-induction of ovulation. The day that plasma progesterone concentration returns to 1 ng/ml differed between groups, occurring earlier in the treated group. In conclusion, the early increase of plasma progesterone concentration during the luteal phase, promoted the premature activation of the luteolytic process affecting corpus luteum function in llamas as it was previously reported in other species.

Cystic ovarian disease in dairy cattle: Diagnostic accuracy when using B-mode and color Doppler ultrasound

The most frequently reported definition of cystic ovarian disease in cattle is an abnormally persistent follicle (>7 to 10 d) with a diameter >25 mm. Discrimination between luteal and follicular ovarian cystic structures has traditionally been conducted by measuring the rim width of luteal tissue. The most common practice used in the field for diagnosis of cystic ovarian disease is examination by rectal palpation with or without the use of a B-mode ultrasound. Color Doppler ultrasound technology allows assessment of blood flow area measurements in the ovary, which has been proposed as a potential indirect measure for plasma progesterone (P4) concentrations. The objective of this study was to compare the diagnostic accuracy of differentiating luteal structures from follicular ovarian cysts using measures collected with B-mode and color Doppler transrectal ultrasonography. The definition of an ovarian cyst was a follicle greater than 20 mm in diameter in the absence of a corpus luteum that persisted for at least 10 d. A 3-mm luteal rim width was used to differentiate follicular and luteal cysts. A total of 36 cows were enrolled in the study during routine herd reproductive examination visits, with 26 and 10 having follicular and luteal cysts, respectively. Cows enrolled in the study were examined using a Mini-ExaPad mini ultrasound with color Doppler capabilities (IMV Imaging Ltd.). Blood samples were collected from each cow to measure P4 serum concentrations. History and signalment of each cow, including days in milk, lactation, times bred, days since last heat, milk composition, and somatic cell counts, were retrieved from an online database (DairyComp 305, Valley Agricultural Software). The accuracy of diagnosing follicular from luteal cysts based on luteal rim thickness was analyzed by receiver operating characteristic (ROC) curve using P4 as the gold standard, where P4 concentrations exceeding 1 ng/mL was defined as luteal, and all other structures with less P4 were considered follicular. Luteal rim and blood flow area were selected for further analysis because they presented the best ROC curves for differentiating cystic ovarian structures, with areas under the curve of 0.80 and 0.76, respectively. Luteal rim width of 3 mm was used as the cutoff standard in the study, resulting in sensitivity and specificity of 50% and 86%, respectively. Blood flow area of 0.19 cm2 was used as the cutoff standard in the study, resulting in sensitivity and specificity of 79% and 86%, respectively. When combining the use of luteal rim width and blood flow area to differentiate cystic ovarian structures, a parallel approach resulted in sensitivity and specificity of 73% and 93%, respectively, whereas an in-series approach resulted in sensitivity and specificity of 35% and 100%, respectively. In conclusion, the use of color Doppler ultrasonography when discriminating between luteal and follicular ovarian cysts in dairy cattle resulted in higher diagnostic accuracy compared with using B-mode ultrasonography alone.

The Temporal Associations of B-Mode and Power-Doppler Ultrasonography, and Ovarian Steroid Changes of the Periovulatory Follicle and Corpus Luteum During Luteogenesis and Luteolysis in Jennies.

