Predicting early pregnancy in Egyptian buffalo cows via measuring uterine and luteal blood flows, and serum and saliva progesterone

Ultrasonography for the detection of pregnancy and study of embryonic and fetal development in camels, buffaloes, and sheep: Techniques, equations, and limitations

New technologies for detecting pregnancy shortly after mating/insemination and identifying gestational age are essential for speeding up the reproductive cycle and ensuring high reproductive efficiency in livestock farming. Ultrasonography can successfully identify pregnancy and determine gestational age in many domestic animals. On the other hand, many herds of camel and buffalo and flocks of sheep are aware of the day of service, making it difficult to appropriately manage pregnant animals. This study provides a review of the literature on various techniques for ultrasonographically diagnosing pregnancy in camels, buffaloes, and sheep, focusing on the most appropriate times to use each technique, the earliest opportunity to diagnose pregnancy, and the possibility of using various parts of the fetus to create mathematical equations to determine gestational age. Some limitations of ultrasonography in pregnancy diagnosis were identified and significant pregnancy events in dromedaries were discussed, including left-horn and twin pregnancies. The data presented here will prove essential for researchers, farmers, and countries that rely heavily on these animals for providing meat, milk, cosmetics, and other animal products to enhance reproduction and production efficiency.

Emotional temperaments in advanced pregnant goats and its relationship with the feto-maternal blood flow and placentome echotexture

The current study aimed to investigate the effect of xylazine sedation (non-sedated versus sedated conditions) and animal temperament on the fetal and maternal hemodynamics during the late stage of gestation in goats. In addition, it aimed to study the concentrations of cortisol and the echotexture of the placentome. Fourteen goats were assigned into two equal groups (n = 7, each) based on the animal's emotional temperament (calm versus nervous groups). All goats were examined for assessment of the blood flow within the fetal aorta (FA), umbilical artery (UMA), and middle uterine artery (MUA) using color-pulsed Doppler ultrasonography. Goats were exposed to light sedation using the recommended dose of xylazine (0.05 mg/Kg Bw) intramuscularly. Goats in each group were reassessed for the studied parameters after sedation. Blood samples were drawn to determine the concentrations of cortisol. Placentome echotexture pixel intensity (PXI) was evaluated using computer image analysis software. Results revealed the significant impact of the xylazine sedation on the Doppler indices of the blood flow within the measured arteries (FA, UMA, and MUA), the PXI of placentome echotexture, and cortisol concentrations. The emotional temperament of goats had significant effects on the blood flow parameters of the MUA and UMA, concentrations of cortisol, and the PXI of the placentome. The interaction effect (sedation x temperament) was noticed in the measured parameters of the UMA blood flow, fetal heart rate, and cortisol concentrations. In conclusion, xylazine sedation and emotional temperaments induced alterations in the echotexture of the placentomes as well as the hemodynamic parameters of late-stage pregnant goats without affecting the pregnancy outcomes.

Effect of pre-treatment of melatonin on superovulation response, circulatory hormones, and miRNAs in goats during environmental heat stress conditions

