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<jats:title>Abstract</jats:title><jats:p>Sterilization of the culture medium using ultraviolet (UV)‐C reduces the potential adverse effects of microorganisms and allows for long‐term use. In the present study, we investigated the effects of a medium directly irradiated with UV‐C prior to in vitro culture on the development and quality of porcine in vitro‐fertilized embryos and the free amino acid composition of the culture media. The culture media (porcine zygote medium [PZM‐5] and porcine blastocyst medium [PBM]) were irradiated with UV‐C at 228 and 260 nm for 1 and 3 days, respectively. Next, the culture media were irradiated with UV‐C at 228 nm for 3, 7, or 14 days. After in vitro fertilization, the embryos were cultured in the UV‐C‐irradiated media for 7 days. Free amino acid levels in culture media irradiated with 228 and 260 nm UV‐C for 3 days were analysed. The blastocyst formation rate of embryos cultured in media irradiated with 260 nm UV‐C for 3 days was significantly lower than that of embryos cultured in non‐irradiated control media. However, 228 nm UV‐C irradiation for up to 14 days did not affect blastocyst formation rates and quality in the resulting blastocysts. Moreover, 260 nm UV‐C irradiation significantly increased the taurine concentration in both culture media and decreased methionine concentration in the PBM. In conclusion, UV‐C irradiation at 228 nm before in vitro culture had no detrimental effects on embryonic development. However, 260 nm UV‐C irradiation decreased embryo development and altered the composition of free amino acids in the medium.</jats:p>

<jats:title>Abstract</jats:title><jats:p>For maximum productivity in a dairy farm, the earliest and the most accurate detection of pregnancy is essential. The aim of this study was to determine the efficacy of expression patterns of miR‐26a, and serum Preimplantation Factor (PIF) levels for pregnancy diagnosis during the early pregnancy in nulliparous and multiparous cows. A total of 60 cows (30 nulliparous and 30 multiparous Holstein cows) were enrolled in the study. Blood samples were collected for miR‐26a on days 8 and 16 (D8 and D16), and for the PIF on days 10 and 20 (D10 and D20) following insemination (D0). Pregnancies were determined by ultrasonography on the 28th day after insemination. Expression levels of miR‐26a determined by qPCR. PIF levels were assessed by using commercial ELISA kits. All data were analyzed by using the MIXED procedure of SPSS. The expression levels of miR‐26a were 6.64 folds higher on D16 in pregnant compared to non‐pregnant multiparous cows (<jats:italic>p</jats:italic> &lt; .05). On D8 and D16, miR‐26a expression levels were found higher 13 folds in pregnant compared to non‐pregnant nulliparous cows (<jats:italic>p</jats:italic> &lt; .05). Additionally, miR‐26a expressions were higher 5.42 folds (<jats:italic>p</jats:italic> &lt; .05) on D8, 7.19 folds higher (<jats:italic>p</jats:italic> &lt; .01) on D16 in pregnant nulliparous and multiparous cows, and were 6.30 folds higher (<jats:italic>p</jats:italic> &lt; .001) on D8 and D16 according to non‐pregnant animals. PIF levels were greater in pregnant animals (<jats:italic>p</jats:italic> &lt; .05). Analyzing miR‐26a on D8 might be considered as sufficient in nulliparous cows. Pregnancy detection in multiparous cows can be made on the 16th day with this method. Furthermore, PIF evaluations may be sufficient on D10 in multiparous cows. Besides, PIF levels and miR‐26a expression levels might be used safely in field conditions and clinical applications.</jats:p>

<jats:title>Abstract</jats:title><jats:p>This study aimed to determine the effects of Coenzyme Q10 (CoQ10) in the freezing medium on functional and oxidative stress parameters and in vitro fertilization (IVF) rate of buffalo sperm. Collected samples were relocated to the laboratory for initial evaluation, gentle dilution in extenders, cooling (4°C, 2 h), equilibration (4°C, 4 h), packaging (straws, 0.5 mL), programmable freezing, and thawing (37°C, 30 s). Statistical analysis depicted that adding CoQ10 (100 μM) in a freezing medium caused a significant augmentation in total motility (%), average path, and straight‐line velocities (μm/sec) of buffalo sperm than control. Adding CoQ10 (100 μM) improved sperm progressive motility, rapid velocity, and functional parameters (%) compared to the control and 10 μM of CoQ10. Moreover, CoQ10 in a freezing medium caused a significant augmentation in seminal plasma catalase (U/mL) and glutathione reductase (GSH; nmol/10<jats:sup>9</jats:sup>) at 100 μM than control and other treatments. CoQ10 inclusion (100 μM) ameliorates seminal plasma superoxide dismutase (U/mL), glutathione‐S‐transferase (GST; nmol/mL/min) fructose (μg/mL), and ATP (nmol/million) than control. Furthermore, CoQ10 at 100 μM improved seminal plasma glutathione peroxidase (μM) levels than control, 10 μM, and 20 μM. Lastly, hydrogen peroxide (H<jats:sub>2</jats:sub>O<jats:sub>2;</jats:sub> nM) production was significantly lower at 100 μM than at control and 10 μM. CoQ10 (100 μM) caused a significant augmentation in the un‐capacitated pattern followed by a reduction in the capacitated pattern, and apoptosis‐like changes (%) than control, and other treatments, whereas viability was increased than control and other treatments. CoQ10 (100 μM) significantly improved the IVF rate in comparison with control, CoQ10 at 10 μM, and 20 μM groups. In conclusion, the addition of CoQ10 (100 μM) in the freezing medium can improve the quality and in vitro fertility of post‐thawed buffalo semen via its antioxidative effect. Further studies are needed to evaluate the effect of CoQ10 on the in vivo fertility of buffalo bull semen.</jats:p>