This study aimed to determine the associations between B-mode and Power-doppler ultrasonography and ovarian steroids of the periovulatory follicle and respective corpus luteum (CL) during luteogenesis and luteolysis in jennies. Twenty-four periovulatory follicles/estrus of correspondent one inter-ovulatory interval (n=12 jennies) were assessed in the study. B-mode ultrasonography and teasing were carried out once day until the detection of a periovulatory follicle (≥28 mm, uterine edema, and signs of estrus). Thereafter, jennies were monitored at 4-hour-intervals by B-mode and Power-doppler ultrasonography. Closer to ovulation, jennies were hourly checked. Each CL was checked daily from luteogenesis to luteolysis. Plasma concentrations of estradiol and progesterone were assessed daily with chemiluminescence immunoassay. Granulosa echogenicity and thickness increased from -36 hour to -1 hour before ovulation in 70% of follicles (P < .05) and were strongly associated with impending ovulation (r=0.80 and r=0.70, respectively). The follicular-wall blood flow increased from -72 to -24 hour pre-ovulation, while the estradiol concentration declined from 42 pg/mL by -72 hour to 31.6 pg/mL by 24 hour before ovulation (P < .05). The vascularization of the periovulatory follicle decreased from 62% (-36 hour) to 37% (-1 hour) before ovulation (P < .05). The CL vascularization and progesterone concentration gradually increased, reaching the peak at 11- and 10-day after the ovulation, respectively (P < .05). The CL vascularization started to decline 3 day before luteolysis, while progesterone concentrations started to drop 4 day before luteolysis (P < .05). In conclusion, the structural changes of the periovulatory follicle detected on B-mode and Power-doppler can be used to detect impending ovulation in donkeys; however, Power-doppler, but not B-mode ultrasonography, can be used to assess CL function in jennies.

Effect of body condition score on biochemical parameters and hormonal profiles during the mating period in Ouled Djellal ewes in arid zone

ABSTRACTThis study aims to evaluate the effect of body condition score (BCS) on hormonal profiles and to reveal their influence on the blood metabolites in Ouled Djellal ewes during the mating period. The experiment was conducted on thirty, clinically healthy and non-pregnant, Ouled Djellal ewes which have been kept into two groups according to their body condition score (Group I: BCS &lt; 2.50 units; n = 13, Group II: BCS &gt; 2.50 units; n = 17). In both groups, oestrus was synchronized using hormonal patterns then the ewes were left to be naturally inseminated. Blood samples were collected at the time of the sponge removal. Plasma concentrations of glucose, triglycerides, cholesterol, total protein, albumin, creatinine, urea, triiodothyronine, thyroxine and Progesterone were recorded. The plasma level of triglycerides and thyroid hormones (T3 and T4) increase significantly (P &lt; 0.01) in group II. Progesterone concentrations were similar (P ≥ 0.05) in both groups at mating period, although we recorded higher rate in group I. Therefore, we conclude that body condition score has a significant impact on some hormone profiles and blood parameters during the mating period.

Relationship between ovarian ultrasonographic findings on the seventh post-estrus day and plasma progesterone concentration, nutritional metabolic factors, and pregnancy outcome in dairy cows.

To improve the accuracy of ultrasonographic assessment of luteal function, we investigated the relationship between ovarian ultrasonographic findings on Day 7 (Day 1 = ovulation) and plasma progesterone (P4) concentration, nutritional metabolic factors, and pregnancy outcome. A total of 47 spontaneous estrus events were investigated in 38 lactating Holstein cows (artificial insemination, n = 31; embryo transfer, n = 16). Transrectal ultrasonography was performed on Days 0 and 7 to measure the pre-ovulatory follicle area on Day 0 and the luteal tissue area (LTA), luteal blood flow area (LBF), relative LBF (rLBF) (= LBF/LTA), and dominant follicle area (DFA) on Day 7. Blood samples were collected on Day 7 to measure plasma P4, insulin-like growth factor-I (IGF-I), insulin, and metabolites. Plasma P4 concentration was positively correlated with LTA but was not associated with LBF or rLBF. Plasma P4 concentration was positively correlated with blood glucose and IGF-I and negatively correlated with blood urea nitrogen and free fatty acid, and no significant relationship was found between the ultrasonographic findings of the corpus luteum (CL) and these blood metabolites. Pregnant cows had smaller DFA than non-pregnant cows. In conclusion, LTA measurement can help predict plasma P4 concentration, but it was difficult to detect variations in plasma P4 concentration in relation to changes in energy status by evaluating the CL ultrasonographically. A combined assessment of CL and first-wave dominant follicle may be important in evaluating fertility.