Environmental heat stress has a deleterious impact on farm animal reproductive performance. The purpose of this study was to see how the addition of melatonin affected the efficacy of the superovulation regimen in goats in hot climatic conditions. Sixteen Shiba goats were synchronized and divided into two equal groups (n = 8, each): the melatonin group, which received a single S/C dose of melatonin, and a control group, treated with one ml of corn oil only. Ultrasonographic assessment of ovarian structures (Graafian follicles; GFs and corpus lutea; CLs) morphometry and hemodynamics were performed during the estrous phase of the superovulation (D0) and at day7 after ovulation (D7) of the superovulation regimen. The peripheral reproductive hormones were measured, and microRNAs were characterized. The mean diameter and the total-colored area of GFs during the D0 were significantly (P˂0.05) higher in the melatonin group (5.42 ± 0.11 mm and 1592.20 ± 45.26 pixels, respectively) compared to the control group (4.62 ± 0.12 mm and 1052.55 ± 29.47 pixels, respectively). Concentrations of LH and E2 increased significantly (P˂0.05) in the melatonin group (1.06 ± 0.06 ng/ml and 46.34 ± 2.77 pg/ml, respectively) compared to the control group (0.75 ± 0.12 ng/ml and 29.33 ± 1.89 pg/ml, respectively). At D7, the melatonin-received goats attained greater values in the mean count (6.75 ± 0.33, P˂0.005), diameters (6.08 ± 0.12 mm, P˂0.01), and total-colored area (17137.30 ± 128.53 pixels, P˂0.01) of detected CLs and progesterone concentrations (4.08 ± 0.24 ng/ml) compared to control goats (4.00 ± 0.28, 4.50 ± 0.19 mm, 11156.87 ± 117.90 pixels, and 2.90 ± 0.18 ng/ml respectively). MiRNA expression analysis was identified during both stages denoting several up and downregulated miRNA candidates among the studied groups. In conclusion, incorporating melatonin enhanced the efficiency of the superovulation regimen in goats under hot climatic conditions.

Incorporation of L-Carnitine in the OvSynch protocol enhances the morphometrical and hemodynamic parameters of the ovarian structures and uterus in ewes under summer climatic conditions

Heat stress negatively impacts the reproductive performance of sheep including the efficiency of estrous synchronization regimens. This study aimed to investigate the potential effects of L-Carnitine (LC) administration on the efficacy of the OvSynch protocol in ewes under summer climatic conditions. Ewes were synchronized for estrus using the OvSynch protocol and a dose of LC (20 mg/kg body weight) was intravenously (IV) administered on the same day of PGF2α injection to one group (n = 8; LC group), while other ewes (n = 8; control group) received the same protocol without LC. Ultrasonographic evaluation (including B-mode, color, and pulsed Doppler) was used to assess the morphometrical and hemodynamic parameters of ovarian structures [number, size, and blood flow of follicles (GFs) and corpora lutea (CLs)] and uterus during the estrous phase (Day 0), and on Day 8 post ovulation (luteal phase). Uterine artery blood flow (MUA) was assessed by measuring the resistive index (RI) and pulsatility index (PI) at both stages. The serum samples were collected to measure the concentrations of estradiol (E2), progesterone (P4), and total antioxidant capacity (TAC) using commercial kits. Results revealed a significant (P<0.05) increase in the colored pixel area of GFs and uterus in the LC group (392.84 ± 31.86 and 712.50 ± 46.88, respectively) compared to the control one (226.25 ± 17.74 and 322 ± 18.78, respectively) during Day 0. Circulating E2 and TAC levels were significantly (P<0.05) higher in the LC-treated ewes (31.45 ± 1.53 pg/ml and 1.80 ± 0.13 mM/L, respectively) compared to those in the control ewes (21.20 ± 1.30 pg/ml and 0.98 ± 0.09 mM/L, respectively) during Day 0. Moreover, LC improved the colored pixel area of CLs (2038.14 ± 102.94 versus 1098 ± 82.39) and uterus (256.38 ± 39.28 versus 121.75 ± 11.36) and circulating P4 (2.99 ± 0.26 ng/ml versus1.67 ± 0.15 ng/ml) on Day 8. Values of RI of MUA were significantly lower in the LC group compared to the control one on Day 0 and Day 8 (0.48 ± 0.03 versus 0.72 ± 0.03 and 0.58 ± 0.03 versus 0.78 ± 0.02, respectively). In conclusion, LC incorporation in the OvSynch protocol enhanced the morphometrical and hemodynamic parameters of the ovarian structures and the uterus concomitantly with improvements in the TAC, E2, and P4 concentrations in ewes under hot summer conditions.

