Reproduction in Domestic Animals最新文献

Oxidative stress-induced granulosa cells (GCs) apoptosis is believed to be the hallmark of follicular atresia. Although a large number of studies have shown that some molecules in follicular fluid (FF) are important to granulosa cell survival, the key substances in FF associated with the regulation of granulosa cell apoptosis have not been fully elucidated. Herein, metabolomics analysis showed that the glutamine level in healthy FF was significantly higher than that in atretic FF. Then, an oxidative stress model was built up by adding hydrogen peroxide (H₂O₂). The results revealed that treating porcine GCs with H₂O₂ significantly elevated the reactive oxygen species (ROS) levels (p < 0.01) and caused a marked decrease in cell viability (p < 0.0001). Exogenous glutamine alleviated the intracellular ROS accumulation and porcine GCs apoptosis induced by H₂O₂ (p < 0.05). Knocking down glutamine synthetase (GLUL), the key gene for glutamine synthesis, diminished cell viability (p < 0.01) and increased intracellular ROS levels and porcine GCs apoptosis (p < 0.05). Both H₂O₂ and the knockdown of GLUL activated the JNK signalling pathway, while glutamine decreased the activation of JNK to protect porcine GCs from oxidative stress-induced apoptosis. These findings indicate that glutamine protects porcine GCs from oxidative stress-induced apoptosis by inhibiting JNK activation, which is of great significance for clarifying the molecular mechanisms behind follicular atresia.

The aim of this study was to describe and compare the effect of different lighting protocols on sexual cyclicity and serum melatonin in domestic female cats. Additionally, anti-Müllerian hormone (AMH) concentrations and ultrasound or histological imaging of the ovaries were included. For this purpose, three experiments (Expt.) were conducted under controlled lighting conditions: Expt. I: A short photoperiod (SP) vs. a long photoperiod (LP), Expt. II: LP preceded by a SP, and Expt. III: Prolonged 6-month SP. In both Expt. I and II LP increased most of the ovarian functionality parameters, prior exposure to a SP did not increase functionality. In Expt. I, AMH serum concentrations did not differ between both photoperiods. In Expt. II, ultrasound ovarian volume and follicle diameters were larger in LP than in SP. Intraovarian arteries' resistance index was lower in LP. In Expt. III, cyclicity was maintained without quantitative differences between the first and the second half. At the end of Expt. III, the ovaries presented a proportion of 92.08% primordial, 2.35% primary, 2.26% secondary, and 3.31% small antral follicles. Corpora lutea also appeared in three queens. In the three experiments, spontaneous ovulation frequency was not influenced by the photoperiod. In both Expt. I and II, serum melatonin concentrations were not different between photoperiods. These concentrations did not also differ at the end of Expt. III. It was concluded that although sexual activity was more intense under this artificial LP, independently of the previous photoperiod, cyclicity and ovulation were maintained under a SP.

The aims of this study were to assess the effects of resveratrol-loaded nanoparticles (RLNP) on follicular survival, stromal integrity and activity of endogenous free-radical scavengers in bovine ovarian tissues cultured in vitro. Ovarian cortical slices were incubated in α-MEM⁺ alone or supplemented with 0.2, 2.0 or 20.0 μM RLNP, blank nanoparticles (BNP) or free resveratrol (20.0 μM) for 6 days at 38.5°C and 5% CO₂. Follicular integrity, number of stromal cells, density of collagen fibres, levels of thiol and activity of free-radical scavengers (glutathione peroxidase [GPX], superoxide dismutase [SOD] and catalase [CAT]) were evaluated in tissues cultured in the different treatments. The data showed that ovarian cortex cultured with 20.0 μM free resveratrol or RLNP, in all tested concentrations, had a reduced rate of morphologically intact follicles in relation to uncultured controls (p < 0.05). The RLNP (0.2, 2.0 or 20.0 μM) and BNP increased the proportion of growing follicles and stromal cell numbers (p < 0.05). Collagen fibre levels decreased in tissues cultured with 0.2 or 2.0 μM RLNP compared to uncultured controls, but remained greater than those seen in ovarian cortex cultured in other treatments (p < 0.05). Free resveratrol increased CAT and GPX activity, while RLNP reduced activity of SOD and GPX (p < 0.05). In conclusion, RLNP improved follicle survival and growth, preserved stromal tissue and modulated the activity of free-radical scavengers in bovine ovarian slices cultured in vitro.