Blood hormone concentrations as markers and predictors of porcine meat production and quality?

Context The applicability of hormones in the prediction of meat production in non-ruminant species has been poorly examined. Aims To examine the applicability of plasma concentrations of leptin, estradiol, progesterone and insulin-like growth-factor I (IGF-I) for characterisation and early prediction of the production and quality of meat in gilts. Methods Animals were compared at 150 days of age with below (‘low’) and above (‘high’) median hormone concentrations and their traits of meat production and quality at the age of 200 days. Key results Animals with a high leptin concentration in blood at the age of 150 days had higher slaughter and carcass weights and weight of ham, but a lower lean meat content at the age of 200 days, than did the gilts with a low leptin concentration. Animals with a high estradiol concentration had a higher carcass weight, weight of ham and backfat thickness and a lower electrical conductivity of musculus semimembranosus than did animals with a low estradiol concentration. High blood IGF-I concentration was associated with a higher slaughter weight, carcass weight and lean meat content. No significant differences between the animals with ‘high’ and ‘low’ progesterone concentration and meat characteristics have been found. Conclusions These observations confirm the involvement of leptin, IGF-I and estradiol in up-regulation of meat production in pigs. Furthermore, they suggest that leptin can be useful for characterisation and prediction of fat production, whereas IGF-I and estradiol (but not progesterone) could be both markers and predictors of porcine growth and meat production. Implications The blood concentrations of these hormones could help in characterisation and selection of pigs for meat production.

Ovarian and uterine haemodynamics during the estrous cycle of Egyptian buffaloes in relation to steroid hormonal and nitric oxide levels

The present investigation aimed to study the ovarian and uterine haemodynamics during the estrous cycle in buffaloes in correlation with the hormonal changes (estradiol and progesterone) and nitric oxide. Six cyclic buffalo cows were scanned via transrectal Doppler ultrasonography to evaluate the normal ovarian and uterine haemodynamics through three successive estrous cycles. Results showed that the dominant follicle (F1) area, F1 diameter, area, antrum area, coloured area (pixels) and colour area % attained the highest values (P&lt;0.0001) during the follicular phase. The vascularisation of F1 tended to be higher (P&gt;0.05) on the day of ovulation (Day 0). The diameter and the vascularisation of the corpus luteum (CL) reached peak values (P&lt;0.0001) at Day 14 and decreased to minimum values at Day 21. Plasma progesterone (P4) concentrations correlated positively with the diameter of CL (r ≤ 0.37; P≤0.01), CL area (r≤0.35; P≤0.009), and CL colour area (pixels) (r≤0.39; P≤0.001). Besides, the estradiol (E2) level correlated with F1 diameter (r≤0.19; P≤0.0001) and F1 area (r≤0.18; P≤0.0001). Peak systolic velocity (PSV) of the ipsilateral ovarian (P≤0.082) and uterine (P≤0.024) arteries were higher than those obtained for the contralateral ones. A similar finding was obtained in end-diastolic velocity (EDV) of the ovarian arteries (P≤0.005). In conclusion, the blood flow of the ovary and uterus recorded in buffaloes varied according to the ovulating ovary, day and phase of the estrous cycle as well as with the hormonal changes.

Effect of dietary betaine on endocrine profile in postpartum lactating Murrah buffaloes during hot-humid season

Extreme heat along with metabolic stress associated with the postpartum period negatively affects the endocrine status of animals. Betaine is a feed additive that promotes animal growth. Since betaine contains three methyl groups, it acts as a methyl donor in animal metabolism. Eighteen postpartum Murrah buffaloes were randomly divided into T1 Group (Control), T2 and T3 Group was supplemented with betaine 50 g/animal/day and 100 g/animal/day respectively from 5th day postpartum and was continued up to 4 months postpartum. On day 50 postpartum the mean value of plasma cortisol of T1 Group was maximum followed by T2 Group and T3 Group had minimum plasma cortisol mean value which differed (P&lt;0.05) significantly between groups. The mean concentration of plasma T3 total, T4 total, progesterone and estrogen showed (P&gt;0.05) non-significant difference between all the groups. However, betaine fed T2 and T3 Group had higher plasma T3, T4, progesterone and estrogen as compared to control, it might be due to the effect of betaine, which reduces metabolic stress and activate hypothalmo-pituitary and gonadal axis after parturition and lactation period during heat stress.