Administration of Estradiol Benzoate Enhances Ovarian and Uterine Hemodynamics in Postpartum Dairy Buffaloes

The postpartum (PP) period is a crucial stage for the resumption of reproductive performance and ovarian cyclicity in dairy buffaloes. The present study aimed, for the first time, to assess the effect of the administration of estradiol benzoate (EB) on ovarian and uterine hemodynamics in PP dairy buffaloes. Eight pluriparous acyclic domestic buffaloes were enrolled in the present experiment and received a dose of 10 mg of estradiol benzoate (EB) intramuscularly 4 weeks after parturition. All animals were examined two times before EB administration (days -3, and -1) and on the day of EB administration (day 0), followed by examinations on days 1, 3, 5, 7, and 9 post-EB administration. The middle uterine artery (MUA) and ovarian artery (OA) blood flow patterns were assessed using a color Doppler ultrasound device. The reproductive parameters were (1) the cross-sectional diameters (cm) of the OA and MUA, (2) cranial uterine horn thickness (UHT; cm), and (3) hemodynamic changes within the MUA on both the ipsi- and contra-lateral sides of the previous pregnant horn and within the OA corresponding to the ovarian tissues. The examined blood flow parameters were the pulsatility index (PI), resistance index (RI), peak systolic/end-diastolic ratio (S/D), time-averaged maximum velocity (TAV; cm/s), uterine blood flow rate (BFR; bpm), and uterine blood flow volume (BFV; mL/min). Concomitantly, blood samples were collected from the coccygeal vein, and the sera were stored at -18 °C for use in estradiol (E2-17β) and nitric oxide (NO) assays. The results revealed increases in both OA and MUA cross-sectional diameter (cm) on the ipsi-lateral and contra-lateral (p < 0.05) sides within 24 h until day 9 post-treatment. The values of the RI and PI of blood flow within the OA and MUA on the ipsi-lateral and contra-lateral sides of the previous pregnancy were obviously lower (p < 0.05) at 24 h after the administration of EB, and then, started to gradually elevate, reaching the pre-treatment values on day 9 after EB administration. Both the BFR and BFV in the OA and MUA significantly increased from 24 h to 72 h after EB administration on both the ipsi-lateral and contra-lateral sides (p < 0.05); then, their values started to decrease to reach the pretreatment value on day 9 after EB administration. Both E2 and NO concentrations significantly increased (p < 0.05) from 24 h until day 3 after EB injection and then started to decline after that, reaching the pre-treatment value on day 9. In conclusion, the administration of EB enhances the ovarian and uterine blood flow concomitantly with increased levels of NO in PP dairy buffaloes.

Study on Various Luteal Characteristics Using Doppler Ultrasonography for Early Pregnancy Diagnosis in Nili-Ravi Buffaloes

The objective of current study was to assess the trend in various luteal characteristics viz luteal size (LS), plasma progesterone (P⁴) concentration, and luteal blood flow (LBF) using color Doppler imaging (CDI) and power Doppler imaging (PDI) modes in pregnant and nonpregnant Nili-Ravi buffaloes. Lactating, cyclic, and healthy Nili-Ravi buffaloes (n = 09) without any reproductive abnormality were selected in present study. Buffaloes were synchronized using Ov-Synch, and fixed-time artificially insemination was performed (day = 0). Pregnancy was diagnosed on 30-day post-AI using B-mode ultrasonography based on presence or absence of embryonic heartbeat. Ovaries of all animals were scanned from day 5 till 21 post-AI using both B-mode and Doppler ultrasonography to measure LS and LBF. After each ovarian ultrasound examination, blood samples were collected via jugular venipuncture to determine plasma P⁴ concentration. According to results, LBF using CDI and PDI was significantly higher (P ≤ 0.05) in pregnant buffaloes on days 13 and 15 post-AI, respectively. The mean LS and plasma P⁴ concentration did not differ (P ≥ 0.05) between pregnant and nonpregnant animals until day 15 post-AI. However, a significant difference (P ≤ 0.05) was noticed for both on day 17 and onwards. It is concluded that LBF is a more sensitive luteal character as compared to LS and P⁴ for earlier pregnancy diagnosis in Nili-Ravi buffaloes when ascertained through CDI.

