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This study was aimed to investigate the combined effect of zinc sulphate and folic acid (ZnF) dietary supplementation on testicular haemodynamics (TH), testicular volume (TV), plasma testosterone levels (T) and semen quality of rams under heat stress conditions. Fifteen Ossimi rams were allocated to three groups: (1) G0 (n = 5) received only basic diet; (2) G1 (n = 5) received basic diet +ZnF (Zn, 0.4 mg/kg bw; F, 0.02 mg/kg bw) and (3) G2 (n = 5) received basic diet +ZnF (Zn, 0.8 mg/kg bw; F, 0.04 mg/kg bw) daily for 60 days. TH was evaluated using colour (testicular coloration, TC) and spectral modes [resistive index (RI) and pulsatility index (PI)] Doppler of the supra‐testicular arteries (proximal and distal parts, STA). Semen traits including progressive motility (PM), alive sperm % (AS), sperm viability (SV), sperm abnormalities (SA) and acrosome integrity (AI) were also assessed. The examinations were carried out one month before (D‐30), the beginning of ZnF inclusion in the diet (D 0) and continued for the successive two months (D 30 and D 60). TH was significantly (p < .05) improved at D 30 and D 60, evidenced by lowering both RI and PI and increasing of TC in G1 compared to G0 and G2. In addition, both TV and serum T levels were elevated (p < .05) at D 30 and D 60 in G1 compared to other groups. Semen quality parameters (PM, AS, SV and AI) were significantly (p < .05) augmented in the same trend as TH, TV and T in G1 versus G0 and G2. A marked decrease (p < .05) in SA % was noticed at Days 30 and 60 after ZnF inclusion in G1 compared to G0 and G2. In conclusion, supplementation of the summer diet with ZnF improved the whole reproductive functions such as testicular haemodynamics and semen quality of rams housed in heat stress conditions.

Fifteen cyclic, multiparous goats were equally stratified and received the common Ovsynch protocol (GPG: intramuscular, IM, injection of 50 mg gonadorelin, followed by an IM injection of 125 µg cloprostenol 7 days later, and a further IM injection of 50 mg gonadorelin 2 days later) or the Ovsynch protocol using nanofabricated hormones with the same dosages (NGPG) or half dosages (HNGPG) of each hormone. The ovarian structures and ovarian and luteal artery hemodynamic indices after each injection of the Ovsynch protocol using B-mode, color, and spectral Doppler scanning were monitored. Levels of blood serum progesterone (P4), estradiol (E2), and nitric oxide (NO) were determined. After the first gonadotrophin-releasing hormone (GnRH) injection, the number of large follicles decreased (p = 0.02) in NGPG and HNGPG, compared with GPG. HNGPG resulted in larger corpus luteum (CL) diameters (p = 0.001), and improved ovarian and luteal blood flow, compared with GPG and NGPG. Both NGPG and HNGPG significantly increased E2 and NO levels compared with GPG. HNGPG increased (p < 0.001) P4 levels compared with GPG, whereas NGPG resulted in an intermediate value. After prostaglandin F2α (PGF2α) injection, HNGPG had the largest diameter of CLs (p = 0.001) and significantly improved ovarian blood flow compared with GPG and NGPG. Both NGPG and HNGPG increased (p = 0.007) NO levels, compared with GPG. E2 level was increased (p = 0.028) in HNGPG, compared with GPG, whereas NGPG resulted in an intermediate value. During the follicular phase, HNGPG increased (p = 0.043) the number of medium follicles, shortened (p = 0.04) the interval to ovulation, and increased (p < 0.001) ovarian artery blood flow and levels (p < 0.001) of blood serum P4, E2, and NO, compared with GPG and NGPG. During the luteal phase, the numbers of CLs were similar among different experimental groups, whereas the diameter of CLs, luteal blood flow, and levels of blood serum P4 and NO increased (p < 0.001) in HNGPG, compared with GPG and NGPG. Conclusively, the nanodelivery system for the Ovsynch protocol could be recommended as a new strategy for improving estrous synchronization outcomes of goats while enabling lower hormone dose administration.