Effects of Intra-Uterine Fluid Accumulation after Artificial Insemination on Luteal Function in Mares

After breeding or artificial insemination, especially with frozen/thawed semen, mares often develop a persistent uterine inflammation, which is diagnosed by intra-uterine fluid accumulation. Here, we explored whether intra-uterine fluid accumulation affects corpus luteum function and tested the hypothesis that intra-uterine fluid accumulation after artificial insemination alters blood flow in the corpus luteum and plasma progesterone concentrations. A total of 40 Standardbred mares were artificially inseminated with frozen-thawed semen 30 to 36 h after induction of ovulation, and cases with or without intra-uterine fluid accumulation were detected by ultrasound 12 h after insemination. Luteal blood flow was measured by Power Doppler ultrasonography 3 and 6 days after ovulation, progesterone concentration was measured in peripheral plasma by ELISA 6 days after ovulation, and pregnancy was diagnosed by ultrasonography 14 days after ovulation. Luteal blood flow increased between 3 and 6 days after ovulation, but blood flow did not differ significantly between cases with (n = 28) and without (n = 25) intra-uterine fluid accumulation after insemination. Surprisingly, progesterone concentrations were higher in cases of intra-uterine fluid accumulation than cases without (9.3 ± 1.1 vs. 6.6 ± 0.5 ng/mL, p = 0.048). Pregnancy was less likely in cases with intra-uterine fluid accumulation than in cases without (10/28 vs. 17/25, p = 0.019), and there was a negative correlation between the severity of intra-uterine fluid accumulation and per cycle pregnancy rate. These data suggest that although intra-uterine fluid accumulation increases the secretion of progesterone, pregnancy is more dependent on uterine health than ovarian function.

Reproductive and lactational responses of multiparous dairy cattle to short-term postpartum chromium supplementation during the summer months

The objective of this work was to evaluate the potential benefits of short-duration, high-dose chromium (Cr) supplementation in early postpartum dairy cows during the summer months. Multiparous, early-lactation cows (20.95 ± 0.21 d in milk) were assigned to 1 of 2 treatment groups: (1) control diet (Con; n = 10) or (2) control diet + Cr propionate (CrPro; 12 mg/head per day Cr; n = 12). Measurements of ovarian structures, respiration rates (RR), rectal temperatures (RT), and blood glucose concentrations were recorded every 3 d. Blood was also collected for analysis of plasma progesterone concentrations. Every 6 d, in conjunction with ultrasonography, endometrial cytology samples were collected via cytobrush from each cow to determine the incidences of subclinical endometritis, as determined by polymorphonuclear leukocyte (PMNL)%. No differences were detected in RR, RT, blood glucose, feed intake, milk yield, or change in body weight. The supplementation did, however, improve some reproductive parameters. At cytology sample 6, the PMNL% increased in Con cows, and was greater than the PMNL% in the CrPro group. Chromium consumption did not affect the number or size of most follicles, with the exception being the 6 to 9 mm category where the CrPro group had a greater average diameter and tended to have greater numbers of follicles in this category. While corpus luteum numbers and size did not differ between treatments, the ratio of progesterone to average corpus luteum volume was greater in the CrPro group compared with the Con group. The results from this study indicate that, whereas the short-term, high-dose supplementation strategy did not affect feed intake or milk yield, this Cr supplementation strategy could benefit reproductive performance during periods of stress.