Histological and hemodynamic characterization of corpus luteum throughout the luteal phase in pregnant and non-pregnant buffalos in relation to nitric oxide levels based on its anatomical determination

This study aims to compare the complete growth and development of corpus luteum (CL) in domestic buffalos from day 5 until day 40 after ovulation either in pregnant or non-pregnant animals and whether luteal vascularity (LV) with progesterone (P4) and nitric oxide (NO) could determine luteal functionality or not. Pluriparous buffalos (Bubalus bubalis) were categorized as pregnant (n = 6) or non-pregnant (n = 9) after pregnancy check at day 25. Animals were subjected to ultrasound analysis to determine the CL area (cm²) and LV. Blood sampling was performed following the Doppler examination. Ovarian tissue samples from non-pregnant buffalo genitalia (n = 18) and early pregnant buffalo genitalia (n = 3) were collected from great abattoirs. Luteal Doppler indices were lower in the pregnant group, while peak systolic velocity (PSV) was increased (p < 0.05) in the same pregnant females. Both P4 and NOMs were elevated (p < 0.05) in the pregnant group. There was a positive correlation (p < 0.01) between P4 and CL PSV. Based on our macroscopical examination, the CL of non-pregnant buffalos was classified into four stages. Histologically, stage I showed that CL was covered by a highly vascularized connective tissue (CT) capsule. It consisted of small and large lutein cells, whereas stage II was similar to stage I except for the presence of numerous fibroblast cells and vacuolated cells. Stage III was characterized by increasing the number of collagen fibers and the thickness of the blood vessels. Stage IV revealed thickening of the CT capsule and septae, regressed capillaries and arterioles, in addition to shrunken degenerated lutein cells. CL of pregnant buffalos revealed the same structure as CL at stage II. CL area was increased in the pregnant group. The collective data suggested that evaluation of the luteal artery could be extremely helpful to determine the potential benefits of colored and pulsed Doppler in CL vascularization assessment in both luteal and early pregnancy phases.

Ovarian, uterine and luteal hemodynamic variations between pregnant and non-pregnant pluriparous Egyptian buffalos with special reference to their anatomical and histological features

This study determined the ovarian, uterine, and luteal hemodynamic variations using Doppler between pregnant and non-pregnant pluriparous buffalos in relation to their anatomical and histological basics during the first 31 days after natural mating. Adult healthy cyclic Egyptian buffalo (n = 10) were selected and categorized into two groups; group 1 (n = 5) was mated naturally by a fertile bull during the late estrus phase, and group 2 (n = 5) was not mated. Animals were subjected to Doppler ultrasonography to evaluate luteal, ovarian, and uterine blood flows from day 7 until day 31 post-mating. Besides, three pregnant (one month) and other non-pregnant uterus (n = 6) were obtained from a local abattoir to study the anatomical and histological features. Our results revealed that the luteal, ovarian, and uterine arteries cross-sectional diameters/mm increased (P < 0.05) from day 7 till day 31. Resistance (RI) and pulsatility indices (PI) decreased linearly (P < 0.05) in pregnant buffalos till day 31, but the peak systolic, end diastolic velocities and flow volume of those arteries were increased. Additionally, luteal colored areas away and toward CL were increased (P < 0.05) in the pregnant group compared to non-pregnant ones. There was a significant (P < 0.05) increase in the lumen diameter of luteal, ovarian, and uterine artery sections in pregnant buffalos compared to those of non-pregnant ones. While the mean value of tunica media's thickness of both luteal and uterine artery was significantly higher in non-pregnant buffalos than pregnant ones, except for that of the ovarian artery. Additionally, the ovarian and uterine artery tunica muscularis relative area % was (P < 0.05) higher in pregnant buffalos than in non-pregnant ones, except for that of the luteal artery. It was concluded that in pregnant buffalos, ovarian, uterine, and luteal blood flows were improved from the first week until 31 days post-mating via a decline in both Doppler indices with an increase in Doppler velocities and blood flow volume in relation to their histological changes based on their anatomical architecture in comparison to non-pregnant one.