The study evaluated the effects of denaverine hydrochloride (DH) and carbetocin (CT) on calving ease and subsequent fertility in suckler cows. A total of 242 cows were enrolled in a blinded study and assigned to four groups with different treatment protocols: Group A (DH + CT), Group B (DH only), Group C (CT only) and Group D (saline only-control). After the second round of exclusion criteria, 225 animals were allocated into 4 groups A (n = 69), B (n = 59), C (n = 60), D (n = 37) for the further statistical analysis. DH was given (Groups A and B) within 30 min after the noticed appearance of the amniotic sac. Carbetocin was given (Groups A and C) within 30 min of the calf expulsion. Five parameters were analysed: time from appearance of amniotic sac to calf expulsion (Time to expulsion, TTE), incidence of foetal membranes retention (RFM), calf mortality (calves dead within 48 h, CM), number of artificial inseminations until pregnancy (nAI), and days open (DO). Group A exhibited significantly shorter TTE compared to Groups C (p = 0.02) and D (p < 0.001), indicating improved calving performance and reproductive efficiency. Group A also required less nAI compared to Group D (p = 0.01). While no significant differences in TTE or nAI were observed between Groups A and B. Group A had significantly fewer DO compared to Groups C (p = 0.04) and D (p = 0.003), suggesting a potential synergistic benefit of DH and CT. Carbetocin, when administered alone, showed no significant effects on the observed parameters. RFM and CM incidence did not significantly differ across groups. These findings support the beneficial role of DH, particularly when combined with CT, in facilitating parturition, improving welfare and enhancing subsequent fertility.

Impotentia generandi (IG) is a significant infertility problem in male camels. The objective of this research was to investigate the histopathological changes, DNA damage and inflammatory cytokine expression of interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), as well as the proapoptotic protein Bcl-2-associated X-protein (BAX), in testicular degeneration (TD) in IG male camels and their association with clinical findings and semen characteristics. The study included 15 male camels with IG (IG group) and 15 fertile camels (FERT group). Semen collection and evaluation were performed on the epididymal sperm of all selected males. Blood samples for testosterone (T) evaluation and tissue samples for histological investigation were collected. Histo-fluorescent staining was used to investigate DNA damage, and immunohistochemical investigations of TNF-α, IL-6 and BAX proteins were conducted on testicular tissue. Results showed that testosterone concentrations were significantly lower in the IG group compared to the FERT group. Additionally, significant differences were observed in sperm motility, viability and concentration between the two groups. Histological examination revealed atrophy of the seminiferous tubules (STs), disruption and disorganisation of the germinal epithelium and a significant decrease in epithelial thickness and ST diameter. Histochemical inspection showed high fibrosis and severe DNA damage. Furthermore, significant positive reactions to IL-6, TNF-α and BAX proteins were observed in the testicular tissue of the IG group compared to the FERT group. In conclusion, IG in male dromedary camels manifests as TD, initiated by DNA damage and upregulated expression of IL-6, TNF-α and BAX proteins in the testicular tissue.

Reproductive efficiency and female fertility are crucial for productive and sustainable reproductive outcomes in buffalo. Endotoxin lipopolysaccharide (LPS) produced by Gram-negative bacteria initiates a series of inflammatory cascade events which affect ovarian steroid production, impact oocyte and ultimately hamper the developmental competence of the embryo. The objective of the current study was designed taking endometritis as an in vitro model to elucidate the molecular pathway through which LPS affects embryo competence. To achieve this objective, buffalo ovaries were procured from a nearby slaughterhouse and oocytes were aspirated via the follicular aspiration method with an 18-gauge needle fitted with a 10 mL syringe. After searching and washing, good quality (A and B grade) oocytes were subjected to IVM, IVF and subsequently IVC, with media supplemented with 5 μg/mL of LPS based on previous laboratory standardisation. Our results demonstrate that LPS exposure reduced cleavage rate, blastocyst formation rate, total cell count, mitochondrial membrane potential (MMP), trophectoderm: inner cell mass (TE: ICM) ratio while significantly (p < 0.05) increasing reactive oxygen species (ROS) levels and apoptotic rate in blastocysts. Furthermore, LPS exposure significantly (p < 0.05) upregulated the relative mRNA expression of inflammatory (TLR4, CD14, RPS27A) and apoptotic gene (Caspase 3) whereas it downregulated the expression of antioxidant (GPX1) and pluripotent gene (Oct4) in blastocysts. Based on these findings, we concluded that although a concentration of 5 μg/mL LPS is minimally harmful to the oocytes, its presence during IVC adversely affects embryonic development.

Altrenogest is widely used for synchronising gilt breeding groups. On-farm constraints often require adjusting supplementation duration depending on cycle monitoring and batch intervals; however, the reproductive impact of these shorter regimens remains unclear. This retrospective study evaluated the reproductive performance of gilts treated with Altrenogest for different durations in a batch farrowing breeding herd. Gilts (~166 days old at arrival) that exhibited their first estrus within 40 days post-arrival were allocated to three treatments: ALT 6-14 (n = 166), receiving Altrenogest for 6-14 days; ALT 15-21 (n = 190), receiving Altrenogest for 15-21 days and Control, receiving no treatment (n = 175). Altrenogest supplementation started on days 11-12 after their last estrus (first or second). Insemination for ALT gilts was performed at the first estrus following treatment (~231 days old). For Control gilts, insemination occurred in the third or fourth estrus (~230 days old). Approximately 98% of the ALT gilts exhibited estrus, whereas 10.3% of the Control gilts did not display estrous signs within the breeding window. The interval from the end of the Altrenogest treatment to estrus expression was slightly longer (p = 0.05) in ALT 15-21 (6.6 ± 0.2 days) than in ALT 6-14 (6.4 ± 0.2 days). Adjusted farrowing rate and total litter size did not differ among treatments (p ≥ 0.69). The duration of Altrenogest supplementation did not affect estrous cycle synchronisation efficiency or the reproductive performance of gilts. The strategic use of Altrenogest enables a reduction in labour and costs by allowing progestogen supplementation for fewer than 14 days.