<jats:title>Abstract</jats:title><jats:p>This study investigated the impact of parity, period of calving, and season of calving on various production and reproduction traits in Hardhenu cattle. Third‐parity cows outperformed first and second‐parity cows, exhibiting significantly higher total milk yield (TMY), 305 days milk yield (305d MY), peak yield (PY), and artificial insemination per conception (AIPC) (<jats:italic>p</jats:italic> &lt; .01). The Lactation length (LL) was inversely related to parity, with first‐parity cows having extended lactations (<jats:italic>p</jats:italic> &lt; .05). The period of calving had a substantial influence on production traits. The season of calving was critical, affecting production traits differently across parities. First‐parity cows had the highest TMY and 305d MY during winter and summer calving, with summer calving associated with shorter LL (<jats:italic>p</jats:italic> &lt; .05). Second‐parity cows showed higher TMY and 305d MY during summer calving, while third‐parity cows had higher TMY in winter (<jats:italic>p</jats:italic> &lt; .01). PY followed similar patterns to TMY, with LL affected by the season of calving. Additionally, the study explored interactions between parity, period of calving, and season of calving on reproduction traits. Third‐parity cows had higher AIPC compared to first and second‐parity cows (<jats:italic>p</jats:italic> &lt; .01). Reproduction traits were also significantly affected by the period of calving, with cows calving in the 2017–2021 period displaying longer service period (SP), calving interval (CI), dry period (DP), and AIPC (<jats:italic>p</jats:italic> &lt; .01). These findings highlight the complex interplay of biological, environmental, and management factors in shaping the productivity and reproductive efficiency of Hardhenu cattle, emphasizing the need for multifaceted considerations to optimize herd performance.</jats:p>

<jats:title>Abstract</jats:title><jats:p>The equine foetal ovary has some unique characteristics that differ from other animals, such as ovary hyperplasia and high oestrogen secretion, and inverted location of cortex and medulla present in adult mare. The ovarian cortex supports the process of folliculogenesis and development, the synthetics and expression of oestrogen; however, the character‐related molecular mechanisms and specific biological functions in equine foetal ovarian cortex are still poorly understood. To explore the associated regulatory networks and molecular events of equine foetal ovary during the hyperplasia stage, we analysed the transcriptomic differences between the equine second‐trimester foetal ovarian cortex and adult ovarian cortex by RNA‐seq. There were 6334 differentially expressed genes (DEGs) present in foetal vs. adult, of which 3234 and 3100 DEGs were upregulated and downregulated, respectively. GO and KEGG were used for functional and pathway enrichment analysis of the DEGs. In particular, we found that some DEGs with high fold changes were related to steroid production and metabolism, such as <jats:italic>CYP11A1</jats:italic>, <jats:italic>CYP17A1</jats:italic>, <jats:italic>LDLR</jats:italic>, <jats:italic>STAR</jats:italic> and <jats:italic>SCARB1</jats:italic>, which were in line with the efficient oestrogen production in the equine foetal ovary. The transcriptome profile revealed the functional and developmental characteristics and gene expression patten of the ovarian cortex in the foetal and adult stages of the mare. Our study provides new insights into the molecular mechanism of equine second‐trimester foetal ovarian development through transcriptome analysis and provides insights for improving care or treatment for the pregnant mare and the foetus.</jats:p>