Ultrasonographic findings of the corpus luteum and the gravid uterus during heat stress in dairy cattle

The objectives of this study were to assess alterations in, echogenic appearance, size and blood flow in the corpus luteum, the placentomes and the blood flow in umbilical and uterine arteries that heat stress can cause in cooled pregnant dairy cows. Pregnant cows were allocated in two groups and the gravid uteri, along with the ipsilateral corpora lutea were examined during the winter (group W, n = 9) or the summer (group S, n = 10). The grey-scale ultrasound and colour flow imaging of the corpus luteum and placentome were performed. In addition, the umbilical and uterine artery diameters and haemodynamic parameters in the vessels were calculated. At the time of ultrasonographic examination, cortisol concentrations were higher, and progesterone levels tended to be lower in group S compared to group W. The grey-scale ultrasound evaluation of corpora lutea and placentomes was lower in group S compared to group W. The diameter of umbilical artery and the blood volume in the vessel were less in group S than in group W. We infer that heat stress affects foetal blood supply and possibly the structure of placentomes and corpora lutea, but it differently affects the blood flow characteristics in the umbilical and uterine arteries.

Uterine and Corpus Luteum Blood Flow Evaluation Prior to Uterine Flushing in Llama Embryo Donors

The aim of this study was to assess the uterine blood flow (UBF) and corpus luteum blood flow (CLBF) in llamas 8 days post-mating, using color-Doppler ultrasonography (CDU), to determine the possible relationship between vascularization and the presence of an embryo. Adult females (n = 25) were used to monitor ovarian dynamics by palpation and transrectal ultrasonography until detection of a ≥6 mm growing follicle. Females were randomly assigned to one of two groups: Group I (n = 19), were mated and ovulation was induced by a single dose of buserelin (GnRH analog) that same day (Day 0); and Group II (n = 6), only ovulation was induced (control). On Day 8, UBF and CLBF were evaluated transrectally in both groups. The color-flow images obtained were analyzed with Image J1.52a software to determine the vascularization area and the percentage of corpus luteum with blood flow emission (CLBF%) together with the percentage for each uterine horn (UBF%). Statistical analysis was performed using an ANOVA test. In Group I, uterine flushing was performed to obtain the embryos, thus dividing the females into Group I+ (n = 10), when an embryo was recovered and Group I- (n = 9), when no embryo was recovered. Embryo recovery rate was 52.63% (10/19). In Group I+, UBF% was significantly higher compared to Group I- and Group II (P <0.05). UBF appears to be a good predictor for embryo presence, with an area under the curve (AUC) of 0.9 and an optimal cut-off value of 9.37% (with a sensitivity of 90% and specificity of 88.9%). The CLBF% did not differ between groups (P > 0.05). In conclusion, it is possible to detect a local increase of UBF in the presence of an embryo on day 8 post-mating in llamas. This could be useful to achieve an early pregnancy diagnosis or to decide whether to carry out the uterine flushing in a llama embryo transfer program.

Corpus Luteum Color Doppler Ultrasound and Pregnancy Outcome in Buffalo during the Transitional Period

Simple Summary

The advent of color Doppler ultrasonography promoted tremendous advances in research and clinical practice in animal reproduction, because it allowed noninvasive visualization of the vascularization in reproductive organs. In particular, the corpus luteum blood flow reflects luteal function better than luteal size in ruminants. Since buffaloes are a seasonal species, it is important to evaluate corpus luteum functionality also during the nonbreeding season, through blood flow examination and early pregnancy diagnosis. For this reason, we selected 29 Mediterranean buffaloes that had undergone synchronization and artificial insemination and were examined daily, from 5 to 10 days post-artificial insemination. Then, we retrospectively classified the buffaloes as pregnant or nonpregnant. Statistical analysis showed that pregnant animals had higher mean progesterone concentration and higher mean time average medium velocity values from Day 5 to Day 10 compared to nonpregnant buffaloes. Moreover, these two parameters could be used to predict the likelihood of pregnancy, starting on Day 6, although more reliable results could be obtained at Day 10 post-artificial insemination. In conclusion, a proper CL growth and development from Day 5 to Day 10 post-timed artificial insemination (TAI) is crucial for pregnancy maintenance during the transitional period.