Differences in clinicochemical serum parameters of gestating Bos taurus taurus (taurine, Angus) and Bos taurus indicus (indicine, Brahman) cattle and the relationships of such parameters with conceptus phenotype are largely unexplored. We determined the concentrations of 21 electrolytes, metabolites and enzymes in serum of Angus and Brahman dams at early (Day 48, n = 24) and midgestation (Day 153, n = 37) and examined relationships with embryo, fetal and placental weights. At early gestation, ionised calcium (+26%), magnesium (+7%), lactate (+32%), total protein (+6%) and alanine transaminase (ALT, +39%) were significantly (p < 0.05) higher in Angus than in Brahman. At midgestation, ionised (+15%) and total calcium (+4%), magnesium (+11%), sodium (+2%), calcium/phosphorus ratio (+25%) and albumin (+5%) were higher (p < 0.05) in Angus cows. Ionised calcium, magnesium, sodium, albumin, lactate and ALT correlated positively with embryo, fetal and/or placental weights (r = 0.31-0.48, p < 0.05), while calcium/phosphorus ratio correlated negatively with Day 48 placental weight (r = -0.51, p < 0.05). Serum creatinine (+21%), glucose (+15%), triglycerides (+16%), alkaline phosphatase (ALP, +73%) and glutamate dehydrogenase (GLDH, +44%) levels were higher (p < 0.05) in Brahman at midgestation. Creatinine, glucose and ALP correlated negatively with fetal and placental weights at midgestation (r = -0.37 to -0.48, p < 0.05-0.01). Our data demonstrate genetic effects on maternal blood composition that reflect differences in maternal physiology of gestating taurine and indicine cattle which may affect conceptus growth and birthweight.

In vitro maturation (IVM) of oocytes is crucial in livestock breeding. Oocytes obtained by IVM are more susceptible to oxidative stress than in vivo, leading to low maturation rates. Betaine from red beetroot acts as an antioxidant and methyl donor, regulating epigenetic modifications in cell physiology. This study investigates Betaine's effects on porcine oocyte IVM, embryo development and underlying molecular mechanisms. Results demonstrate that 16 mmol/L Betaine significantly enhances the first polar body extrusion, cleavage and blastocyst rates compared to the control and other concentrations. Betaine elevates normal cortical granule distribution, normal spindle assembly, normal chromosome arrangement and overall m6A levels during IVM. It increases the antioxidant gene expression and mitochondrial function and decreases reactive oxygen species levels. However, Betaine's beneficial effects were diminished by AMPK inhibitor compound C. In conclusion, Betaine enhances porcine oocyte IVM and early embryo development by enhancing the antioxidant capacity and mitochondrial function pathway.

This study aims to investigate the cryoprotective effect of Omega-3 nano-emulsion (Omega-3 NE) on stallion sperm quality, kinematic parameters, acrosome status, subcellular ultrastructure, oxidative/antioxidant markers, and semen microbiota. Forty ejaculates were collected, extended, and cryopreserved from 5 fertile Pure Egyptian stallions (Equus caballus). The ejaculates were divided into five groups: a control group (without additive) and four groups supplemented with 25, 50, 100, and 200 μg of Omega-3 NE/mL. The Omega-3 NE exhibited an average particle size of 51-146 nm, a PDI of 0.58, and a zeta potential of -31 mV. Omega-3 NE (200 μg/mL) significantly improved progressive motility, viability, and membrane integrity of stallion semen (p < 0.05). Additionally, supplementation with Omega-3 NE (200 μg/mL) led to a significant enhancement in post-thawed sperm kinematic parameters, including PM, DSL, VCL, and VSL, by 40%, 21.5%, 26.7%, and 20.7%, respectively, compared to the control group. The addition of 100 or 200 μg/mL Omega-3 NE to the media resulted in a higher percentage of live sperm with intact acrosomes. Additionally, all Omega-3 NE treatments significantly decreased the percentage of dead sperm with intact acrosomes as well as microbiota load (total bacterial count and coliform bacteria count) compared to the control (p < 0.01). Significant improvements in antioxidant status (TAC and CAT) and reduction of oxidative stress markers (MDA, NO, and H₂O₂) were observed in all Omega-3 NE groups compared to the control group (p < 0.05). Omega-3 NE (200 μg/mL) significantly reduced sperm apoptosis (p < 0.01) and preserved better subcellular integrity compared to the control and other treatment groups. The results suggest that Omega-3 NE at concentrations of 100-200 μg/mL can effectively enhance sperm cryo-resistance via enhancing sperm quality and kinematic variables, reducing oxidative stress and microbiota load, and maintaining sperm subcellular ultrastructure. The study highlights the potential of Omega-3 NE as a nanotechnology-based approach to boost assisted reproductive technologies in stallion breeding programmes.