Low plasma progesterone concentration during the early luteal phase delays endometrial development and the beginning of placentation in mares

While detrimental effects of reduced plasma progesterone concentration in the early luteal phase on conceptus development in horses have recently been demonstrated, there is no information on associated effects on the endometrium, allantochorion (AC), and chorionic girdle (CG) in this species. We hypothesised that reduced early postovulatory progesterone concentration in pregnant horses is detrimental to endometrial function and development of the embryonic membranes and is an underlying cause of delayed conceptus development. After insemination and ovulation, mares (n = 11) were assigned to treatment (TREAT) or control (CON) during two pregnancies. In TREAT pregnancies, mares received a PGF2α analogue for four consecutive days starting on the day of ovulation with the aim to reduce progesterone secretion. Mares were left untreated in CON pregnancies and thus served as their own controls. Endometrial biopsies for analysis of histomorphology, epidermal growth factor (EGF) and EGF receptor (EGFR) mRNA and protein expression in the endometrium, AC, and CG as well as abundance of regulatory T lymphocytes (Tregs) were collected on day 34 of pregnancy. Histomorphometric analysis revealed a higher luminal endometrium and a higher CG epithelium in CON compared to TREAT pregnancies. Abundance of mRNA for EGF and EGFR was large in the endometrium, AC and CG but did not differ between TREAT and CON pregnancies. The number of endometrial regulatory T lymphocytes was reduced in TREAT compared to CON pregnancies, adding further aspects to the potentially detrimental effects of reduced progesterone concentrations on equine pregnancy.

The first week following insemination is the period of major pregnancy failure in pasture-grazed dairy cows.

A 60% pregnancy success for inseminations is targeted to optimize production efficiency for dairy cows within a seasonal, pasture-grazed system. Routine measures of pregnancy success are widely available but are limited, in practice, to a gestation stage beyond the first 28 d. Although some historical data exist on embryonic mortality before this stage, productivity of dairy systems and genetics of the cows have advanced significantly in recent decades. Accordingly, the aim was to construct an updated estimate of pregnancy success at key developmental stages during the first 70 d after insemination. Blood samples were collected for progesterone concentrations on d 0 and 7. A temporal series of 4 groups spanning fertilization through d 70 were conducted on 4 seasonal, pasture-grazed dairy farms (n = 1,467 cows) during the first 21 d of the seasonal breeding period. Morphological examination was undertaken on embryos collected on d 7 (group E7) and 15 (group E15), and pregnancy was diagnosed via ultrasonography on approximately d 28 and 35 (group E35) as well as d 70 (group E70). Fertilization, embryo, and fetal evaluation for viability established a pregnancy success pattern. Additionally, cow and on-farm risk factor variables associated with pregnancy success were evaluated. We estimated pregnancy success rates of 70.9%, 59.1%, 63.8%, 62.3%, and 56.7% at d 7, 15, 28, 35, and 70, respectively. Fertilization failure (15.8%) and embryonic arrest before the morula stage (10.3%) were the major developmental events contributing to first-week pregnancy failures. Embryo elongation failure of 7% contributed to pregnancy failure during the second week. The risk factors for pregnancy success that were related to the cows included interval between calving and insemination, and d-7 plasma progesterone concentrations, whereas insemination sire was associated with pregnancy outcome. Most pregnancy failure occurs during the first week among seasonal-calving pasture-grazed dairy cows.

Assessment of placental complex function and miscarriage prevention in pregnant women with uterine fibroid