Abstract

This study evaluated corpus luteum (CL) development in buffaloes out of breeding season and assessed an early pregnancy diagnosis. Mediterranean buffaloes (n = 29) were synchronized and artificially inseminated. CL B-mode/color Doppler ultrasonography examinations were performed daily from Days 5 to 10 post-synchronization, recording CL dimensions and blood flow parameters. Blood samples were collected on the same days for the progesterone (P₄) assay. Data were grouped into pregnant or nonpregnant and retrospectively analyzed. The total pregnancy rate was 50.0% (13/26) on Day 45. A significant difference between CL average area in pregnant and nonpregnant buffaloes was recorded only on Day 10. Pregnant buffaloes showed a significantly higher mean P₄ concentration and higher mean time average medium velocity (TAMV) values from Day 5 to Day 10 compared to nonpregnant buffaloes. Linear regression analysis showed a significant relationship between P₄ levels and TAMV. Multiple logistic regression highlighted a significant influence of TAMV on pregnancy outcome, particularly on Day 8. This is probably due to the strong relationship between TAMV and P₄ production. Both TAMV and P₄ could be used to predict pregnancy starting on Day 6, although a more reliable result was obtained at Day 10. Thus, the period between Days 5 and 10 is critical for CL development during the transitional period in buffalo.

Early Prediction of Corpus Luteum Functionality Using an Imaging Software

The present study aimed to assess the applicability of luteal blood flow data acquired through the use of color Doppler ultrasonography and a post-processing analysis tool (ImageJ) for predicting pregnancy in buffaloes (Bubalus bubalis). The experiment was carried out on 59 multiparous Italian Mediterranean buffaloes that underwent synchronization of estrus and fixed-time artificial insemination (TAI). Corpus luteum features (size: CLS and blood flow: BFA) were taken from Day 5 to 10 after TAI and retrospectively measured with ImageJ. In the same period, blood samples were taken to assess progesterone (P₄) concentrations. Pregnancy diagnosis was carried out on Day 45 by ultrasound and confirmed on Day 70 post-TAI. Differences in CLS, BFA, and P₄ concentrations from Day 5 to 10 after TAI measured between groups were analyzed by ANOVA repeated measures as were differences within each day of measuring. Buffaloes that established a pregnancy (n = 29; 55%) had larger CLS (2.2 ± 0.1 vs. 1.9 ± 0.1 cm²; P < 0.01), higher BFA (0.6 ± 0.0 vs. 0.4 ± 0.0 cm²; P < 0.01), and higher P₄ blood level (1.8 ± 0.1 vs. 1.4 ± 0.1; P < 0.01) during Day 5–10 as compared to not-pregnant buffaloes (n = 22). Throughout the entire period, the first feature that changed between groups was P₄ blood concentration at Day 7 (1.7 ± 0.1 vs. 1.2 ± 0.1; P < 0.05) followed by BFA at Day 8 (0.6 ± 0.0 vs. 0.5 ± 0.0; P < 0.05), respectively, in pregnant and not-pregnant animals. The ROC analyses indicated that P₄ was able to predict pregnancy since Day 5 (P < 0.05) although a more reliable result could be obtained from Day 8 (P < 0.01). At Day 10, it was possible to set a cutoff value for every parameter taken into account. The logistic regression analysis showed that pregnancy was positively influenced by P₄ concentration (odds ratio 534.127; P < 0.01) and BFA (odds ratio 744.893; P < 0.01). In conclusion, the use of color Doppler ultrasonography, together with ImageJ, identified different patterns of BFA between pregnant and not-pregnant buffaloes starting from Day 8 post-TAI.