Heat stress (HS) diminishes the testicular antioxidant defense systems, which adversely affect the testicular blood perfusion. Improving the testicular hemodynamics during HS conditions is of a great impact on the whole reproductive performance in rams. This study aimed to evaluate the ameliorative effects of L-carnitine (LC) on the testicular blood flow and echotextures and also on the total antioxidants (TAC) and nitric oxide (NO) concentrations in the serum during HS conditions in rams. Testicular blood flow was evaluated through scanning of the supra-testicular artery (STA) spectral patterns through pulsed Doppler ultrasonography [peak systolic velocity (PSV), end-diastolic velocity (EDV), time average maximum velocity (TAMAX), resistive index (RI), and pulsatility index (PI)], while the echotexture assessment of testicular parenchyma was performed by a computerized software program. Moreover, TAC and NO concentrations were assayed colorimetrically using the spectrophotometer. There were significant decreases (P &lt; 0.05) in values of PSV at 48 and 168 h (23.45 ± 0.39 and 23.37 ± 1.41 cm/s, respectively), and TAMAX at 1, 48, and 168 h (17.65 ± 0.95, 17.5 ± 0.13, and 16.9 ± 1.05 cm/s, respectively) after LC administration compared to just before administration (31.92 ± 1.13 and 21.58 ± 0.92 cm/s, respectively). Values of RI and PI of the examined STA significantly decreased, especially at 1 h for RI (0.45 ± 0.02) and 1 and 48 h for PI (0.66 ± 0.06 and 0.65 ± 0.05, respectively) after LC treatment to 0 h (0.55 ± 0.03 and 0.84 ± 0.06, respectively). The EDV values did not show any significant (P &lt; 0.05) changes in all the experimental time points. There were significant (P &lt; 0.05) increases in the values of pixel intensity of the testicular parenchyma, especially at 1 and 168 h (78.71 ± 2.50 and 88.56 ± 4.10, respectively) after LC administration, compared to just before administration (69.40 ± 4.75). Serum NO levels tend to increase after LC administration (P = 0.07) concerning just before administration. While TAC values showed significant gradual increase and reached the highest values at 168 h (2.75 ± 0.58 mM/l) after LC administration, compared to 0 h (1.12 ± 0.05 mM/l). In conclusion, exogenous LC administration ameliorates testicular hemodynamic disruptions, as measured by spectral Doppler ultrasonography, via augmentation of the rams' total antioxidant capacity under HS conditions.

Heat stress (HS) during pregnancy adversely affects uterine vascular perfusion and foetal development. L‐arginine (L‐Arg), a nitric oxide (NO) precursor, has been proven to enhance an organ's vascular perfusion. Therefore, this study aimed to examine the effect of L‐Arg administration on the pregnant buffaloes' uterine haemodynamics and uteroplacental thickness under environmental HS conditions. For this purpose, pluriparous (n = 12) HS‐pregnant buffaloes (mid‐gestation, 180–190 days; temperature humidity index >85) were haphazardly assigned into two groups, either administered a single intravenous (IV) bolus of 5 mg/kg BW of L‐Arg Hcl (n = 6; ARG) or received normal saline (0.9%; IV; 25 ml) that served as a control group (n = 6; CON). Combined uteroplacental thickness (CUPT, mm), middle uterine arteries' (MUA) diameter (mm) and uterine Doppler haemodynamics (ipsilateral and contralateral to the pregnant horn) were examined utilizing B‐mode and colour Doppler ultrasonography, respectively. The serum levels of progesterone (P4), estradiol 17β (E2), nitric oxide (NO) and total antioxidant capacity (TAC) were assayed using commercial kits. The experimental time points were − 1, 0, 2, 4, 24, 48, 72, 96 and 120 h post‐L‐Arg administration. The ARG group showed higher (p < .05) CUPT and MUA diameter values starting at 24 h post‐treatment and onward than the control buffalo cows. In addition, there were improvements (p < .05) in the blood flow parameters in the ipsilateral MUA after L‐Arg treatment evidenced by lower values of pulsatility and resistive indices starting at 48 and 4 h, respectively and onward, and higher values of peak systolic velocity, coloured areas towards the pregnant uterine horn (both 24–72 h). Increases in the NO levels were found during the period between 4 and 120 h in the ARG group compared to the CON group. Moreover, significant increases in the E2 and P4 means were noted in the ARG group, especially at 24 h onward, respectively compared to the CON group. Concerning the TAC status, neither the administration nor the hours affected serum TAC levels in the HS pregnant buffaloes (CON and ARG). In conclusion, L‐Arg administration improved uteroplacental thickness and enhanced uterine haemodynamics, NO levels, and steroids production in mid‐pregnant buffalo cows under environmental heat stress conditions which could improve foetal growth and development.