The objective: to reduce the frequency of the threat of pregnancy interruption and loss in women with uterine fibroid through treatment prediction and improvement.Materials and methods. A complex examination of 70 pregnant women with uterine fibroid at 15-16 weeks of pregnancy (main group) and 50 pregnant women without uterine fibroid at the same gestational term (control group) was carried out at 4 clinical bases of the Department of Obstetrics and Gynecology N1 of the Shupyk National Healthcare University of Ukraine in the time period of 2020-2022. Pregnant women in the main group were divided into 2 subgroups depending on the type of the nodes: Ia – 39 pregnant women with subserous type of fibroid nodes (type 5-6 according to FIGO) and Ib – 31 pregnant women with intramural fibroid (type 3-4 according to FIGO). The pregnant women in the main group received the complex of developed therapy for pregnancy interruption (micronized progesterone, magnesium preparations, vitamin B6, acetylsalicylic acid), in the control one – the common therapy (bed rest, abstinence from sexual life, micronized progesterone preparations, tranexamic acid).The concentrations of estradiol, progesterone, human chorionic gonadotropin (hCG) were determined in the blood plasma of all persons at 15–16 weeks and 24 weeks of pregnancy.Results. In the II trimester the concentration of estradiol in the blood of pregnant women with intramural uterine fibroid, especially with multiple forms, was significantly higher than in the control group (p&lt;0.05). At the same time, in pregnant women with intramural fibroid node(s) the mean concentration of estradiol exceeded the similar indicator in the group with the subserosal type (p&lt;0.05). These changes indicated the stress of the hormonal function of the placenta and were considered by us as one of the signs of the initial stage of placental dysfunction.With an increase in estradiol concentration, a significant decrease in progesterone amount was noted. Progesterone deficiency was significantly more common in the subgroup of pregnant women with multiple intramural uterine fibroid and nodes in contact with the uterine cavity, especially at the place of placenta attachment (type 3) – 165.24±14.71nmol/l compared to the control group – 219.96±16.63 nmol/l, and with pregnant women with subserosal node(s) – 210.61±18.57 nmol/l (р&lt;0.01), which confirms the threat of abortion and indicates the development of placental dysfunction. In the II trimester of pregnancy the concentration of hCG in women with uterine fibroid was significantly lower than in women without uterine fibroid and especially lower in multiple uterine fibroid. In the women of the main group progesterone and hCG concentrations in the blood plasma normalized (p&gt;0.05) after the treatment, but the level of estradiol in the group of pregnant women with multiple intramural uterine leiomyoma remained significantly higher (p&lt;0.05).Conclusions. Pregnant women with uterine fibroid have an increased risk of placental dysfunction with a disbalance of the main placental hormones: an increase in estradiol concentration and a relative decrease in progesterone and human chorionic gonadotropin, a shift in the estrogen-progesterone balance towards relative hyperestrogenia.The use of medical measures with long-term support with progesterone, magnesium and low doses of acetylsalicylic acid for the prevention of miscarriage in persons with the clinical manifestations of the threat of gestation is quite effective.

The post-ovulatory rise in progesterone is lower and the persistence of oestrous behaviour longer during the first compared with the second cycle of the breeding season in mares.

Mares are seasonally polyoestrous breeders. Therefore, the first ovulation of the season, following winter anoestrus, is the only cycle in which mares ovulate without the presence of an old CL from the previous cycle. The objective of this study was to compare the length of oestrous behaviour, and plasma progesterone concentrations during the early post-ovulatory period between mares after the first and second ovulation of the breeding season. Overall, 38 mares and 167 oestrous periods were used in the study. From those, 11 mares were used during the first and subsequent oestrous period to measure and compare the post-ovulatory rise in progesterone concentration, whereas all the mares were used to compare the length of the post-ovulatory oestrous behaviour between the first and subsequent cycles of the breeding season. The persistence of the post-ovulatory oestrus was longer (p< .001) following the first ovulation of the year (median of 52 h) compared with the subsequent ovulations (median of 36 h for second and later ovulations groups; n= 38 mares). The progesterone concentration at any of the four 8h-intervals analysed (28, 36, 76 and 84 h post-ovulation) was lower (p< .01) following the first versus the second ovulation of the year. By 36 h post-ovulation the progesterone concentration of mares at the second ovulation of the year had passed the threshold of 2ng/ml (2.1± 0.33 ng/ml), whereas in the first cycle it was 1.2± 0.13 ng/ml. In conclusion, mares had lower progesterone concentrations in their peripheral circulation and longer persistence of oestrous behaviour following the first ovulation of the year compared with the second and subsequent ovulatory periods of the breeding season.