Ovarian follicular changes and hemodynamics in Egyptian buffaloes under CIDR-PGF2α and Ovsynch-CIDR estrus synchronization treatments

This study aimed at investigating the efficacy of two protocols of estrous synchronization on follicular changes and hemodynamics. Pluriparous Egyptian buffaloes (n = 36) were synchronized either with controlled internal drug release (CIDR)-PGF2α (7-days CIDR insert with PGF2α injected on the 6^th day; n = 18) or Ovsynch-CIDR (Ovsynch protocol concurrent with 7-days CIDR insert; n = 18). Blood sampling and ovarian ultrasound examinations (Grayscale, color and power Doppler modes) were conducted on the Day of CIDR removal, estrus, and luteal phase. Mean follicle diameter (MFD), first (1^st-LF) and second (2^nd-LF) largest follicle diameters, and E2 levels significantly increased in the CIDR-PGF2α group at CIDR withdrawal. Ovsynch-CIDR markedly fortified higher follicle population, MFD, and 1^st-LF diameter at estrus and corpus luteum (CL) volume at the luteal phase in concomitant with increases (P < 0.05) in E2 (at estrus) and P4 (at luteal phase). At CIDR removal, the blue pixels in the dominant follicle (DF) were higher (1.5 times; P = 0.054) in the Ovsynch-CIDR than in the CIDR-PGF2α. At estrus, total blood flow (TBF) and power Doppler pixels (PDP) to DF(s) were noticeably higher (seven and 1.6 times; respectively) in the Ovsynch-CIDR than in CIDR-PGF2α (5906 ± 237 vs. 830 ± 60 pixels, P < 0.01 and 5479 ± 322 vs. 3377 ± 19 pixels, P < 0.05; respectively). At the luteal phase, TBF and PDP to the CL increased in the Ovsynch-CIDR group than in the CIDR-PGF2α group (11060 ± 965 vs. 7963 ± 480 pixels, 1.4 times, P = 0.05 and 18900 ± 1350 vs. 13220 ± 568 pixels, 1.1 times, P = 0.005; respectively). In conclusion, based on the improvement in synchronized follicular activity and hemodynamics, the Ovsynch-CIDR regimen is persuaded in Egyptian buffaloes.

Accuracy of subjective evaluation of luteal blood flow by color Doppler ultrasonography for early diagnosis of pregnancy in Egyptian buffalo

The objective of the current study was to evaluate the accuracy of trans-rectal color Doppler ultrasonography for early diagnosis of pregnancy in Egyptian buffalo based on subjective assessment of luteal blood flow (LBF). After timed artificial insemination (TAI), a total of 112 pluriparous buffalo were subjectively evaluated for LBF and there were score scales or grades (I-IV) determined at different times (Days 6, 14, 17, 21) post-TAI. Another trans-rectal B-mode ultrasonography of the uterus was performed at Day 35 to confirm pregnancy diagnosis based on recognition of the positive signs of pregnancy. Retrospectively, the results of B-mode ultrasonography were compared to that of the subjective evaluations of LBF for determining accuracy values. Furthermore, serum progesterone (P4) concentrations were determined as an indicator of corpora lutea (CL) function. Results indicate 68 of 112 buffalo (60.7%) were diagnosed as pregnant. The accuracy value of the LBF subjective evaluation was significant (80.4%; P <  0.05) at Day 17, and there was the maximum accuracy (96.4%) at Day 21 post-TAI. The percentage of false diagnoses was less at Days 17 and 21 compared with Day 6 and 14 post-TAI. There was a significant matching value between P4 concentrations and scores for LBF on and after Day 17 post-insemination. In conclusion, subjective evaluation of LBF using color Doppler ultrasonography is considered an accurate technique for early detection of pregnancy in Egyptian buffalo especially the non-pregnant animals as early as Day 17, with maximum accuracy at Day 21 post-TAI.

Vascular and morphological features of the corpus luteum 12 to 20 days after timed artificial insemination in dairy cattle