<jats:title>Abstract</jats:title><jats:p>We evaluated the effects of supplementation with catalase (CAT) and superoxide dismutase (SOD) antioxidants, isolated or combined, on the freezability of collared peccary sperm. Semen aliquots from ten individuals were diluted in Tris‐yolk with or without the presence of antioxidants CAT (200 or 400 IU/mL) and SOD (150 or 300 IU/mL) alone or in combination (CAT: 200 IU/mL + SOD: 150 IU/mL), and then cryopreserved in liquid nitrogen (−196°C). After 1 week, samples were thawed and evaluated for kinetic parameters, membrane functionality and integrity, mitochondrial activity, chromatin integrity, sperm morphology, sperm cell binding capacity and intracellular oxidative levels. Regardless of the use of antioxidants, the treatments did not differ in any of the evaluated parameters, except for the treatment with 300 IU/mL SOD, which showed the highest percentage of static cells (69.1 ± 4.4%) when compared to the group without antioxidant (51.6 ± 3.3%). In general, all samples maintained around 50% of functional membranes, 40% of intact membranes with mitochondrial activity, more than 99% of cells with condensed chromatin, as well as more than 70% of morphologically normal cells. Regarding the binding capacity, the minimum and maximum values found ranged from 33.8 to 194 spermatozoa bound to the perivitelline membrane. Finally, regardless of the presence of antioxidants, all thawed groups showed similar levels of reactive oxygen species (ROS). In conclusion, supplementation with CAT or SOD antioxidants, at the tested concentrations, does not bring benefits to freezability, and the increase in SOD concentration resulted in negative effects on sperm motility in collared peccary semen.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Scrotal surface thermography is a non‐invasive method for assessing testicular thermoregulation in stallions; however, few studies have explored the application of this technique concerning the thermal physiology of equine reproductive systems. This study aimed to evaluate the consistency of testicular thermoregulation in stallions over a year using thermography to measure the scrotal surface temperature (SST). Moreover, we assessed the best region for measuring the surface body temperature compared with the SST. Ten light‐breed stallions were used in the experiment. Thermographic images of the scrotal and body surfaces (neck and abdomen) were captured. Fresh, cooled and frozen–thawed semen samples were evaluated to verify the impact of thermoregulation on semen quality. Testicular thermoregulation was maintained throughout the year in stallions amidst changes in the external temperature, as evidenced by the weak correlation between the SST and ambient temperature. A lower correlation was observed between the environmental temperature and body surface temperature (BTS) obtained from the abdomen (BTS‐A; <jats:italic>R</jats:italic> = .4772; <jats:italic>p</jats:italic> &lt; .0001) than with that obtained from the neck (BTS‐N; <jats:italic>R</jats:italic> = .7259; <jats:italic>p</jats:italic> &lt; .0001). Moreover, both BTS‐A and SST were simultaneously captured in a single image. The consistent quality of the fresh, cooled and frozen semen suggests efficient thermoregulation in stallions throughout the year.</jats:p>

<jats:title>Abstract</jats:title><jats:p>We aimed to evaluate the effects of rumen‐protected lysine (RPL) supplementation during the close‐up period on uterine involution and the resumption of ovarian function in dairy cows. Fifty‐two multiparous Holstein cows were categorized based on parity and expected calving date and randomly assigned to the RPL or control (CON) groups. The RPL group received 80 g of RPL daily from day 21 before the expected calving date until parturition. Blood samples were obtained twice weekly from pre‐supplementation to 6 weeks postpartum. The onset of luteal activity postpartum was determined via ultrasonography twice weekly for up to 6 weeks postpartum. Uterine involution was tracked at 3 and 5 weeks postpartum through the vaginal discharge score, percentage of polymorphonuclear cells (PMN) in endometrial cytology samples, presence of intrauterine fluid, and gravid horn diameter via ultrasonography. Before supplementation, the RPL group showed amino acid imbalance, which was improved by RPL supplementation. There were no significant differences in the onset of luteal activity, percentage of PMN, intrauterine fluid, or the diameter of the uterine horn between the two groups. The vaginal discharge score in the RPL group decreased from 3 to 5 weeks postpartum, whereas that in the CON groups did not decrease. The number of cows with clinical endometritis was lower in the RPL group. Overall, RPL supplementation during the close‐up period enhanced vaginal discharge clearance, potentially averting clinical endometritis, but did not affect the first ovulation in dairy cows.</jats:p>

<jats:title>Abstract</jats:title><jats:p>High sperm cryotolerance is crucial to the successful cryopreservation of boar sperm. Evaluating the cryotolerance of boar sperm by using a rapid and convenient technique can enhance the commercial viability of these sperm. This study investigated the correlation between sperm parameters for three sample subsets—fresh sperm, sperm with H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>‐induced oxidative damage (hereinafter referred to as H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>‐induced sperm), and frozen‐thawed sperm—to identify the potential of these correlations to predict cryotolerance. A total of 64 sperm samples were obtained from 64 Duroc boars. The sperm parameters of the three subsets, where the frozen‐thawed sperm were analysed at 30 or 180 min after thawing, were determined, and the coefficients of correlation between these parameters were calculated. The results indicated that H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>‐induced oxidative stress resulted in decreases in various sperm parameters—including total motility (TM), viability (VIA), mitochondrial membrane potential (MMP), and live sperm with MMP (LMP)—but increased their coefficients of variation. Receiver operating characteristic (ROC) curve analysis revealed that the kinematic parameters of the H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>‐induced sperm effectively predicted those of the frozen‐thawed boar sperm at 30 min after thawing; the corresponding area under the ROC curve (AUC) was 0.8667 for TM and 0.8733 for progressive motility in the H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>‐induced sperm. For measurement at 180 min after thawing, the sperm membrane and mitochondrial parameters of the H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>‐induced sperm effectively predicted the LMP of the frozen‐thawed boar sperm; the corresponding AUC was 0.8489 for VIA, 0.8289 for MMP, and 0.8444 for LMP. To our knowledge, this is the first study to directly establish a strong correlation between post‐thaw boar sperm quality and H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>‐induced oxidative stress before freezing. Our proposed technique can serve as a valuable reference for the development of practical applications aimed at enhancing techniques for cryopreserving boar sperm.</jats:p>