Understanding the does reproductive hemodynamic changes during the estrous cycle is crucial for improving reproductive competence and fertility potential in this species. The objective of this study is to investigate the hemodynamic variations in ovarian (OA) and uterine (UA) arteries, histological and morphometric changes in ovarian and uterine tissues throughout the follicular (FP) and luteal (LP) phases in rabbits and determine estrogen (ER), progesterone (PR) receptors, and vascular endothelial growth factor (VEGF) distributions using immunohistochemistry.Fourteen adults pluriparous New Zealand rabbits were divided into rabbits at the FP (Day − 1; n = 7) and those at the LP (Day 9; n = 7). Animals were subjected to Doppler, hormonal (estrogen [E2], progesterone [P4], insulin-like growth factor [ILGF], and VEGF), histological, and immunohistochemical analyses. In LP, OA Doppler indices were significantly increased, whereas peak systolic velocity (PSV) was decreased compared with that in FP. UA Doppler indices were significantly decreased in the LP, whereas PSV was increased (P < 0.05). E2 levels were increased in the FP, whereas P4 levels were increased in the LP. The morphometric analysis of uterine tissues during the LP revealed an increase in the mean uterine endometrium length, endometrial connective tissue area percentage (%), endometrial glands number, myometrial area (%) and thickness. Furthermore, ovarian follicles and corpus luteum (CL) displayed strong positive immunoreactivity for ER, PR, and VEGF-A during both phases. The ovarian sections displayed a substantial (P < 0.05) increase in the area % of VEGF-A in the ovarian follicles during FP while in the CL during LP. Conversely, area percentage of VEGF-A immunoreactivity in the uterine luminal and glandular epithelia during the FP and LP revealed no differences. However, the number of VEGF-A–stained blood capillaries revealed an increase during LP than FP. In conclusion, this study demonstrated for the first time the changes in both ovarian and uterine arteries during two different phases of the rabbit cycle in relation to the histo-morphometric analysis and distribution of ER, PR, and VEGF-A, which regulate uterine functions that play a role in reproduction.

The current study aimed to assess the ovarian and uterine haemodynamics in postpartum (pp) Egyptian buffaloes and their relation to steroid hormonal levels (progesterone and estrogen). Six multiparous buffalos with normal calving were examined by using trans-rectal Doppler sonography to assess the blood flow in ipsilateral and contralateral ovarian and uterine arteries. Doppler parameters viz. peak systolic velocity (PSV), blood flow volume (BFV), resistance (RI) and pulsatility index (PI) were measured at 1st till 6th postpartum weeks. In addition, diameters (mm) of the ovarian and uterine arteries and the vascularisation area (mm2) of ovary were determined. The blood samples were collected starting from 1st week post calving and every week thereafter following each ultrasound Doppler examination for assay of progesterone and estradiol. Results indicated that PI and RI increased consistently and significantly (P<0.05) till the 6th week post calving as compared to those recorded at 1st week in ipsilateral ovarian and uterine arteries. However, the blood flow volume and peak systolic velocity in both ovarian and uterine arteries decreased gradually from 1st week till the 6th week after calving. There were very strong positive correlations between PSV and BFV, in both ipsilateral and contralateral ovarian and uterine arteries. Blood concentrations of progesterone were lower (P<0.05) during the first four weeks than those recorded at 5th and 6th postpartum weeks. This trend was reversed for blood estradiol 17-β. The results of the present investigation concluded that Doppler ultrasonography is a suitable tool for assessing changes in ovarian and uterine perfusion during the puerperium.