Our objective was to retrospectively compare pregnant versus nonpregnant cattle in terms of vascular and morphometric changes in corpora lutea between d 12 and 20 following timed artificial insemination (TAI). Crossbred (Gir × Holstein) lactating dairy cows (n = 136) and heifers (n = 111) were bred after synchronizing ovulations using an estradiol plus progesterone (P4)-based protocol. Corpus luteum (CL) characteristics (area, echotexture, blood flow) were recorded at 48-h intervals from d 12 to 20 following TAI using an ultrasound equipped with color Doppler. Blood samples were collected to determine CL function (plasma P4). Pregnancy diagnosis was performed at d 30. Quantitative assessment of colored pixels within the CL was performed using ImageJ software (National Institutes of Health, Bethesda, MD) and echotexture was quantified using custom software. Continuous variables such as luteal tissue area (LTA), CL blood flow (CLBF), adjusted CLBF (ratio LTA:CLBF), mean pixel value (MPV), pixel heterogeneity (HETER), and plasma P4 were analyzed retrospectively as repeated measures (d 12 to 20) in pregnant versus nonpregnant females using PROC MIXED (SAS Institute Inc., Cary, NC). Main effects were pregnancy status, day of cycle, and their interaction. Further analyses used only data from d 16, because this was the earliest time point of deviation between CLBF of pregnant and nonpregnant animals. We created quartiles for each variable and calculated the risk of pregnancy within quartile. Differences were determined using the chi-squared test. Plasma P4 was significantly higher in prospective pregnant versus nonpregnant cattle on d 18 and 20, whereas LTA differed only on d 20. On d 16, CLBF and adjusted CLBF diverged between pregnant and nonpregnant, followed by a progressive reduction in the latter until d 20. Mean pixel value was not affected by pregnancy status, but HETER was lower on d 20 in pregnant than in nonpregnant cattle. Likelihood of pregnancy increased from quartile (Q)1 (lowest values) to Q4 (highest) of CLBF (Q4 vs. Q1, odds ratio = 32.8, 95% confidence interval: 9.6 to 112.1) and adjusted CLBF [Q4 vs. Q1, odds ratio = 25.4, 95% confidence interval: 8.1 to 80.4), whereas a lower risk of pregnancy was observed only for animals within Q1 of plasma P4 [Q4 vs. Q1, odds ratio = 3.1, 95% confidence interval: 1.3 to 7.2). Day 16 quartiles of LTA, MPV, and HETER did not affect odds of pregnancy. In conclusion, we identified distinct CLBF patterns as early as 16 d after TAI and confirmed that CL function is lost by a reduction in blood flow, which precedes physical regression.

Dynamics of uterine and ovarian arteries flow velocity waveforms and their relation to follicular and luteal growth and blood flow vascularization during the estrous cycle in Friesian cows

Doppler ultrasonography enabled understanding of the reproductive system hemodynamics in cyclic and pregnant cattle. To confirm the hypothesis that the ipsilateral ovarian and uterine arterial blood flows to the ovulating ovary are higher than the contralateral one along days and phases (follicular, early luteal, mid-luteal, late luteal) of the estrous cycle, eight cyclic spontaneously ovulating cows were scanned with Doppler ultrasound each other day along three oestrous cycles to monitor the follicular dynamics, the vascularization of the ovulatory follicle (OF), the corpus luteum (CL) developmental dynamics, the ipsilateral and the contralateral ovarian and uterine arterial diameters and their blood flow. Results proved the hypothesis. Both days and phases of the estrus cycle influenced (P = 0.0001) the follicular dynamic, the luteal hemodynamics, the ovarian and uterine hemodynamic. The ovulatory wave and the mid-luteal non-ovulatory wave had expanding numbers and the diameters of small, medium and large follicles. Though area, antral area, vascularization area of the OF ascended from Day -4 to the day of ovulation (Day 0), but the percent of its vascularization area and that of granulose layer increased till Day -3. The CL diameter increase till Day 15, and its vascularization area increased till Day 13, but its% of vascularization area ascended (P = 0.0001) from Days 1-4 and declined from Days 9-13. Both RI and PI of the ipsilateral ovarian artery were lower than the contralateral one; but, both obtained high values during the follicular phase. A linear increase (P = 0.0001) of uterine horns vascularization area and both ovarian and uterine arteries diameters, PSV and EDV from follicular to late luteal phases accompanied a linear decrease of their PI and RI. In conclusion, the ovarian and uterine blood flows vary according to the estrous day, estrous phase, the ovulating ovary, ovulatory follicle growth and corpus luteum developmental stage.