Current knowledge about the processes of luteolysis and maternal recognition of pregnancy in camelids.

Camelids have many unique reproductive features that considerably differ from those of other domestic species. Females are induced ovulators with subsequent development of a corpus luteum (CL) with a short lifespan. Plasma progesterone concentration starts to increase on day 4, peaks on day 8-9 and, in non-pregnant animals, basal concentration is reached around day 10-11 post-induction of ovulation. Luteolytic pulses of prostaglandin F2α (PGF2α ) are firstly detected on day 7 or 8 (approximately on day 5-6 after ovulation), with maximal luteolytic peaks observed between days 9 and 11 post-mating, in coincidence with a high endometrial expression of cyclooxygenase 2, a limiting enzyme in prostaglandins synthesis. Unlike other species, oxytocin seems not to be involved in the luteolytic process in these species. The CL is the main source of progesterone secretion, and its function is required to support pregnancy. Despite constant research efforts, aspects of reproduction and maternal recognition of pregnancy in camelids remain not fully understood. A transient decrease and subsequent recovery in plasma progesterone concentration are observed after day 9 post-mating in pregnant animals in association with a pulsatile release of PGF2α and a transitory decrease in CL vascularization. Thus, embryo recognition should occur between days 8 and 12 post-mating. In camels, conceptus tissues exhibit aromatizing activity with the capacity to synthesize large amounts of oestradiol. Similarly, llama blastocysts secrete oestradiol-17β during the preimplantation stage, with a higher production during the elongation period. An increase in the endometrial expression of oestrogen receptor α is also observed on day 12 post-mating. All these evidences suggest that oestrogen could be the signal released by the embryo at the time of its recognition in camelids. Besides, nearly 98% of pregnancies are carried out in the left horn. A decrease in the endometrial expression of mucin 1 and 16 genes has been reported, suggesting that these changes are crucial for successful embryo implantation; however, no differences have been observed between horns. Thus, maternal recognition of pregnancy in camelids is a particularly complex process that must occur in a concise time to allow the rescue of the CL and embryo survival.

Effect of methanolic extract of Spondias mombin on oestrous cycle, conception rate and gestation in rabbits

Effect of Spondias mombin (SM) on oestrous cycle, conception and pregnancy was evaluated in 25 sexually mature Chinchilla rabbit does (Mean weight: 1.94 ± 1.06kg). In phase one, fifteen rabbits were synchronized with FSH (2 mg/kg i.m.) 12 hourly for three days. They were randomly assigned into three groups of five rabbits each. Group 1 and 2 received 1ml saline solution and 800mg/kg of methanolic extract of SM (meSM) orally for thirty days respectively. Group 3 received a single treatment of melengesterol acetate (MGA; 50mg/kg i.m.). Blood was obtained from the jugular vein at ten days interval for thirty days to determine plasma concentration of LH, FSH, estrogen and progesterone. Thereafter, the does were mated and laparotomised was carried out one week after to determine the number of embryonal sacs. In phase two, ten does were mated and ultrasonographically confirmed to be pregnant seven days post-mating. They were treated with 800mg/kg meSM orally at ten and twenty days post-mating. The does were observed daily until they kidded or aborted. Data obtained were analysed using student’s T-test and ANOVA, with significance set at P ≤ 0.05. Mean values of LH and Progesterone significantly decreased in Group 3 and 2 compared to control group while FSH was lower significantly in Group 3 compared to other groups. The effect of meSM on oestrous cycle was not so obvious in this study. Administration of meSM 10 days post-mating caused abortion in only one doe and caused no abortion at 20 days post-mating. It was concluded that meSM did not adversely affect reproductive cyclicity and pregnancy but has potential to cause abortion during early pregnancy in Chinchilla rabbits. Further studies where hormonal assays are done more frequently than this study to be able to determine the effect of meSM on oestrous cycle are suggested.